Dinosaurs left behind skeletons, eggs, footprints, even fossilized poop. All these things help us imagine what the world of the dinosaurs looked like. But we really don’t have much of an idea what it sounded like. We can be pretty sure that the dinosaurs’ world echoed with the thud of gigantic feet, the splash of water, and the buzz of insects. But did dinosaurs bark, howl, grunt or growl? We don’t know.
However, scientists do think that one dinosaur “played a horn.” That dinosaur was Parasaurolophus (par-uh-sore-oh-loaf-us). Scientists have made models of the long, hollow crest on its head, and when they blew air through it, it made a deep, low tone, like a musical instrument.
The crest of Parasaurolophus was a very long, thin tube of bone. It began at the dinosaur’s nose and stretched up way above its head. On some Parasaurolophus the crest reached six feet long – longer than most people! This crest was hollow inside. A tube for air went up from each nostril to the tip of the crest and then curved back down like a trombone. All the air it breathed had to make that long journey. Not even Pinocchio had a nose that long!
In every other way Parasaurolophus was ordinary. It was one of the plant eaters nicknamed “duckbilled” because its mouth was long and flat like a duck’s bill. It stood on two strong back legs, with shorter front legs that it could also walk on or use as arms. It was about 30 feet long and 16 feet tall, and it probably weighed 3 or 4 tons. This was about the size of a bus – or an average dinosaur.
Size comparison of person and Parasaurolophuswalkeri
Parasaurolophus might have used the sounds it could make with its crest to communicate different messages, such as danger or food ahead. A herd might have honked at a Tyrannosaurus to go away. A special kind of honk might have attracted a mate.
Parasaurolophus also might have used its crest to push away branches in a thick forest. The cassowary, a large flightless Australian bird, uses its crest for that today. Another idea is that the crest brought cool air close to the Parasaurolophus’ brain to keep it from getting too hot. And it might have been able to smell through it, so it could seek out its favorite plants or tell when a meat eater was close by.
Scientists don’t know for sure if the Parasaurolophus used its crest in any of these ways. They continue to look for clues and ideas.
Scientists do know that Parasaurolophus had strong jaws which would be good for eating tough plants, such as pine needles, leaves, and different fruits and seeds. Its cheeks were loaded with good teeth for grinding things up. It even had three or four extra teeth above the ones that showed. That way if any of its teeth broke or wore out, new ones moved down. A Parasaurolophus may have grown more than 10,000 teeth during its lifetime.
Parasaurolophus lived right up to the end of the age of dinosaurs, outliving the other known duckbilled dinosaurs. But sixty-six million years ago, the last dinosaurs on earth died, including Parasaurolophus. Never again will the world echo with the sound of those gigantic feet or the honk of a Parasaurolophus calling to its friends.
Sources (Click Me!)
Norman, David. The Illustrated Encyclopedia of Dinosaurs. Crescent Books, 1985.
When the dinosaurs lived, they often had just one thing on their minds – FOOD! Whether a dinosaur ate plants or meat, getting food was a full-time job. Scientists have found evidence that at least one type of dinosaur went fishing for its food. That dinosaur was Baryonyx (BAR-ee-ON-ix).
Scientists know Baryonyx was a meat eater because it had the sharp curved teeth needed to cut through meat. But in many ways, it was different from other meat-eating dinosaurs.
Most meat-eating dinosaurs had strong jaws, heavy skulls, and enormous teeth, so they could slice through tough skin and bone. But Baryonyx’s jaws were not very strong, and its head was long and flat, like a crocodile’s. Its teeth were much smaller than most meat eaters’ – and it had almost twice as many of them. Baryonyx was not made for attacking other dinosaurs. It was made for catching fish.
A lot of animals like the taste of fish, but it takes a very special kind of animal to catch them. Fish dart about very quickly in the water. To catch them, an animal has to be even quicker. Fish are also very slippery. Holding onto them takes special claws or teeth.
So, how could Baryonyx catch fish? Scientists have suggested several ways. It might have stood by the edge of a shallow lake, waiting as patiently as a heron. When an unsuspecting fish swam by, it might have snapped it up. Its long mouth and many sharp teeth could have grabbed a quick-moving fish and held onto it no matter how much it wiggled.
Or the Baryonyx might have played crocodile. Some scientists picture it floating in the water, watching carefully. If a fish swam by, it was scooped up in the long mouth of Baryonyx.
Artwork by Jim Conaway
Another way it might have fished was with its front feet. It could use its front feet as hands. It had long, slender fingers which may have been used to grab fish. Or if it didn’t feel like grabbing, it might have gone “spear fishing.” The name Baryonyx means “heavy claw.” It got this name because it had a huge claw, one of the biggest dinosaur claws that has ever been found – 12 inches long! Scientists think Baryonyx had one of the super claws on each front foot. It could stand in shallow water, waiting. Then, when a fish swam past, it could stab quickly into the water and catch it.
Artwork by Jim Conaway
What makes scientists so sure Baryonyx ate fish? The first skeleton found had fish scales where its stomach would have been. They also found a few bones of a plant-eating dinosaur. How did Baryonyx hunt large plant eaters when it wasn’t a very big or strong dinosaur? Well, many scientists think it let a powerful meat eater like Megalosaurus do all the work. Megalosaurus might kill a plant eater too big for it to eat. Baryonyx could come by when it was done and eat the leftovers. So, the life of Baryonyx was like a vacation – lots of fishing and somebody else prepares the food!
Scientists don’t know much about how Baryonyx lived. They don’t know if it traveled in a pack or alone, they don’t know if it took care of its babies or left them on their own, and they don’t know if it had feathers or scaly skin. They can describe its size because the first skeleton found of it was 85% complete. It grew about 30-33 feet long and was about twice as tall as an average person. Its legs were short compared to some dinosaurs and lacked strong muscles, so it wasn’t a runner. It was not very strong in general, but its large claw would have made a great weapon to defend itself. Only a very big and very hungry meat eater would have bothered it.
Scientists are fascinated by this dinosaur because it’s so different from other dinosaurs. The wide variety of dinosaurs makes them very interesting to study, and each new discovery adds to our picture of what they were like.
Most of the dinosaurs that lived millions of years ago were peaceful plant eaters. But, every now and then, into this peaceful life came meat eaters!
If a plant eater didn’t want to become dinner, it had to be able to defend itself. Some plant eaters were very good at this. They had sharp claws or horns of their own. But one type of dinosaur didn’t need to fight back. All it had to do was squat down. This was the Ankylosaurus (an-KI-luh-sawr-us). The Ankylosaurus had thick, bony armor over almost all of its body.
The Ankylosaurus was a huge dinosaur. That alone would have been enough to discourage most meat eaters. It was just a little smaller than a bus – about 26 feet long and 7 feet tall, weighing as much as five tons. But it didn’t look like a bus – it looked like a tank.
Tanks are covered with metal armor. The Ankylosaurus’ armor was made from thick bands or plates of bone. Spikes and knobs were scattered across the back and over the head. The armor covered its back, neck, and head – even its eyelids!
Ankylosaurus head cast Tim Evanson, CC BY-SA 2.0, via Wikimedia Commons
The armor was probably very frustrating to a hungry meat eater. Even if a meat eater could dodge the knobs and spikes, all it would get was a mouthful of bony armor – and maybe a few broken teeth.
A meat eater had only one chance. The belly of the Ankylosaurus didn’t have any armor. If the meat eater could get to that soft spot, it could still have an Ankylosaurus snack. But all the Ankylosaurus had to do was crouch to the ground, folding its legs underneath. That way the only parts a meat eater could get to were covered with armor.
Illustration by Diana Magnuson
Some meat eaters probably tried to flip it on it back. If it were flipped over, the weight of its armor would prevent it from flipping back, much like a turtle. It would be completely helpless. However, trying to flip an Ankylosaurus was like trying to flip a tank. Most ankylosaurs were much too heavy for even the strongest meat eater to budge. And, of course, it was hard to find a place to grab on, with all those spikes and knobs in the way.
If a meat eater kept on bothering an Ankylosaurus, it ran the risk of provoking the creature into an attack. At the end of its tail, the Ankylosaurus had a huge, bony club. The club was about 16 inches wide and made of solid bone. The muscles in the tail were very strong. If an Ankylosaurus swung its club hard enough, it could probably have knocked down any other dinosaur, even a Tyrannosaurus. It might have been able to break a meat eater’s leg – or its skull – with that club. It certainly would have made that meat eater very sorry it ever wanted an Ankylosaurus for dinner!
Illustration by Diana Magnuson
Ankylosaurus had some trouble finding its own dinner. It was hard for it to move its head and neck because of all that armor. And it certainly couldn’t rear up on its back legs with all that heavy bone to lift. That meant that it could only feed on plants that grew close to the ground. Maybe that wasn’t all bad, though. Every now and then it might scoop up some ants or a few beetles for a tasty dessert.
You might think that the Ankylosaurus with its heavy armor was a slow-moving dinosaur, but it was more like a rhinoceros than a turtle. A rhinoceros is very large and heavy, but it can run fast. Ankylosaurus wasn’t as fast as a rhino, but it could run as fast as 6 mph, which is about as fast as most people can run. The powerful leg muscles of Ankylosaurus helped it to move quickly if it needed to.
Ankylosaurus was the biggest armored dinosaur that we know, but it was not the only one. It had many relatives. Some had more spikes. Some had few or none at all. Some had tail clubs. Some did not.
Hylaeosaurus UnexpectedDinoLesson, CC BY-SA 4.0, via Wikimedia CommonsYuxisaurus Xi Yao, Paul M Barrett, Lei Yang, Xing Xu, Shundong Bi, CC BY 4.0, via Wikimedia Commons
But most of them were good at surviving. Many of the armored dinosaurs lived until the very end of the age of dinosaurs. It wasn’t easy living in the same world as Tyrannosaurus, but it could be done – by a walking tank!
Sources (Click Me!)
“Ankylosaurus.” Natural History Museum of London. n.d. https://www.nhm.ac.uk/ discover/dino-directory/ankylosaurus.html
“Cretaceous Insects.” Western Australian Museum. n.d. https://museum.wa.gov.au/ explore/dinosaur-discovery/cretaceous-insects
Norman, David. The Illustrated Encyclopedia of Dinosaurs. Crescent Books, 1985.
Rasmussen, Patty and Talon Homer. “Ankylosaurus: A Tank-like Herbivore With a Killer Club Tail.” How Stuff Works. 10 July 2024. https://animals.howstuffworks.com/ dinosaurs/ankylosaurus.htm?utm_source=facebook&utm_medium=social&utm_campaign=hsw-owned&utm_content=animals&fbclid=IwY2xjawFYdItleHRuA2Flb QIxMQABHSJZrzMY8s_ckpGF7a0h_hX_66x-bgLwyX_Zqb-4gJSO4DdqauNWL6RUmA_aem_vUroiI23KZyLQ6TE2xysxw
Riehecky, Janet. Ankylosaurus. The Child’s World, 1991.
We finally conclude our deep dive into the extinction event that killed the dinosaurs. We end with Robert dePalma, whose findings shaped our understanding of the asteroid.
At first it was just disappointment. Thirty-year-old graduate student, Robert dePalma, was excavating a fossil site on a ranch in North Dakota. When he began digging in 2021, he had hoped to find layers of sediment that would show the years leading up to the end of the Cretaceous Time Period. The site was a large area, covering about two acres and measuring about three-feet deep, but it was clear the entire layer had been laid down all at once by some kind of flood. There were fish fossils, but they broke apart into tiny flakes when he tried to dig them out.
North America at the End of the Cretaceous Period Ron Blakely, Colorado Plateau Geosystems is credited for the maps, in the paper, and Terry A. Gates et al are stated to be the copyright holders for the paper and its contents, CC BY 1.0, via Wikimedia Commons
He continued to dig, though, and he found tiny, white/gray bits that looked like sand. When he looked at them under a magnifying glass, he recognized their tear-drop shape as belonging to microtektites. Tektites, as mentioned in last week’s blog, are created when rock becomes so hot that it turns to liquid. They can be formed by volcanos or by an asteroid hitting the earth. The liquid rock is flung into the air in small bits until it goes high enough the air cools them. As they fall to Earth, they form tear-shaped, glass fragments. Over millions of years, they turn to clay. The tektites he found were so small they were classified as microtektites. DePalma found millions of them. He knew the bed he was digging in was from the end of the Cretaceous Time Period. It dawned on him that the microtektites might be from the asteroid that hit the Earth then.
DePalma continued his excavation. He found an amazing number of fossils. Most of the time fossils are flat, crushed by layers and layers of rock, laid down over time. But many of these fossils were three-dimensional because they had been deposited and covered immediately, and the sediment around them acted as support.
He found new species of fish and a variety of plants, including tree trunks smeared in amber. The amber contained what appeared to be asteroid debris. He suspected that the site he was working on had been formed the very day the asteroid hit! If that was true, it was an incredible find!
As a child and young adult, dePalma had collected bones and fossils. He lent them to a nearby museum where he also reconstructed some dinosaur skeletons. But when the museum went bankrupt, they refused to return his collection. After that he was very careful about the fossils he excavated. In the United States, fossils belong to whoever’s property they are found on and can be sold to anyone. It is not unusual for a paleontologist or commercial fossil collector to sign a contract with a private land owner for an excavation. They usually agree to split the profit on any fossils that are found and sold. Museums and universities don’t like this arrangement because important finds can disappear into private collections.
Realizing that this site was potentially one of the most important ever found, he entered a long-term agreement with the ranch owner. The details of the agreement have been kept private.
Over the next several years, dePalma continued to excavate. He confided in only three other people what he had found, including Walter Alvarez, the man who had originally proposed the asteroid theory. DePalma did publish a paper that described a hadrosaur bone he’d found with a tyrannosaur tooth embedded in it. The bone had healed, indicating that the hadrosaur had gotten away after the attack, which dePalma said proved Tyrannosaurus hunted live prey. Scientists have long debated whether Tyrannosaurus was just a scavenger who lived by finding meals that were already dead or if it hunted live prey. DePalma’s evidence was not taken very seriously because he was just a student and a commercial fossil collector.
Continued excavation at the site revealed a paddlefish, but underneath it was a mosasaur tooth. A paddlefish is a freshwater fish, but a mosasaur is a giant, saltwater reptile. How could fossils of both be in the same site? DePalma and the others tried to come up with a theory to explain this, but they couldn’t.
Then he found small impact craters, about three inches across. At the bottom of each crater was a normal-sized tektite. DePalma was sure they had to be from the asteroid that ended the Cretaceous Period, even though the impact site was about 2000 miles away. He arranged to have a laboratory compare the tektites to material from the Chicxulub (CHICKS-ih-lube) Crater. They matched! The asteroid impact was so explosive that debris was thrown 2000 miles away!
For years dePalma had worked on the site in secret, sharing it with just a few others. But in 2019, he invited a reporter from New Yorker magazine to see the site and tell the world its story. When the story was published, the scientific community was skeptical. The normal procedure for announcing a significant discovery would be to submit a paper to a peer-reviewed journal where experts would evaluate the evidence before it was published, not submit it to a literary magazine. Many scientists disparaged his theories because dePalma was just a student only working on a PhD, a nobody who dug up fossils to sell rather than to study. But they sold dePalma short, as evidence he was right continued to pour in. (And he did eventually publish papers in peer-reviewed journals.)
Depiction of a Cretaceous forest of what is today the Tanis site, in North Dakota, hours after the K-Pg impact. Notice a burnt carcass of a Thescelosaurus, an impaled turtle, a small mammal and a small ornithuran avialan. YellowPanda2001, CC0, via Wikimedia Commons
DePalma has named the site Tanis, after an ancient Egyptian city. In the late Cretaceous, a large inland sea stretched from the Gulf of Mexico to what is now the U.S./Canadian border. What is now North Dakota was subtropical. DePalma and the people he has now working with him on the site have determined that Tanis was a sandbar located between a river and a forest. They think that when the asteroid hit in the Gulf of Mexico, it created a gigantic earthquake. It took maybe ten minutes for the shock waves to reach Tanis. The disturbance caused giant waves to form on the inland sea shown in the map above. They flung sea creatures, such as the mosasaur, at Tanis, many miles away. In addition, waves were formed in the nearby river, flinging freshwater creatures onto the site. DePalma found a turtle that was flung so hard that a tree branch went right through its body.
Continued excavation has also revealed
Fish with asteroid debris clogging their gills,
Ant nests with the ants still in them and asteroid debris in their tunnels,
Large feathers that likely came from a large dinosaur,
Broken bits from almost all the dinosaurs known to have lived in that area during the late Cretaceous,
A small burrow inhabited by a small mammal,
Dinosaur eggs and hatchlings,
Pterosaur bones,
A partial mummified Thescelosaurus with its skin still intact,
And pieces of the actual asteroid preserved in amber.
DePalma and his crew continue to work on the site. It will take years to explore it thoroughly. Right now, though, it’s an amazing picture of what happened the day the dinosaurs died.
What is the evidence that an asteroid hit the Earth? The history of the Earth is recorded in rocks…
One of the most basic things geologists study are layers of rock. You’ve probably seen them.
Rock layers are easily seen in the Grand Canyon
These layers are laid down by sand, river silt, lava, and other inorganic ground cover. Some are formed quickly; others take thousands of years. Earthquakes can shove some layers up and others down. Each layer represents an era of time.
Scientists can determine the age of layers of rock by looking at fossils and elements found in the rock. Some elements are especially helpful in this because they change over time. For example, some forms of potassium change into argon. Scientists know how long it takes for this to happen (millions of years), so by measuring how much of a sample is still potassium and how much argon, they can tell how old the rock is. They can also do this with some uranium, which changes into lead. It’s more complicated than that, but that’s the basic idea.
Scientists have known for a long time that there is a layer of rock that marks the end of the dinosaurs. It’s called the K-Pg boundary and it dates to 66 million years ago, (K stands for the German word for Cretaceous and the Pg for Paleogene, the next time period.) Below that layer dinosaur fossils are found. No dinosaur fossils have ever been found above it.
At first, scientists believed that this extinction happened gradually. Dinosaurs died out because they were replaced by “superior” mammals. But in the mid-1970s, while studying layers of rock in Italy, geologists Walter Alvarez and Bill Lowrie, noted that the layer of rock below the K-Pg boundary had loads of microfossils of sea creatures in it, but a thin layer of clay just above it had almost none. It looked like nearly all these creatures had died suddenly. Alvarez realized that their near extinction occurred at the same time with a much bigger extinction – the dinosaurs!
Cretaceous-Tertiary boundary clay Jeffrey Beall, CC BY 4.0, via Wikimedia Commons
Alvarez talked to his father, Luis Alvarez, a Nobel prize winning physicist, about the problem. His father had the idea of trying to look for the element iridium in order to tell if the layer of clay was deposited quickly (which could mean a catastrophe killed the dinosaurs) or gradually (which would mean scientists were right about dinosaurs dying off slowly). Iridium comes from asteroids. It’s very, very rarely found on Earth. But dust from asteroids drifts down through the atmosphere in tiny amounts at a consistent rate. If there was a lot of iridium dust, that would mean the extinction happened gradually. If a small amount, then it happened quickly.
But father and son were not prepared for what they found: a lot of iridium. That should have meant that the layer was laid down gradually, but it was too much iridium, nine times more than just dust could account for. They decided to look in another location of the K-Pg boundary to see if they found the same thing. They found a site in Denmark. It also had lots of iridium. Later a site in Spain got the same result.
Father and son discussed the idea that the iridium could have come from an asteroid hitting the Earth, but they couldn’t figure out how one impact could cause worldwide extinction. Walter presented the iridium data at a conference and met with lots of resistance. Scientists did not want to let go of the idea that dinosaurs had died out gradually.
Artist impression of asteroid impact Donald E. Davis, Public domain, via Wikimedia Commons
Luis then had the idea that a large enough impact would cast so much debris into the air that sunlight would be blocked. With no sunlight, plants wouldn’t grow. Plant eaters would have nothing to eat and would die. Then meat eaters would have nothing to eat. This could cause mass extinction. Meanwhile, reports came in from all over the world showing lots of iridium in the K-Pg boundary. But nearly all scientists still rejected the idea of an asteroid impact leading to mass extinction.
Over the next decade other evidence of an impact was found in rocks. Scientists found shocked quartz in the K-Pg boundary. Shocked quartz is formed from a powerful shock wave (like an earthquake) passing through rock and deforming the structure inside regular quartz. An asteroid impact would have sent a shock wave like that through the ground. They also found tektites, which are made when rock is heated so hot it becomes liquid (usually by a volcano). Bits of liquid rock are flung into the air. When they get high enough, the rock solidifies, and it falls to Earth in a distinctive tear-drop shape. An asteroid hitting the Earth would have made an explosion so hot it would have melted the rock and produced tektites. Scientists also found sand deposits that indicated a tsunami had occurred and soot from the worldwide firestorm there would have been.
All this was great, but skeptics still held out. They asked, “If an asteroid hit the Earth, where is the crater that it would have formed?” It wasn’t until 1990 that scientists found that the Gulf of Mexico had been hiding the crater. The Chicxulub Crater in the Yucatan Peninsula became the smoking gun that confirmed that a huge asteroid had indeed struck the Earth. Scientists were able to date the crater to about 66 million years ago – the end of the Cretaceous Period and the end of the dinosaurs. This finally convinced most scientists.
The Formation of Chicxulub Crater The original uploader was David Fuchs at English Wikipedia., CC BY 3.0, via Wikimedia Commons
Further research has strengthened the asteroid theory. The Chicxulub Crater is the largest impact crater on Earth, about 120 miles wide and 18 miles deep. The asteroid that hit it was about six miles wide and moving about 45,000 mph. As I said in my last blog, it hit with so much power that it blew a huge hole in the Earth and melted thousands of cubic miles of rock, throwing massive debris into the air. We now know that the rock bed of the impact site was limestone and anhydrite. These rocks would have released vast amounts of carbon dioxide, carbon monoxide, and sulfur into the air when they exploded. The sulfur would have combined with water to form acid rain. All this would have contributed to the extinction event by contaminating the air and reducing oxygen.
Imagine the horror of that day – an explosion 10 billion times bigger than the WWII atomic bomb, a tsunami with one-thousand-foot-high waves of water covering what is now Mexico and the southern United States, a magnitude 10 earthquake, a worldwide firestorm, and billions of tons of debris, ash, and acid rain polluting the atmosphere. And don’t forget, as I mentioned last week, there were huge volcanoes erupting in what is now India. We don’t know if the asteroid had anything to do with those eruptions or not, but they certainly contributed to the extinction event. About 75% of life on Earth became extinct.
It’s hard to picture it all, but a recent discovery in North Dakota gives us a freezeframe of that day. That site will be the subject of next week’s blog.
Everyone knows an asteroid killed the dinosaurs. But is that all we know? Join me as we go down the rabbit hole of how the dinosaurs went extinct…
Sixty-six million years ago, life on Earth was very different from today. Trees, ferns, and flowering plants covered the land. There wasn’t any grass (despite what the picture below shows. I couldn’t find a free Cretaceous scene anywhere without green ground). Grass hadn’t evolved yet.
User:Debivort, CC BY-SA 3.0, via Wikimedia Commons
The only mammals were small creatures, no bigger than about three feet long. Dinosaurs dominated the planet. There were small dinosaurs, medium-sized dinosaurs and BIG dinosaurs. They lived in every part of the world. They lived in valleys and on mountains. They lived in dry places and wet places. They lived in forests and on open plains. They had ruled the Earth for 180 million years, and it seemed they would continue to do so indefinitely.
But out in space an asteroid was plunging toward Earth. It was about six miles wide and the height of Mt. Everest. When it reached the Earth’s atmosphere, it would have looked like a fireball brighter than the sun. It was seen, though, for only a few seconds before it hit the Earth because it was hurtling through the air at about 45,000 mph! It hit in the Yucatan Peninsula in Mexico, forming a crater that covers a large portion of the Gulf of Mexico. The crater has been named Chicxulub (CHICKS-ih-lube) Crater.
NASA/JPL-Caltech, modified b, Public domain, via Wikimedia Commons
The asteroid hit with a force 10 billion times larger than the atomic bomb detonated on Hiroshima, blowing a hole in the ground 120 miles wide and 18 miles deep. Imagine how loud that explosion must have been! In an instant, the intense heat of the explosion vaporized the asteroid and turned thousands of cubic miles of rock into liquid and spewed it into the air, like a colossal volcano erupting. Anything within 600 miles or more would have been instantly incinerated by the fireball. A combination of soot, sulfuric gases, and extremely fine dust was flung into the atmosphere. For the next several hours, titanic winds blew this debris around the whole Earth. They ignited a world-wide firestorm that probably killed most of life on Earth. In addition, a mega-earthquake shook all of Mexico and Central America, the southern United States, and as far south as far as Argentina. The earthquake (magnitude 13 – likely the biggest earthquake the Earth has ever felt) triggered giant tsunamis and mudslides. One-thousand-foot-high waves of water hit the coast where now Texas, Alabama, Mississippi, northern Mexico, and Cuba lie. Secondary waves traveled as far as what is now North Dakota.
Continent placement at the end of the Cretaceous Era Merikanto, CC BY-SA 4.0, via Wikimedia Commons
Life that somehow survived this, now faced another horror. Dust and soot lingered in the atmosphere blocking most of the sunlight for at least a year. Without sunlight plants couldn’t grow and thrive. Plant eaters lost their food source and died. Meat eaters lost their food source and died. In addition, the lack of sunlight lowered the temperature on Earth by about 80° Fahrenheit.
As if this weren’t bad enough, volcanos in India had been erupting at this same time, with lava flows covering 190,000 square miles of land, killing all life in that area. The eruptions also added more toxic fumes and debris to the atmosphere.
Scientists disagree about how long it took, but about 75% of all life on earth, plant and animal, died because of the asteroid hit and the volcanos, including all the dinosaurs (except birds which most scientists believe are direct descendants of dinosaurs). Some small animals survived, including the ancestors of today’s frogs, snakes, lizards, alligators, crocodiles, a variety of insects, birds, and mammals.
How do we know all this happened? I’ll explain in my next blog.
This blog is the first in a series that will explore the timeline of Earth’s history, from the formation of the planet to the dominance and eventual extinction of dinosaurs.
This blog is about dinosaurs in time; that is, dinosaurs in the timeline of Earth’s history. Not dinosaurs on time, because dinosaurs were hardly ever on time seeing they didn’t have clocks.
Scientists say the Earth was formed 4.6 billion years ago. At first it was just molten lava, hundreds of miles deep. Over millions of years the Earth cooled and a crust appeared.
The first lifeform that existed was a sort of blue-green algae. Then other lifeforms appeared, including shellfish. That whole time period of more than four billion years is called the Precambrian Eon. From 542 million years ago to the present age is the Phanerozoic Eon. It’s divided into three eras, the Paleozoic, the Mesozoic, and the Cenozoic. During the Paleozoic (from 541 to 252 million years ago) life began to bloom. The first fish, first amphibians, and the first reptiles appeared. The first plants also began to grow. But then a massive extinction wiped out 90% of life on Earth. Its cause is not known, but it ended the Paleozoic Era making way for the Mesozoic Era (from 252 to 66 million years ago).
That’s when we get to the good stuff: Dinosaurs! The Mesozoic is divided into three time periods: the Triassic, the Jurassic, and the Cretaceous. And about halfway through the Triassic Period a new kind of animal evolved: a dinosaur.
Timeline of Earth (MYA means millions years ago)) Thanaben, CC BY-SA 3.0, via Wikimedia Commons
During the Triassic the Earth was warm and fairly dry, with ice at the north and south poles. (Although Santa Claus hadn’t moved in yet.) Most of the large island masses gathered together in a supercontinent called Pangaea. Conifers, cycads (which looked like mutant pineapples), and ferns were the most common plants, and reptiles ruled the planet. It was about 240 million years ago that the first dinosaurs appeared. They were small and walked on two legs. Over millions of years, they began to change, and many varieties of dinosaurs appeared. Some were meat eaters; others, plant eaters. Some grew to large sizes. These included Riojasaurus and Lessemsaurus. But then 201 million years ago, another mass extinction took place, probably caused by volcanic action in the Atlantic Ocean, rising sea levels, and climate change.
Pangaea breaking up Public Domain U.S. Dept. of the Interior
Some dinosaurs survived and moved into the Jurassic Period. Pangaea broke apart and, over millions of years, formed the continents we know today. Their environment ranged from arid deserts to lush tropical forests. Conifers and ferns were the main plants. Most importantly, dinosaurs dominated each new continent. Some of the largest of all dinosaurs evolved during this time, including Alamosaurus, Argentinosaurus, and Dreadnaughtus. The fierce predator Allosaurus also lived in this time period. And the earliest known bird, Archaeopteryx, emerged in the late Jurassic.
About 140 million years ago, life on Earth began to change dramatically. Many new life forms emerged while others went extinct. There doesn’t seem to have been any big extinction event, but scientists date this as the beginning of the Cretaceous Period (my favorite time period!). Flowering plants appeared, but there were still a lot of the familiar conifers and ferns. Many new, strange-looking dinosaurs dominated the environment. Tyrannosaurus became an apex predator and weird dinosaurs, such as Parasaurolophus, Ankylosaurus, Triceratops and Pachycephalosaurus roamed around.
Dinosaurs were so abundant it seemed they would rule Earth forever – but an asteroid colliding with Earth 66 million years ago brought their world to an end. The Cenozoic Era began, with an opening for mammals to dominate the world. The asteroid collision will be the subject of my next blog.
Stegosaurus is one of the most iconic herbivores, but is also one of the most peculiar…
Many dinosaurs are strange. But one of the strangest is Stegosaurus. Imagine what you would look like if you walked on your feet and your elbows! Well, that’s sort of what Stegosaurus looked like. Its back legs were twice as long as its front legs. That meant its hips were stuck way up in the air – 9-13 feet! Its head and shoulders were close to the ground, and its back curved like a slide down to its tail. From front to back it was about 24-30 feet long, and it weighed about 5 ½ tons. In a bowling alley, it would take just two stegosaurs to stretch from the beginning of the alley all the way down to the bowling pins.
Stegosaurus skeleton at the Field Museum of Natural History in Chicago
That was certainly a strange shape, but Stegosaurus had an even stranger mouth. The front of its mouth was a beak, like that of a parrot or turtle. Most plant eaters have strong teeth that can grind up food, but not Stegosaurus. In the back of its mouth, it had rows of small, weak teeth. Its jaws could only move up and down, not to the side, which made chewing hard. As you can imagine, all this made it hard for Stegosaurus to eat. It could break off a mouthful of plants, but it couldn’t really chew them up very well before swallowing them. So, most things went down whole. There’s no evidence to indicate that it ate rocks (called gastroliths) as did other dinosaurs that couldn’t chew. The rocks helped break up the food in a special sac called a gizzard. But Stegosaurus didn’t do this. So, scientists have no idea how this strange creature managed to digest its food.
Stegosaurus not only had trouble eating – it also had trouble thinking. The Stegosaurus had a tiny head and probably the smallest brain compared to its size of any dinosaur. It was only about as big as a golf ball or walnut.
Stegosaurus might not have been very smart, but it knew enough to avoid somebody who tried to take a bite out of it. And there were plenty of creatures that wanted to take a bite out of Stegosaurus.
The Stegosaurus lived at the same time as the fierce Allosaurus and many other meat eaters. It couldn’t run fast, and it couldn’t think fast. It had to have some way to protect itself – so it grew a very strange weapon. Most dinosaurs that needed to defend themselves grew sharp claws on their feet or horns on their heads. But Stegosaurus did things backwards. It grew four, foot-long spikes on the end of its tail!
These spikes were good weapons and helped the Stegosaurus, but they were not good enough to fight off a determined attack. So, Stegosaurus’ best chance for survival was either to hide from meat eaters (and it was too big to do that!) or to stay with a herd of stegosaurs. Like any bully, an Allosaurus would rather attack a Stegosaurus found alone than one with a lot of friends nearby.
Probably the weirdest thing about Stegosaurus was the plates on its back. Scientists have wondered whether there was one row of plates or two, whether they stood up straight or lay down flat, and whether they were arranged in pairs or alternated. They have also wondered what the plates were for.
They weren’t dinner plates – but they may have helped keep Stegosaurus from becoming someone else’s dinner, serving as defense. This isn’t too likely because their whole sides had no covering. Just protecting the top wasn’t very effective.
Or the plates may have worked to keep the Stegosaurus from becoming too hot. Their position and shape seem designed to pull heat from the body of Stegosaurus and let the wind carry it away. But dinosaur species similar to Stegosaurus, such as Kentrosaurus, have spikes instead of plates, which wouldn’t work as heat dispersers. Most likely, the plates may have been just for display, to help Stegosaurus attract a mate. Scientists have considered all of these ideas, but they have not been able to agree. They continue to study the plates, but they may never know for sure why Stegosaurus had them.
Kentrosaurus Connor Ashbridge, CC BY-SA 4.0, via Wikimedia Commons
Scientists also don’t know much about the kind of life Stegosaurus led. Scientists have found Stegosaurus footprints which seem to indicate it traveled in herds, living on flat floodplains and in conifer forests bordering rivers. It is likely it ate plants that grew close to the ground, such as mosses or ferns. They think it laid eggs and that it probably left its babies on their own to take care of themselves because they weren’t smart enough to take care of them. Many reptiles, such as sea turtles and snakes, do this. But scientists don’t know for sure. There will always be things we don’t know about Stegosaurus. But that’s part of the fascination of this strange creature.
Dinosaurs varied in size, most know the giants, but today we are tackling one of the smallest dinos: Compsognathus
When most people think of dinosaurs, they think of huge creatures. And many of the dinosaurs were enormous. Supersaurus was longer than a basketball court, and Sauroposeidon (SORE-oh- poe- seye-don) was as tall as a five-story building. But not every dinosaur was huge. During the Jurassic Time Period, when many of the biggest dinosaurs lived, there also lived Compsognathus (KOMP-sog-nath-us)). Compsognathus was a tiny dinosaur, not much bigger than a chicken.
My life-size model of Compsognathus compared to my cat.
The largest Compsognathus ever found was not quite four feet long – and most of that was just its tail. It stood about 11 inches high at the hip and weighed about 9-12 pounds. There were some advantages to being a tiny dinosaur in a land of giants. Many big meat eaters were likely to overlook such a small animal. They could feast on hundreds of pounds of tasty plant eaters. Why should they bother with one, stringy, little mouthful?
Of course, it wouldn’t be so great to be caught in the path of one of the giant dinosaurs. Some of the really big ones could step on a Compsognathus and hardly know it – the way you might step on a large bug.
But Compsognathus wasn’t likely to get stepped on often. Scientists say it was built for speed with hollow bones and a slender, streamlined body. It ran on two long, strong, back legs, and its tail helped keep it balanced as it ran. It could zip along dodging giant dinosaurs with ease.
It may not have needed to dodge too many other dinosaurs. Only two skeletons of Compsognathus have been found, and both of them seemed to have lived on atolls, islands that have a lagoon in their center. If all Compsognathus lived on these types of islands, they may have been the biggest predator on them.
Satellite picture of the Atafu atoll in TokelauAtafu.jpg: NASA Johnson Space Center derivative work: Talkstosocks, Public domain, via Wikimedia Commons
Compsognathus still needed to be speedy – to catch its own food. Scientists think Compsognathus ate such things as insects, frogs, and small lizards. It took speed to catch such quick-moving creatures. One skeleton of a Compsognathus was found with a particularly fast lizard in its stomach. The lizard may have been fast, but Compsognathus was faster.
Compsognathus skeletonH. Zell, CC BY-SA 3.0, via Wikimedia Commons
Compsognathus could grab its lunch with the long fingers on its hands. It had three fingers on each “hand,” but only two of them were usable. Each one of them had a very long claw, good for grabbing food. Once it caught its lunch, Compsognathus could crunch its victim with its many sharp, pointed teeth, though it may have just swallowed it whole. The name Compsognathus means “pretty jaw,” but if you were a pterosaur (TAIR-uh-sore), grounded with a broken wing, you wouldn’t think those jaws were so pretty.
It’s hard for scientists to learn much about Compsognathus and other little dinosaurs because so few of their skeletons are ever found. Many such dinosaurs were probably gulped down whole by big meat eaters. Even if a tiny dinosaur were fossilized, chances are no one would find it. It’s just much easier to find a six-foot bone than a two-inch one.
Rigorius, CC BY-SA 4.0, via Wikimedia Commons
Scientists have found a few dinosaurs that were as small or even smaller than Compsognathus. These include Microraptor which is in the same family as Velociraptor and Utahraptor, except it was only two feet long and weighed about two pounds, and Aquilops, (uh-QUIL-ops) which was a little bigger – 3-5 pounds. Its descendants included the mighty Triceratops. Studying them alongside Compsognathus makes scientists think that any small dinosaur must have been quick and active.
Scientists want to learn all they can about what made small dinosaurs special. They would like to know whether they lived in packs or by themselves. In the Jurassic Park franchise (where they were called “compis”) a pack of Compsognathus were shown working together to attach someone, but we don’t know if that was true or not. Scientists would also like to know whether or not they took care of their babies or left the babies alone to fend for themselves. And they would like to know whether they lived in fear of the big dinosaurs or simply ignored them.
So far, the fossil record hasn’t answered those questions. In the meantime, scientists continue to search for clues. One thing is already known – tiny dinosaurs are just as fascinating as huge ones!
CompsognathusNobu Tamura (http://spinops.blogspot.com), CC BY-SA 3.0, via Wikimedia CommonsSources (Click Me!)
Norman, David. The Illustrated Encyclopedia of Dinosaurs. Crescent Books, 1985.
Riehecky, Janet. Compsognathus. The Child’s World, 1991.
Strauss, Bob. “The 19 Smallest Dinosaurs and Prehistoric Animals.” ThoughtCo. 5 Apr. 2023, thoughtco.com/smallest-dinosaurs-and-prehistoric-animals-1093812.
As I wrote a few weeks ago, there are some serious contenders for Tyrannosaurus’ crown as the biggest, fiercest land carnivore of all time. Giganotosaurus and Megaraptor could certainly give Tyrannosaurus a battle, but this week’s contenders, from Africa, are even more powerful.
Carcharodontosaurus (Kar-KAR-oh-don-toe-SAWR-us) lived in Northern Africa during the late Cretaceous Period 99 to 94 million years ago. Its name means “shark-toothed lizard,” and its long jagged-edged teeth are much like those of a shark.
Most estimates rank Carcharodontosaurus as about three or four feet longer than Tyrannosaurus. It’s hard to tell because scientists have found only some tens of bones and a number of teeth from it.
Even if Carcharodontosaurus is slightly larger, Tyrannosaurus still has a number of advantages. Smithsonian Magazine reported that Tyrannosaurus’ bite force was almost 12,800 pounds, stronger than any other animal that ever walked on land. (Megalodon, an enormous extinct shark, does have it beat at 41,000 pounds. There was also an extinct crocodile named Purussaurus which had a bite of 15,500 pounds of force.) Tyrannosaurus’ bite was stronger than the force of an average-sized African elephant dropping on you. (I don’t want to even think what that means about Megalodon’s bite.) Tyrannosaurus’ teeth are shaped like bananas. The rounded shape is very effective at breaking bones. Carcharodontosaurus’ teeth were shaped differently. They were thinner, more like the blade of a knife. They were meant for shearing meat from bones. They might have broken if Carcharodontosaurus bit directly into thick bones.
Tyrannosaurus also had an advantage in eyesight. Its eyes were more forward looking than Carcharodontosaurus’. This gave Tyrannosaurus a wider range of sight, enabling it to see more of what was in front of it. Because of the shape of Carcharodontosaurus’ skull, it would have had to drop its head toward its chest to see any distance ahead. This likely meant it hunted its prey by ambushing them, rather than chasing after them. Regardless, if the two had ever met, it would have been a titanic battle.
Franko Fonseca from Redondo Beach, USA, CC BY-SA 2.0,via Wikimedia Commons
And then there’s the biggest of the top five, Spinosaurus. It also lived during the late Cretaceous Period and was found in North Africa. This creature was about 49 feet long and weighed just over eight tons. However, its back legs were much shorter than Tyrannosaurus’, making it about 9 feet tall at the hip compared to Tyrannosaurus’ 12-15 feet in height. However, if the sail on Spinosaurus’ back is included, then it was 15-16 feet tall.
Durbed, CC BY-SA 3.0, via Wikimedia Commons
It’s difficult to compare its power to the other three because it was shaped differently and lived a different kind of life. It was a little thinner, with a large sail on its back, a paddle-shaped tail and its jaws were long and narrow like a crocodiles’. Its teeth were like overturned ice cream cones instead of curved with jagged edges. Scientists think that it hunted at least part of the time in the water and that on land it stayed near the coast and ambushed its prey, rather than running it down. Its likely that, despite its huge size, its shorter legs would have made it less agile than Tyrannosaurus. Its tail would have been a formidable weapon for knocking other dinosaurs around, but that might not be enough.
Figure 1 (left) Spinosaurus tooth – 1 Jiří X. Doležal (about me), CC BY-SA 3.0, via via Wikimedia Commons. Figure 2 (right) Tyrannosaurus tooth
Scientists don’t know which of these dinosaurs was most powerful. Even though it’s been many years since Giganotosaurus, Megaraptor, Carcharodonotosaurus, and Spinosaurus were discovered, scientists still know very little about them. It takes a long time for fossil bones to be excavated and studied. For me, however, Tyrannosaurus still holds its crown by virtue of its long teeth, large brain, and powerful bite. But never forget that there is another alternative: any day a paleontologist might dig up a new dinosaur that could take on all of them.
What do you think?
Sources (Click Me!)
Aureliano Tito, Aline M. Ghilardi, Edson Guilherme, Jonas P. Souza-Filho, Mauro Cavalcanti, and Douglas Riff . “Morphometry, Bite-Force, and Paleobiology of the Late Miocene Caiman Purussaurus brasiliensis.” PLOS ONE. 17 Feb. 2015. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0117944.
Novas, Fernando, E., Diego Pol Juan I. Canale; Juan D. Porfiri; Jorge O. Calvo. “A bizarre Cretaceous theropod dinosaur from patagonia and theevolution of Gondwanan deomaeosaurids. Proceedings: Biological Sciences, Mar2009, Vol. 276 Issue 1659, p1101-1107, 7p.
Richardson, Hazel. Smithsonian Handbooks: Dinosaurs and Prehistoric Life. New York: Dorling Kindersley, 2003.
Sereno PC, Myhrvold N, Henderson DM, Fish FE, Vidal D, Baumgart SL, Keillor TM, Formoso KK, Conroy LL. “Spinosaurus is Not an Aquatic Dinosaur.” Elife. 2022 Nov 30;11:e80092. doi: 10.7554/eLife.80092. PMID: 36448670; PMCID: PMC9711522.
Smith, Nathan D., Peter J. Makovicky1, Federico L. Agnolin, Martin D. Ezcurra, Diego F. Pais3 and Steven W. Salisbury. “A Megaraptor -like theropod (Dinosauria: Tetanurae) in Australia: support for faunal exchange across eastern and western Gondwana in the Mid-Cretaceous.” Proceedings of the Royal Society. 20 May 2008.
“Sue at the Field Museum.” The Field Museum, Chicago, IL. 2007. 15 July 2009.
University of Queensland. “Australian Dinosaur Found To Have South American Heritage.” ScienceDaily 15 June 2008. 10 September 2009 <http://www.sciencedaily.com /releases/2008/06/080613111410.htm>.
Tyrannosaurus rex, long considered the largest carnivorous dinosaur, faces competition from newer discoveries.
The name Tyrannosaurus rex means “king of the tyrant lizards,” but a number of other giant carnivores would like to steal its crown. Recently some pretty big, fierce dinosaurs have been found.
Tyrannosaurus Nobu Tamura, CC BY-SA 4.0, via Wikimedia Commons
From its discovery in 1902 until the 1990s, Tyrannosaurus rex was regarded as the biggest, most powerful carnivorous dinosaur of all. It was about 40-42 feet long, stood about 12-15 feet tall at the hip, and weighed about 9.7 tons. These days, however, there are at least four other contenders for that crown. Two are from Argentina and two are from Africa. Today, I’m going to write about the two from Argentina, and in two weeks, the two from Africa.
Giganotosaurus (GIG-ah-noh-ta-SAWR-us). was found in Argentina in 1993. Its name comes from Greek words meaning “giant southern lizard.” There’s a lot of confusion about how to pronounce its name. It is definitely not said like gigantic. That leaves out the first “o” in its name. In Greek, the “g” is a hard sound, like get. So that’s what I go with. Lots of Internet sources use a “j” sound, making it JIG-ah-noh-ta-SAWR-us. But I have to go with the Greek sound: GIG-ah-noh-ta-SAWR-us.
When it was first discovered, paleontologists thought Giganotosaurus was an impressive eight feet bigger than T-rex. Now most think they were similar in size, though Giganotosaurus was probably a little longer, about 40-423 feet long. Their heights and weights also seem to have been similar, with Giganotosaurus having just a slight edge.
T-rex did have some advantages. Its teeth, which were likely used as weapons, could reach 12 inches long, but those of Giganotosaurus were only 8 inches (as if eight-inch teeth were small!). Even more importantly, T-rex had a bigger brain, with well-developed optical lobes, helping it see better. Giganotosaurus had smaller optical lobes, but bigger lobes devoted to smell. Which do you think is more important to a hunter: sight or smell?
These two certainly would have had a huge battle if they ever met. But that never happened. Giganotosaurus lived about 99.5 to 95 million years ago in the area that is now Argentina in South America. Tyrannosaurus lived 72.7 to 66 million years ago in what is now the western United States.
Giganotosaurus ДиБгд, Public domain, via Wikimedia Commons
The other contender from Argentina is Megaraptor (MEG-uh-rap-tor). Its name means “large thief.” Megaraptor is known from just a few partial skeletons found in Argentina and Australia in 1997. It lived about 75 to 92 million years ago. Scientists think it might have been about the same height as T-rex. Megaraptor was about 13 feet tall at the hip, but it was not nearly as long, only about 25 to 33 feet, 7-9 feet shorter than Tyrannosaurus.
Megaraptor skeleton Kabacchi, CC BY 2.0, via Wikimedia Commons
It would seem that Tyrannosaurus’ larger size and probably greater strength would scare Megaraptor off before the fight even began, but that’s not the whole story. What Megaraptor did have was a 15-inch claw on the first finger of each of its hands – and its other claws were pretty big, too. That first claw, though, is almost twice the length of the longest T-rex claw. Tyrannosaurus’s tiny arms were pretty useless in a fight. Megaraptor could use its longer, muscular arms and huge hands to reach in and slash its prey. Also, Megaraptor’s lighter build probably made it faster than T-rex and more agile. It could dart in and out quickly to avoid Tyrannosaurus.
So, it would be an epic battle. Who do you think would win? Could either of these two take Tyrannosaurus’ crown? Or does that crown belong to a dinosaur from Africa? Come back in two weeks to find out.
Sources (Click Me!)
Calvo, Jorge Orlando and Rodolfo Coria. “New Specimen of GiganotosaurusCarolini (Coria & Salgado, 1995), Supports it as the Largest Theropod Ever Found.” GAIA, Lisbon, December 1998.
Currie, Philip J and Colleayn O. Mastin. The Newest and Coolest Dinosaurs. Grasshopper Books Publishing, 1998.
Frachtenberg, Fabio, and Jorge Calvo, Oscar A. Frachtenberg. Dinosaurios Argentinos: Giants of Patagonia. Aurora, IL: SciTech Hands-On Museum, 2006.
Gasparini, Zulma, Leonardo Salgado, and Rodolfo A. Coria (eds.). Patagonian Mesozoic Reptiles. Indiana University Press, 2007.
Larson, Peter and Kenneth Carpenter. Tyrannosaurus Rex: The Tyrant King. Indianapolis: Indiana University Press, 2008.
Mazzetta, Gerardo V., Per Christiansen, and Richard Farina. “Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs.” Historical Biology, June – December 2004, Vol. 16 (2-4) pp. 71-83.
Miller, Erin. “T-Rex’s older, tougher cousin – Giganotosaurus skeleton will go on national tour.”Daily Telegraph, The (Sydney) (n.d.). Newspaper Source_. EBSCO. Judson University Library, Elgin, IL 15 JJuly 2009. <http://www.judsonu.edu:2048/login? url=http://<http://www.judsonu.edu:2048/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=nfh&AN=200312221022639124&site=ehost-live>.
Novas, Fernando, E., Diego Pol Juan I. Canale; Juan D. Porfiri; Jorge O. Calvo. “A Bizarre Cretaceous Theropod Dinosaur from Patagonia and the Evolution of Gondwanan Deomaeosaurids. Proceedings: Biological Sciences, Mar2009, Vol. 276, Issue 1659, p1101-1107.
Porfiri, Juan D., Domenica Dos Santos, and Jorge O. Calvo. “New Information on Megaraptornamunhuaiquii (Theropoda: Tetanurae), Patagonia: Considerations on Paleoecological Aspects.” Arquivos do Museu Nacional, Rio de Janeiro, 2007, Vol. 65, n. 4, pp. 545-550.
Richardson, Hazel. Smithsonian Handbooks: Dinosaurs and Prehistoric Life. Dorling Kindersley, 2003.
Smith, Nathan D., Peter J. Makovicky1, Federico L. Agnolin, Martin D. Ezcurra, Diego F. Pais3 and Steven W. Salisbury. “A Megaraptor-like theropod (Dinosauria: Tetanurae) in Australia: Support for Faunal Exchange across Eastern and Western Gondwana in the Mid-Cretaceous.” Proceedings of the Royal Society. 20 May 2008.
Spotts, Peter N. “Giant Dinosaur Fossil Forces Scientists to Question Theories.” Christian Science Monitor 03 Dec. 1997: 3. Academic Search Premier. EBSCO. Judson University Library, Elgin, IL. 15 July 2009. <http://www.judsonu.edu:2048/login?url=http://search. ebscohost. com/login.aspx?direct=true&db=aph&AN=9712050418&site=ehost-live>.
University of Queensland. “Australian Dinosaur Found to Have South American Heritage.” ScienceDaily. 15 June 2008. <http://www.sciencedaily.com/releases/ 2008/06/080613111410.htm>.
Thank you for reading my blog! I’m sorry not to have posted anything for so long. My mom got sick and passed away. I’m trying to get back on track again and plan to post something every other week. I hope you enjoy this week’s blog.
For decades after dinosaurs were discovered, people thought they were just big, dumb, plodding animals. One of the discoveries that helped convince scientists that there was much more to dinosaurs than that was the discovery of Maiasaura.
Maiasaura Nest Model Fernando Losada Rodríguez, CC BY-SA 4.0, via Wikimedia Commons
In 1978, paleontologist, Jack Horner, discovered a field of dinosaur nests in Montana. The nests not only had unhatched dinosaur eggs but also skeletons of baby dinosaurs. The babies were not newborns. They were too big to have just hatched. That meant they were living in the nest — which meant the mother dinosaurs were taking care of the babies! If the babies had to feed themselves, they would have wandered away from the nest. This was an amazing idea at the time. No one thought dinosaurs were smart enough to take care of their babies. Horner named the dinosaur Maiasaura, which means “good mother lizard.”
In many ways, Maiasaura was just an average dinosaur, which makes their caretaking even more interesting. It is one of the duckbilled dinosaurs. Duckbilled is a nickname given to several different types of dinosaurs that had mouths shaped like a duck’s bill. The Maiasaura didn’t have any teeth in the front of its long, flat mouth, but in its cheeks, it had hundreds of them.
T-Rex Taylor, Public domain, via Wikimedia Commons
Many duckbilled dinosaurs had fancy crests on their heads, but the Maiasaura’s head was flat, with just a very short, bony spike above its eyes. Some scientists think the Maiasaura might have had a flap of skin, like the comb of a rooster, attached to the spike. Male Maiasauras could have used that to attract the attention of female Maiasauras.
A Maiasaura was about the size of a camping trailer. That may sound big, but it was only average for a dinosaur. Most adult Maiasauras grew about 20 feet long. They stood about 15 feet high and weighed about two-and-a-half tons.
Maiasauras walked on all four legs much of the time, but they could walk on just their two back legs if they needed to. Their front legs were smaller and thinner than their back legs and had four fingers.
Pavel.Riha.CB, CC BY-SA 3.0, via Wikimedia Commons
The Maiasaura was a plant-eating dinosaur. It ate tree needles, twigs, seeds and berries. As you might expect, chewing these tough, woody foods wore its teeth down. But the Maiasaura had an easy way to avoid the dentist. It had teeth stacked inside its jaws, one on top of the other. Whenever a tooth wore out, it just fell out and was replaced by the one underneath.
All dinosaurs hatched from eggs. The Maiasaura laid her eggs in bowl-shaped nests. As you might guess, these big creatures needed BIG nests – about six-feet wide! Scientists think the mothers used their powerful back legs to make a huge mound of dirt on a flat area and used their arms to hollow out the center. Many Maiasauras made their nests in the same area, keeping them about 23 feet apart. That allowed the mothers space to walk between the nests without stepping on anyone else’s nest. The mothers probably brought plants to the nest to cover the eggs to keep them warm. If they had sat on them, they would have squashed them!
The babies were about 14 inches long when they were born – about the size of one of their mother’s feet. Each weighed only three or four pounds. The mother brought food to the nest, just as a mother bird will do today. We know the babies stayed at least part of the time in the nest because the shells in the nest were broken into tiny pieces as if walked over many times. Some of the baby skeletons Horner found in the nests were about three feet long. It probably took them several months to grow that big, so an adult must have not only brought them food all that time, but also guarded them from meat-eating dinosaurs looking for a snack.
Debivort, CC BY-SA 3.0, via Wikimedia Commons
When the babies were big enough, they joined a herd. Huge herds of Maiasauras roamed the upper coastal plains – as many as 10,000 in a single herd! This was their best defense against predators. Meat eaters would have to look for a single dinosaur that became separated from the herd. Maiasauras had good hearing and good eyesight, so they could be aware of danger. They would eat all the plants in one place and then move on to another. Scientists think they may have traveled a regular route, always returning to the same nesting ground when it was time to lay their eggs.
Over the years many paleontologists have returned to what they call “Egg Mountain” in Montana to study the bones, eggs, and nests fossilized there. The more they learn, the more amazing this “good mother” dinosaur seems.
Ever wonder how the Brontosaurus lost its name? Commonly known as the icon of Sinclair Oil, this sauropod’s history is complex and newsworthy.
The Brontosaurus is one of the most famous dinosaurs in the world. Millions of people know its name. Most can recognize its huge shape. It’s been on lunch boxes, made into countless toys, and was featured on a U.S. postage stamp. It even served as the official icon of Sinclair Oil company. However, there is one problem: there is no dinosaur named Brontosaurus.
How did this happen? When dinosaurs were first discovered in the 1820s, the idea of those huge reptiles stalking the earth caught people’s imagination. Every museum in the world wanted to display a huge skeleton of a dinosaur. But it takes many years to find dinosaur bones, dig them up and put together a dinosaur skeleton. Over the next sixty years the competition to discover dinosaur bones grew, and then it became especially fierce during the 1880s. In fact, that time is now known as the “Bone War.”
From 1877 to 1892, two paleontologists in particular, Edward Cope of the Academy of Natural Sciences in Philadelphia and Othniel C. Marsh of the Peabody Museum in Connecticut, were the fiercest competitors. They used their own money to finance expeditions and to buy dinosaur bones from other fossil hunters.
In the beginning Cope and Marsh just paid collectors to send them fossils. But this was only the start. As the rivalry intensified, each side spied on the other, stole bones when they could, bribed workers, and even blew up fossils with dynamite so that the other side couldn’t get them. As soon as either dinosaur hunter got new bones, he rushed to get a description into print. Whoever publishes a description of a new dinosaur first gets to name it, and each man wanted to be the one to name the most. In the end Cope lost. He named 56 new dinosaur species, while Marsh named 80. And by the end of the Bone Wars in 1892, both men had gone nearly bankrupt trying to be the best (or most famous) paleontologist. And the hurry of both men led to mistakes.
Tadek Kurpaski from London, Poland, CC BY 2.0, via Wikimedia Commons
In 1877 Marsh published a papernaming a new dinosaur, Apatosaurus ajax. Its name means “deceptive lizard,” which turned out to be the truth. The description was based on only a few bones. Two years later Marsh published another article describing what he thought was a different dinosaur, Brontosaurus excelsius. This description was based on one of the most complete skeletons of a long-necked dinosaur ever found. Brontosaurus means “thunder lizard,” and the catchy name became popular. The mount of that Brontosaurus skeleton in the Yale Peabody Museum of Natural History increased its popularity. Unfortunately, one of the missing pieces of the skeleton was its skull. Not to worry. Marsh just put a Camarasaurus skull on it.
But, in 1903, Chicago paleontologist Elmer Riggs took a look at both dinosaurs. He determined that the two dinosaurs were actually the same dinosaur. It was given the name Apatosaurus first, and the International Code of Zoological Nomenclature states that the oldest name has priority, so that is the name used by scientists. Brontosaurus became Apatosaurus. And in 1979 scientists finally put the right skull on the skeleton. Still, the general public didn’t let go of the name Brontosaurus until about the 1990s. It was just too cool a name to let go.
However, all is not lost. There is a movement to resurrect the name Brontosaurus. In 2015 paleontologists studied hundreds of bones from Apatosaurus and the dinosaur called Brontosaurus and found differences in the neck, back, and shoulder bones. Originally scientists thought those difference were because one of the dinosaurs was a juvenile. Now some feel these differences are enough to say Brontosaurus and Apatosaurus are different dinosaurs. But this has not gained wide acceptance. More research may resolve the problem. But a lot of people who are just dinosaur lovers would welcome the return of the “thunder lizard.”
Cover Image Source: An Errant Knight, CC BY-SA 4.0, via Wikimedia Commons
Two hundred years ago, the word “dinosaur” didn’t exist. It didn’t need to. No one knew that giant reptiles had once walked the earth.
Occasionally people found large bones, but they usually thought they belonged to some animal, like an elephant or a giraffe. One piece of bone was thought to have been from a race of giant people. Dinosaur bones may even be responsible for the belief in dragons in ancient China. Then, in England, two gentlemen working separately discovered dinosaurs at about the same time.
The first was Dr. Gideon Mantell, a physician and amateur geologist. In 1822 his wife, Mary Ann Mantell, found some very large, unusual teeth in a pile of gravel. Mantell sent the teeth to other experts, but they dismissed them as belonging to a known animal. One paleontologist said they were from a rhinoceros. Mantell didn’t give up. He was sure the teeth were something special. He learned that the pile of gravel his wife had found the fossils in came from a nearby stone quarry. There he found more teeth and some bones. After much study, he determined that the bones and teeth came from a giant reptile. The teeth resembled those of the iguana lizard, but they were twenty times bigger!
Illustration of the original Iguanodon teeth found by Mantell Gideon Mantell, Public domain, via Wikimedia Commons
In 1825, Mantell published a description of the creature, describing it as being at least 40 feet long. He named it Iguanodon (eh-GWA-nuh-don), Iguana from the iguana lizard and don, meaning tooth.
Meanwhile, in 1824, the Rev. William Buckland of Oxford came into the possession of some bones, including part of a jaw with teeth.
Mary Buckland, née Morland (1797-1857), Public domain, via Wikimedia Commons
These teeth were clearly those of a giant reptile. Buckland named it Megalosaurus (MEH·guh·luh·sore·us), which means “great lizard.” He published a description of it that same year, which means it was the first dinosaur described scientifically. Mantell was still struggling with skeptics, and, as I said above, he didn’t publish until 1825. But, in 1833, Mantell discovered another giant reptile, Hylaeosaurus (hy-LEE-oh-sore-us). Hylaeosaurus was an armored, plant-eating dinosaur that grew about 16 feet long. So he discovered two of the first three dinosaurs.
A scientist named Sir Richard Owen was the one who put it all together. He studied the bones and teeth of all three creatures. He found them to share some characteristics, such as fused vertebrae at the base of the spine. But he found them quite unlike modern reptiles. He determined that these three animals deserved their own category. In 1842, he invented the name dinosaurs, which means “terrible lizards,” to describe them.
People were excited about these huge creatures and wanted to know what they looked like. Scientists tried to figure out how to put together the bones that had been found. But it was like trying to put together a jigsaw puzzle with only half the pieces. They thought Iguanodon looked something like a fat rhinoceros. In 1852, a sculptor named Waterhouse Hawkins made life-sized models of what scientists thought Iguanodon and Megalosaurus looked like.
Statues of Iguanadon and Megalodon Jes from Melbourne, Australia, CC BY-SA 2.0, via Wikimedia Commons
He and the scientists made a lot of mistakes. For example, when they found a spike from the Iguanodon, they put it on its nose. It was really the creature’s thumb. But they didn’t know they’d made so many mistakes. In fact, they were anxious to show the world their dinosaurs. When the model was half done, they decided to have a dinner party – in the dinosaur!
Public domain, via Wikimedia Commons
Many important scientists were invited. The seating area was a bit crowded, but everyone had a wonderful time. This was probably the only time in history that a dinner was inside a dinosaur without being the dinosaur’s dinner!
Since that time, we’ve learned so much more about dinosaurs, including more about how Iguanodon and Megalosaurus looked. They stood with all four legs directly under their bodies and didn’t drag their tails. They were active, not slow, sluggish creatures. But the excitement people felt then is the same excitement people still feel today.
The best part of any museum is the dinosaurs– especially the huge skeletons! But they didn’t just walk into the museum on their own. And those bones weren’t always clean and perfectly shaped.
In fact, the bones fossil hunters dig up are usually damaged in some way. They might have been chewed on by predators or scattered about by wind or water. They can be cracked, split, or smashed. So how do they go from broken to beautiful? This happens in a fossil lab.
It starts with getting the bones safely back to the fossil lab. When a bone is dug out of the ground, sometimes it comes free easily. But more often the bone is attached to the rock, so fossil hunters need to carve out both. They use jackhammers and rock saws, pickaxes, hammers, and chisels.
Scientists call the rock next to the bone the matrix. Fossil hunters leave the matrix around the bone, so it can protect the bone. They cover the bone and its matrix with plaster to provide more protection. The whole thing can weigh several hundred pounds.
Small bones are packaged in crates while big bones may be lifted out by helicopter. They are all sent to a fossil lab. Unloading the bones must be done carefully. The big bones don’t always fit through the door. They need to come in through a loading dock.
Some bones are stored away. There are always more bones needing preparation than time and people to prepare them. Bones not being worked on are put on shelves or in specimen cabinets.
Other bones are brought into the prep lab to have the matrix removed from the bone. The workroom needs to have bright lights, so preparers can see what is rock and what is bone. It also needs good air flow because removing the matrix produces a lot of dust. Stations are set up around the room.
A work station needs to have a large, flat surface to place the fossil on. There should be storage space for the tools the preparer will need and its own light source. It may also have a microscope to study small fossils and an air tube to vacuum up the dust and tiny bits of rock. The preparer should wear protective goggles, a dust mask, and gloves. Preparers using noisy tools, such as a jackhammer, also need ear plugs.
When a bone is selected for preparation, first the preparers need to remove the plaster jacket. They use a cast-cutting saw, like the ones doctors use to remove a cast from a broken limb. A preparer might then use a small jackhammer called an air scribe to remove the matrix that is not too close to the bone.
When preparers get close to the bone, they need to be very careful. The bones break very easily. Using a small metal pick called a pin vise (pictured to the side), preparers scrape away the rock, just like when a dentist scrapes plaque from your teeth. They scrape in a direction away from the bone so that if they slip, they don’t hurt the bone. The key is to go slowly. Sometimes they use a magnifying glass to make sure they are scraping away only the matrix.
Bits of matrix are blown away with an air tube as they come off. Brushes can also be used to keep the surface clean, and a very sharp needle might be used to remove matrix in small cracks. Exposed bone is covered with glue to keep it from breaking apart.
Sometimes preparers use chemicals, such as acid, to dissolve the matrix, but they must be careful to make sure the chemicals don’t hurt the bone. It can take anywhere from a few minutes to hundreds of hours to remove all the matrix. Sometimes part of the matrix is left to hold delicate bones together.
Once the matrix is removed, there is still work to be done. Often the bone is broken, so the pieces must be put together. That can be like putting a jigsaw puzzle together. Very small bones can be kept together with wax. Others need glue, and others need wire or steel bands.
Putting together all the bones of a skeleton takes lots of patience. Preparers make sketches and 3-D models. Bones need to be placed next to each other in the same way they were when the dinosaur was alive. A natural-looking pose must be chosen.
It is rare that fossil hunters find all the bones for one dinosaur. Preparers need to figure out which bones are missing. To complete the skeleton, preparers may use bones from several dinosaurs of the same species. Sometimes they can figure out what a bone should look like by the bones around it. Then preparers can sculpt a bone from plaster or plastics.
Many of the prepared bones are stored in cabinets or lockers. They each have a number that tells when and where the fossil was found. Scientists can find the fossil they need and study it.
Sometimes the scientists make a cast of a bone. First, they make a rubber mold from the real bone. Then they put plaster or resin into the mold. When it dries, it’s a perfect copy. Museums often display casts rather than the real bones. This prevents damage to the real bones and makes it easier for scientists to study the real bones. Casts are also used to make model dinosaurs. Artists create realistic-looking dinosaurs for the movies or special exhibits. However, technology is already making this process easier and faster by using 3-D printing. In the future plaster casts will be a thing of the past.
To prepare a skeleton for an exhibit, it’s important for preparers to make sure every bone is stable. Fossils are very heavy, so the framework holding them up needs to be able to hold the weight without hurting the fragile fossils.
The bones are held together with such things as glue, metal pegs, bolts, wire, and thick cables. The preparers try to keep these out of sight because they want the dinosaur to look as natural as possible.
It can take several years to mount a big dinosaur. But when it’s all done, thousands and thousands of people will gaze up at the dinosaur skeleton and catch their breath with awe.
Would you like to work in a fossil lab? Please tell me why or why not in the comments section.
I know the ‘Facts Tier List’ is something that has been done to death in pop-culture. But I thought it would be fun to make a short list of the most obscure facts I could find about the king lizard, Tyrannosaurus Rex. If this is something you find interesting, I may make this a series where we cover less recognizable dinos!
1/3 |T-Rex wasn’t Always The Most Popular
Taking a look at the countless pictures, books, movies, and exhibits on the world of paleontology, it is self-evident that the Tyrannosaurus Rex is one of, if not the most popular dinosaur. Many would assume that this has always been the case, but what if I told you that wasn’t.
My older readers may recognize the name or shape of the Brontosaurus. A sauropod with a complicated history, this dinosaur was the symbol for Sinclair Oil and at one time was considered the face of the dinosaur world. The Brontosaurs will be the topic of a future post, so subscribe so you don’t miss out!
2/3 | Usable Arms
The T-Rex is often made fun of for it’s tiny arms. They were quite small in proportion to the rest of its body, measuring in at only 2-3 feet. The T-Rex’s head alone was 5 feet long. However, just because they were tiny, doesn’t mean they were useless. Their arms were incredibly capable despite the size and were able to support over 400 pounds in weight.
There is still speculation as to what purpose their arms served. Many believe they were used to help T-Rex lift itself off of the floor or for holding on to recently killed prey.
Although the T-Rex has earned the moniker: ‘King of the Dinosaurs’, that doesn’t mean that T-Rex was the largest Carnivore of them all. T-Rex was estimated to be about 40 feet long and weighed between 7 and 9 tons. The Giganotosaurus and the Spinosaurus both outclassed the king lizard, with the former weighing 9 tons and the latter weighing over 10 tons. Giganotosaurus barely beats out T-Rex in length, as it was recorded to be 43 feet long. But the Spinosaurus takes the cake at almost 60 feet long from head to tail! I may take a deeper look into the unique features of these 3 species…
I hope you found these facts interesting; I surely did! If there are any facts you would like to share, feel free to do so in the comments below.
In 1868, the hottest ticket in town was to the Philadelphia Academy of Natural Sciences. Before that year about 30,000 people visited the museum annually. But in 1868, attendance more than doubled to 66,000. The next year it soared to 100,000. What was it that people stood in line for hours to see? The first complete dinosaur skeleton ever displayed to the public: Hadrosaurus. People stared in awe. It was three stories tall! Philadelphia had to build a bigger museum to have room for the crowds.
Hadrosaurus was found in New Jersey in 1858. And at that time, it was the most complete dinosaur skeleton that had ever been found in the whole world.
What do we know about it today? It was just an average duckbill dinosaur. It didn’t even have a crazy crest like some duckbill dinosaurs. Its head was flat.
It grew about 23-26 feet long and could have weighed 2-4 tons. Its back legs were much longer than its front legs. It could walk on just its hind legs or on all four legs. The front of its mouth was a beak, covered in keratin, just like your fingernails. This helped it nip off plants, which it ground up with its large teeth. It traveled in herds.
The original pose was upright. But we now think it probably stood like this, with the tail balancing the head:
When it was first displayed almost everyone was thrilled to see it – but that’s almost. A copy of Hadrosaurus was made and was supposed to go on display in 1871 in New York City. But it never did. One of the most powerful men in New York in that day, William Tweed, known as Boss Tweed, ordered members of his gang to destroy the skeleton. No one knows why. They tore it apart and tossed the pieces of it into a nearby lake.
Today Hadrosaurus doesn’t cause any controversy. People know it as just an average dinosaur. But New Jersey is proud that it is its state dinosaur, and people still flock to see it.
Can you draw a duckbill dinosaur head with a crazy crest? Please put one in the comment section or message me on Facebook at Janet Riehecky
To learn more about dinosaurs, please visit here once a week. Please also visit my web site: www.janetriehecky.com
It’s almost impossible to declare that one dinosaur was the biggest of them all. Do you mean longest, heaviest, or tallest? Also, it’s very unlikely that paleontologists have actually found the biggest specimen of a dinosaur type. Millions and millions of dinosaurs once lived on Earth, and we’ve found only a small percent of them. We do know that all of the biggest dinosaurs are plant eaters. They come from the group of dinosaurs called sauropods, the long-necked dinosaurs – and most of the very biggest ones have been found in Argentina.
So, how do paleontologists figure out how long or tall a dinosaur was? They need to look at the spine. Put your fingers on the back of your neck. The little bones you feel there that are part of your spine are called vertebrae. When a dinosaur skeleton is found, usually many of the vertebrae are missing. When there is a gap, paleontologists have to guess how many are missing. One way they do this is by comparing the bones they have to other, similar dinosaurs. If a similar dinosaur had, say, 80 vertebrae in its tail, paleontologists would assume that a closely related dinosaur had 80, too. But that might not be true. And it’s hard to know how big those missing vertebrae would be. Scientists have to make the best estimate they can, but they often don’t agree with one another. However, they have provided some great contenders for biggest dinosaur!
This might be Barosaurus (BARE-uh-sore-us). It was discovered in 1889 in South Dakota. Its name means slow, heavy lizard, and it must have been. Scientists think it was probably 82-89 feet long. That’s long, but that’s not what put it in contention for longest. Scientists have found a huge vertebra that they think belonged to Barosaurus. From the size of it, the creature it came from was likely about 157 feet long! That’s almost as long as three eighteen-wheeler trucks set end to end.
Another contender is Argentinosaurus (are-juhn-tee-nuh-SORE-us). Scientists have only found 13 of its bones: a few ribs, some vertebrae, and a five-foot-long femur (thigh bone). This isn’t much to try to figure out how big this dinosaur was, but the sizes of those bones have led scientists to estimate that Argentinosaurus was between 75 and 100 feet long. If that top limit is right, Argentinosaurus is definitely among the very biggest dinosaurs.
Argentinosaurus is also a contender for the heaviest dinosaur, but because estimates of its weight are based on so few bones, some scientists discount it. However, paleontologists have unearthed more than 200 bones of Patagotitan (PAT-ah-go-TIE-ton). These bones were found in Argentina in 2012 and cause scientists to estimate that it weighed about 76 tons. The largest land animal today is the African elephant. Its top weight is seven tons. That means that Patagotitan weighed nearly as much as 11 elephants. And some scientists think at its biggest it weighed as much as 14 elephants.
Dreadnoughtus (dred-NOHR-tus) is a definite contender in weight. Its name means fearing nothing. And it’s hard to imagine any creature that it would have to be afraid of. It was discovered in Argentina in 2005. Scientists have recovered almost half of its bones, so they are able to be fairly accurate in their estimates. They place its weight between 54 and 65 tons (though some scientists say that’s too high). It was also about 85 feet long and as tall as a two-story building.
Two stories, however, is not a contender for height. The tallest dinosaurs reached close to the height of a six-story building, though again, it’s tricky to know for sure. Scientists don’t agree on how high up long-necked dinosaurs could lift their heads. Sauroposeidon (Sore-uh-ps-SY-don) is certainly one of the tallest. It was found in Oklahoma in 1994 and named for the Greek god Poseidon. Poseidon could cause earthquakes, and it probably felt like this dinosaur could do that, too – just by walking. It probably stood just over 55 feet tall, which is, as it says above, almost the height of a six-story building.
Patagotitan shows up again here. Depending on how it carried its long neck, it might have been as tall as a seven-story building. If it carried its head and neck low to the ground, straight out from its body, it’s a contender for longest dinosaur at 122-130 feet. The picture at the right shows Patagotitan at the Field Museum in Chicago
Scientist do not agree which one was the biggest dinosaur. Other lists would include such dinosaurs as Mamenchisaurus (mah-MUN-chi-SORE-us), a creature whose neck was longer than the rest of its body, or Giraffatitan (ji-RAF-ah-TIE-tan), which had the same general build as a gigantic giraffe. We may never know which dinosaur was the biggest. But we can all agree that they were awesome!
Which dinosaur do you vote for as biggest? Do you know a big dinosaur that isn’t in this list? Please leave your answers in the comment section.
Hope everyone is adjusting to the fall nicely! Here are a few dinosaur jokes that made me chuckle. Feel free to post your own jokes in the comments down below.
Not very long ago paleontologists were sure of at least one thing about dinosaurs: nobody would ever know what color they were – unless somebody invented a time machine. Artists had to make up the colors because there were only bones to work with. And you can’t tell the color of anything’s skin from looking at its bones. Even the discovery of several dinosaur “mummies” didn’t help [See my post on dino mummies here]. Though some of these had preserved dinosaur skin, the skin had taken on the color of the minerals that seeped into it to fossilize it. But modern technology has changed this. There are now a couple of ways to determine what color certain dinosaurs were.
The first is a rare case. In 2011 an armored dinosaur called Borealopelta (BOH-ree-AH-low-PEL-tuh) was discovered. Its skin was so well preserved that scientists were able to use a mass spectrometer to discover its color. How does that work? A mass spectrometer is able to tell the chemical substances something is made of, and when you know the exact chemical substances, and where they are, you know what color it is. In the case of Borealopelta, scientists determined the dinosaur was dark reddish brown on the back and neck and lighter reddish brown on the belly and lower parts.
But finding such well-preserved skin is rare. However, scientists have found another way to determine color. Using an electron microscope they found tiny structures that were smaller than cells. At first these were dismissed as bacteria, but they were, in fact, melanosomes (muh-LAN-uh-sohmz), irregular blobs that contain color pigments. Melanosomes can be found in skin, hair, scales or feathers. The size, shape, thickness, and dispersal of melanosomes found in a fossilized feather can be compared to those found in modern birds to determine a color. Then the trick is finding dinosaur fossils that contain preserved skin, hair, scales, or feathers. So far, feathers have been the main structure to reveal dinosaur color through melanosomes.
In 2009 scientists found a feathered dinosaur, which they named Anchiornis (ANG-kee-OR-niss). It lived during the late Jurassic Period. The fossil included some preserved feathers, which were examined under an electron microscope. Analysis of the melanosomes indicated this was a black-and-white dinosaur with a patch of red on the back of its head.
Other dinosaurs have been colorized by this same process. A recent discovery in China, Caihong (KAY-hong), was found with remains of actual feathers. When these were analyzed, they showed that most of the dinosaur was iridescent black, a glossy black that subtly changed its hue when looked at from different angles. The head, chest, and the base of the tail contained melanosomes that produce bright iridescent colors in modern birds. These colors could not be specifically identified, but artists have guessed at what they might be.
Other dinosaurs that have been colorized include Sinosauropteryx (SIEN-oh-soh-ROP-tuh-riks) – which lived during the early Cretaceous Period and had bright orangish feathers with a lighter belly and a striped tail.
And they include Microraptor – a small meat-eating dinosaur that also lived during the early Cretaceous Period and had feathers that gleamed an iridescent blue/black, like ravens or starlings.
As stated earlier, melanosomes can also be found in scales. Psittacosaurus (SIT-a-ko-SOR-us) is an early Cretaceous dinosaur distantly related to Triceratops. It does not have feathers, but one of the skeletons found had preserved scales that contained melanosomes. They revealed the dinosaur was dark brown on its back and a paler brown on its underside with its hind legs being striped on the inside and spotted on the outside.
Melanosomes are not the answer to the color of every dinosaur. There has to be preserved soft tissue to have melanosomes, and most fossils lack that. Additionally, some colors, such as blues and yellows, are not made by melanosomes. Still, even knowing the colors of a few dinosaurs is something most scientists once thought would never happen.
What color do you think Tyrannosaurus rex was? Put your guesses in the comment section.
As we transition into the fall, I thought it would be fun to reminisce on one of my favorite summer vacations.
One of the best adventures of my life occurred one summer when my family and I spent a week in western Colorado. During two of those days, we joined a dinosaur dig. It was very hot and dirty. Insects swarmed us, the nearest porta-potty was a half mile away – and I never had more fun in my life!
The paleontologist in charge of the dig, Jim Kirkland, told us where to dig and what to do. The area we dug in was a vast bone bed dating to about 150 million years ago, during the late Jurassic (one of the three time periods during which dinosaurs lived). Many dinosaurs had died, perhaps in a flood, and had their bodies swept into this huge heap. Their bones were all jumbled together. Diggers in that area have found bones from Brachiosaurus, Stegosaurus, Allosaurus, Apatosaurus, and other Jurassic dinosaurs. We would not get to keep any bones we found. They would stay with the paleontologists for study, as they should.
The rock was crumbly, like flaky pastry, and easily removed with just our hands. We searched through it and then discarded the rock into plastic bins. It’s not always easy to tell what’s rock and what’s bone, but at this site the rock was a light brown and the bones much darker brown, almost black. We moved a lot of rock before we saw anything. (Caption: That’s my husband, John, in striped shirt, my son, Patrick, in red cap, and Jim Kirkland in cowboy hat.)
That thrill, though, when you see a bone that’s been buried for 150 million years is not like anything else. It was definitely worth the hours of digging. I felt awed and elated and also a little humble. I’m a tiny speck in this universe. You know, we also spent two days white water rafting while we were in Colorado, but digging up dinosaur bones was more exhilarating!
During those two days digging I only found three bones, but one of them in particular interested Dr. Kirkland (in red shirt at left; me in blue). It looked like a piece of armor from an armored dinosaur, but at that point no one had ever found an armored dinosaur in Jurassic rock. Further excavation after I left produced more of that dinosaur, and it turned out to be just what Dr. Kirkland suspected: an armored dinosaur, the first ever found from the Jurassic Period. He named it Mymoorapelta and wrote to me about it. He also put out a press release, and I got my picture on the front page of the local newspaper!
Dr. Kirkland is now the state paleontologist of Utah.
Mymoorapelta is a nodosaur, which means, among other things, that it doesn’t have a club at the end of its tail. It was one of the earliest armored dinosaurs ever to have lived, and, at 9.8 feet long, one of the smallest. It ate mostly plants that grew low to the ground, such as ferns, cycads, and conifers. Its teeth were small and leaf-shaped. Scientists can’t say for sure, but it is likely that it lived in herds.
I will leave you with this question: If you found a new dinosaur, what would you name it? Please let me know in the comment section.
I don’t know who makes up the names for groups of animals: a herd of cows, a pack of wolves, or a litter of kittens. Some of the group names are funny: a business of ferrets, a kettle of hawks, a bloat of hippopotami, a shiver of sharks, a stench of skunks, and an ambush of tigers. But whoever makes up those names certainly got it right for Tyrannosaurus. A group of them is called a terror of tyrannosaurs. Several species of dinosaur fall into the category of tyrannosaur, such as Albertosaurus, Gorgosaurus, and Daspletosaurus. The most famous, of course, is Tyrannosaurus rex. All of them are among the largest meat-eating creatures that ever lived.
Scientists don’t know whether or not Tyrannosaurus lived or travelled in groups. There are only two clues that could help with this. Sometimes paleontologists find bonebeds that contain many dinosaurs of the same kind that all died at the same time. That might happen if a flash flood killed a large herd of animals. For example, in Alberta, Canada, thousands of bones of the dinosaur Centrosaurus were found in a bonebed measuring about 1 ½ square miles. This is strong evidence that centrosaurs travelled in large groups. Dinosaur bonebeds for Protoceratops, Avimimus, Pinacosaurus, Edmontosaurus, and others have been found. But no bonebeds of Tyrannosaurus or any other tyrannosaur have ever been discovered.
The other evidence of animals living or travelling in groups is footprints. Often just one, single footprint is found. Other times a trackway is found, showing the progress of a single dinosaur.
Sometimes there are many footprints, showing the travels of a whole herd. Prior to 2011, only single footprints of tyrannosaurs had been found. Though it’s hard to say for sure which made a footprint, scientists can make educated guesses. The one most confidently attributed to Tyrannosaurus rex was found in Montana in 2007. The Montana footprint was 2 ½ feet long with slender toes, and it was found in the right age of rock for Tyrannosaurus. Also, its toes were correctly positioned for T-rex, so paleontologists are fairly certain they have correctly identified it. But that print doesn’t tell us much about how Tyrannosaurus lived and moved.
Some scientists thought that because they had never found a tyrannosaur bonebed or more than one footprint of a tyrannosaur that Tyrannosaurus was a solitary creature, perhaps only associating with others of its kind for mating. Many of today’s predatory birds, such as eagles and hawks, are largely solitary. That way they don’t have to compete for food. But in 2011 a trackway showing three tyrannosaurs walking together made scientists reconsider the idea of tyrannosaurs as loners.
In the forests of northeastern British Columbia, paleontologists uncovered a series of tracks showing three large dinosaurs walking side by side. A total of seven footprints were found: three from one dinosaur and two from each of the other two, but all the footprints were made at the same time, and they are clearly walking together. The prints are so well preserved that scientists can even see scales on the dinosaurs’ feet. The size of the tracks and the size and positioning of the toes clearly make these tyrannosaur tracks. However, it’s not possible to know which species of tyrannosaur they are from.
McCrea RT, Buckley LG, Farlow JO, Lockley MG, Currie PJ, Matthews NA, et al. (2014) A ‘Terror of Tyrannosaurs’: The First Trackways of Tyrannosaurids and Evidence of Gregariousness and Pathology in Tyrannosauridae. PLoS ONE 9(7): e103613. https://doi.org/10.1371/journal.pone.0103613
The size of the footprints does indicate that the creatures were of a similar age, different scientists estimating perhaps 25, 26, and 29 years old. The size also indicates their approximate height: 7.5 to 9.4 feet tall, measured at the hip. Dinosaur height is usually measured at the hip because most of them didn’t hold their heads at a consistent height. By knowing the height of the animal and measuring how far apart the footprints are, scientists can determine how fast the dinosaurs were going. When scientists did the math for these footprints, they concluded that these three dinosaurs were going 3.9 to 5.2 m.p.h. However, in 2021 researchers from the Netherlands made a computer reconstruction of a Tyrannosaurus walking, and they concluded that its top speed was only about 3 m.p.h. More evidence is needed to figure out how fast a tyrannosaur could walk.
Still the trackways give a tantalizing look at the life of a tyrannosaur, no longer a loner, but a friendly guy who liked to hang out with his terror of friends.
Make up a name for a group of you and your friends. Please put it in the comments below!
Burns, M. E., T. A. Tumanova and Philip J. Currie. “Postcrania of Juvenile Pinacosaurus grangeri (Ornithischia: Ankylosauria) from the Upper Cretaceous Alagteeg Formation, Alag Teeg, Mongolia: Implications for Ontogenetic Allometry in Ankylosaurs.” Journal of Paleontology. 2015. Vol. 89, pp. 168-182. https://pubs.geoscienceworld.org/jpaleontol/ article-abstract/89/1/168/139797/Postcrania-of-juvenile-Pinacosaurus-grangeri.
Evans, D. C., D. A. Eberth, and M. J. Ryan. “Hadrosaurid (Edmontosaurus) Bonebeds from the Horseshoe Canyon Formation (Horsethief Member) at Drumheller, Alberta, Canada: Geology, Preliminary Taphonomy, and Significance.” Canadian Journal of Earth Science. 2015. Vol. 52, pp. 642–654. https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2014-0184?download=true.
McCrea R.T., L.G. Buckley, J.O. Farlow, M.G. Lockley, P.J. Currie, et al. “A ‘Terror of Tyrannosaurs’: The First Trackways of Tyrannosaurids and Evidence of Gregariousness and Pathology in Tyrannosauridae.” 30 July 2014. PLoS ONE Vol. 9, p. 7: e103613. doi:10.1371/ journal.pone.01036
Title Image: Stock photo shows a dinosaur footprint in the ground. Footprints in Texas have been revealed as drought persists. NEENAWAT/GETTY
One of the reasons I like dinosaurs so much is that some of them are just plain weird. And, for me, one of the weirdest is Pachycephalosaurus
(pa-KEE-seh·fuh·luh-SORE-us).
Pachycephalosaurus lived in the late Cretaceous Period, 72 – 66 million years ago, in what is now the western United States and Canada. This was the same time and place that Tyrannosaurus and Triceratops lived. Pachycephalosaurus probably walked on two legs with its tail stretched out behind it and its head leaning forward to balance it. It was about 15 feet long, and weighed almost 1000 pounds. None of that makes it unusual. But when people take a closer look at this dinosaur, it definitely stands out.
Pachycephalosaurus means “thick-headed lizard.” It is a bizarre creature for several reasons. First, the name is weird, even for a dinosaur, because it has so many syllables. If you ever want to impress someone, just rattle off that name without any pauses.
Second, it had nine to ten inches of solid bone in a dome on top of its skull, twenty times thicker than the skulls of most other dinosaurs. That’s a huge difference!
Scientists don’t know for sure why this dinosaur had such a thick skull, but some of them think Pachycephalosaurus liked to butt its head into things, especially other dinosaurs. Head-butting is used by modern animals, such as bighorn sheep or mountain goats, to establish dominance.
The winner controls a territory and impresses the females. The thick skull of Pachycephalosaurus might have protected its brain when it collided with another dinosaur. Scars on the domes of some skulls also support this idea.
Photo via <a href=” ttps://www.goodfreephotos .com/”>Good Free Photos</a>
But some scientists doubt head-butting was possible, saying the shape of its neck makes it unlikely its spine could withstand a head-on collision. And, the top of its head is rounded, so not much surface would collide with the other dinosaur. These scientists think that maybe Pachycephalosaurus used glancing blows to the side while fighting others to see who would control a territory. It also might be that Pachycephalosaurus having a big head just helped males to attract females. One thing scientists do agree on is that its thick skull wouldn’t have been much good as defense if it were attacked by Tyrannosaurus because the rest of its body had no defenses.
However, it wasn’t just the thickness of the skull that made this dinosaur weird. Across the back of the dome and on its snout, it had large circular bumps (see skull above). Bumps aren’t all that weird, but scientists think most of the bumps started out as spikes, flattening as the dinosaur grew older. They have found skulls of smaller dome-headed dinosaurs that were thought to be different species of dinosaurs, such as one called Dracorex hogwartsia, which means “the Dragon King of Hogwarts” (named for Harry Potter’s school). They are now thought to be juvenile pachycephalosaurs. It seems odd that spikes would flatten into bumps as the dinosaur grew up, as spikes seem more useful than bumps, but, as I said, this is a weird dinosaur.
Another strange thing was its teeth. In the back of its mouth, it had wide, leaf-shaped teeth, similar to those found in many plant-eating dinosaurs. According to paleontologist, Philip Currie, “We have always been somewhat mystified by what these animals were eating, but I think the teeth at the back of the jaws clearly show it’s an herbivore.” But in 2018, paleontologists reported finding a more complete jaw, and they couldn’t believe what it showed. In the front of its mouth, it had sharp, triangular teeth, that were more like a carnivore.
Paleontologist, Steve Brusatte, said, “It had the combination of a beak with these very sharp, steak knife-like serrated teeth … They must have been eating some kind of meat. Why else would you have steak knives at the front of your mouth?” This combination is very unusual. Scientists have suggested that this means it might be an omnivore, eating both plants and meat. The meat would have been small animals, such as lizards, frogs, or even small mammals; the plants would have been ferns, leaves, and conifer needles.
All in all, Pachycephalosaurus certainly qualifies as a strange and weird dinosaur. It’s one of my favorites, and I hope it is now one of yours.
On a summer day in 2006, a fossil hunter named Clayton Phipps made a discovery that ranks among the most spectacular dinosaur finds ever. While exploring the rocky terrain of the Montana hills, he spotted a bit of bone weathering out of the rock. It turned out to be part of the pelvis of a Triceratops. After digging on and off for months, he discovered that it might be a complete skeleton of a 28-foot-long Triceratops.
That’s rare, but that’s not all he found. With it, he unearthed the only 100% complete skeleton of a juvenile Tyrannosaurus Rex that has ever been found. It is 22 feet long, with all the bones are articulated – in their natural positions next to each other – which is very rare. And on top of that, they look like they were locked in battle when they died! This is a spectacular discovery! Only one other pair of apparently fighting dinosaurs – a Velociraptor and Protoceratops – has ever been found.
Did the two dinosaurs die fighting each other? Scientists need more time before they can say for sure. Because there was a long court battle over who owned these bones, they are only just now getting to study them. They know that some of the Tyrannosaurus’ teeth are broken, and that some tyrannosaur teeth are in the Triceratops’ bones and body cavity, but they don’t know yet if those teeth belonged to this Tyrannosaurus. If they do, they could have gotten there in a fight, or it could be that the Tyrannosaurus found a dead Triceratops and took a bite. The Tyrannosaurus’ skull is cracked, and one finger is broken. But if the two creatures were killed by a mudslide, the impact of the mud and the debris it carried might have caused those injuries.
However, it is also reasonable to think that those injuries happened in a fight. Scientists have never found skin impressions from a Triceratops frill – until now. There are also skin impressions on the Tyrannosaurus’ feet And they think some of the soft tissue inside the dinosaurs has been preserved, such as the stomachs. It might be possible to find out the last meal of each of these dinosaurs – before they ran into each other!
Scientists are excited about the chance to study these unique dinosaurs. And very soon, the public will get to see them, too. These “Dueling Dinosaurs,” as they have been nicknamed, will be on show for the public at the North Carolina Museum of Natural Sciences in Raleigh, NC, beginning in 2024. I can’t wait to go!
Do you think they died fighting each other? Let me know in the comment section.
Everybody knows where you find mummies – in pyramids in Egypt. But not always. People made the Egyptian mummies, but under just the right conditions, Mother Nature can make them, too. A few, very rare dinosaur mummies have been found. Not just a skeleton but a fossil with skin and soft tissue preserved.
To become a mummy, a dinosaur that died would first need to be protected somehow from predators, so they couldn’t tear it apart. That could happen in a number of ways. The dinosaur could die in a place away from predators or be covered over with water from a flood or a giant mudslide. Some could be covered by the collapse of a sand dune.
Being away from predators isn’t enough. Minerals need to soak into the skin and soft tissue before they have a chance to decay. It helps if the dinosaur is covered with something that slows down the microbes that cause that decay, such as certain kinds of mud. It also helps to have the right kind of skin. Some scientists have suggested that the reason most of the dinosaur mummies that have been found are duckbilled dinosaurs is that there was something in their skin that slowed down decay, giving the skin time to fossilize.
The first dinosaur mummy was found in Wyoming in 1908. It was an Edmontosaurus (ed-MON-to-SAWR-us), a duckbill dinosaur common in the late Cretaceous. Though it’s hard to see in this picture, almost 2/3 of the body is still covered with skin. The skin consists of very small scales, less than two tenths of an inch in diameter. Unlike those of many reptiles, the scales are more like separate bumps than overlapping scales.
The Children’s Museum of Indianapolis, CC BY-SA 3.0, via Wikimedia Commons
Henry Fairfield Osborn, Public domain, via Wikimedia Commons
Different sizes are clustered together. The scales on the upper side of the body are larger than those on the lower side. Soft tissue between the claws on its hands suggests that it had padded feet, and tissue above the spine suggests it had a soft ridge along the back of the neck and spine.
The Children’s Museum of Indianapolis, CC BY-SA 3.0, via Wikimedia Commons
Several other duckbill dinosaur mummies were found during the 1900s, but they didn’t have as much preserved soft tissue or skin. The next dinosaur mummy of any importance was not found until 2000 when scientists in Montana unearthed a Brachylophosaurus (BRACK-uh-LOF-o-SAWR-us), which is another type of duckbilled dinosaur. They named it Leonardo (nearby graffiti from 1916 said that Leonard loved Geneva). This mummy was 90% complete and revealed that the neck had unusually strong muscles and that its skin was scaly, similar to Edmontosaurus. Scientists were able to examine the contents of its stomach. It ate leaves, conifers, ferns, and flowering plants like magnolias. Its stomach also revealed parasites – small bristly worms.
Probably the most spectacular dinosaur mummy of all was discovered in 2011 in Alberta, Canada. It is Borealopelta (BORE-e-AL-o-PEL-ta), not a duckbilled dinosaur but a nodosaur, an armored dinosaur. In life it was 18 feet long and weighed about 3000 pounds. The back legs and tail are missing, but what is there is amazing. The skin was so well preserved that scientists were able to use a mass spectrometer to find out what the color of the dinosaur was.
The back and sides of the dinosaur were a dark reddish brown, while the belly was a lighter reddish brown. We see that pattern of coloring, ark on top and light underneath, in many animals today. It helps those animals hide from predators. Not only was the skin well preserved, but also the armor itself. Usually, the armor falls off armored dinosaurs before they fossilize. Sometimes pieces of armor are found nearby, but often they aren’t. This mummy shows exactly where and how every piece of armor was attached. In addition, scientists have learned that the spikes were covered with keratin, the same stuff that fingernails are made of. This made the armor look bigger: the better to scare away predators – or perhaps to attract a mate.
No doubt additional exciting dinosaur mummies will be found in the future. A potential one, discovered in Montana in 2014, still lies encased in a 35,000-pound block of stone, waiting to be dug out. Each mummy helps fill in gaps in our knowledge of how dinosaurs looked and behaved.
Which do you like better? Egyptian mummies or dinosaur mummies? Let me know in the comment section below.
Greshko, Michael. “The Amazing Dinosaur Found (Accidentally) by Miners in Canada.” National Geographic. June 2017. https://www.nationalgeographic.com/magazine/ article/dinosaur-nodosaur-fossil-discovery
In the first movie of the Jurassic Park series, the second scariest dinosaur was Velociraptor. (Scariest? T-rex, of course.) The movie showed a creature that was about six feet tall, with a huge foot claw that it held upright. Its body was thick, like a tyrannosaur, it was highly intelligent, and it hunted in a pack during the day. Given that most of us like watching movies with scary creatures, a star was born. Overnight Velociraptor became famous.
But like many movies, Jurassic Park got it wrong. In fact, pretty much all of it was wrong. To start with, Velociraptor was little: only about three feet tall (one meter) measured at the hip. From the tip of its nose to the end of its tail, it measured about six feet (2 meters), but almost half of that length was its long, stiff tail. When Velociraptor was fully grown, it weighed only about 33 pounds (15 kg). A Great Dane, which is about the same height, can weigh up to 140 pounds (64 kg.).
Why is the height of a dinosaur measured at its hip?(Click Me)
Dinosaurs that walked on two legs didn’t stand upright. They leaned forward (sometimes a little, sometimes a lot) and used their tail to balance their head. This means that the head wouldn’t always be at the same height. It could go up and down. But the legs of dinosaurs are directly under their bodies, so the measurement of height at the hip would always be the same.
The movie showed Velociraptor covered with scales, but scientists have found marks on the arm and tail bones of this dinosaur that show feathers were attached there. In fact, it’s likely their whole bodies were covered with feathers. However, though their arms may have looked like wings, Velociraptors weren’t capable of flight. Their arms were too short, and their bodies were too long. Instead, they walked on two legs.
If you’re now picturing a fluffy, cute, little dinosaur, think again. It would not make a good pet. It may have been only about the size of a Great Dane, but it was a fierce hunter. Its upright, sickle (curved in an arc) claw was about 2½ inches (6.5 cm.) long, measured around the outer edge. That’s not very big compared to that claw in the movies, but an eagle’s talons are only two inches long, and think of the damage it can do with those!
The movie did get it right that Velociraptor was a carnivore, a meat eater. It had a mouth full of very sharp, serrated (having a jagged edge , like a steak knife) teeth. Its head was flat with large eyes that enabled it to see very clearly. It also had great senses of smell and hearing. The three claws on each hand were very sharp. Each foot had sharp claws, too, including that famous sickle claw. This claw was held up off the ground, which kept it very sharp. Claws that scrape along the ground become dull.
The movie showed a highly intelligent, coordinated attack by a pack of Velociraptors in the daytime. However, none of that is true. First, Velociraptor was not that smart. Its brain was large compared to its body, but it’s a small body and a small brain. It was about as smart as a bird of prey, such as a hawk. Many modern mammals could have outthought it.
Next, it probably wasn’t a pack hunter. Strangely, it is their teeth that make some scientists think this. Scientists have analyzed the teeth of young Velociraptors and compared them to adult Velociraptors. They’ve found that the chemicals in each set of teeth are different. This is important information because in pack animals the chemical makeup of the teeth is usually the same because old and young share the same food.
Young animals which are not taken care of by their parents or the pack usually have different chemicals in their teeth than adults because they eat different food. They would eat lizards and insects, small creatures that a little dinosaur could catch. As an adult they’d eat bigger things. Young animals that have not been taken care of by their parents also tend not to hang out with others of their kind. And, dinosaurs are more closely related to reptiles and birds which generally do not hunt in packs. So, at least for right now, these facts have caused scientists to lean toward the theory that Velociraptor did not hunt in packs.
But whichever way it goes, it is certain that Velociraptor’s slim body and long legs made it a fast runner. It could run as fast as a roadrunner, maybe as fast as 25 mph (40 kph). Small prey, with their short legs, didn’t stand a chance of outrunning it. Their only chance of escaping lay in having a big head start because Velociraptor’s leg muscles weren’t strong enough to run really fast over a long distance.
Sometimes Velociraptor is shown in books and movies using its sickle claw to rip open its prey, but that isn’t likely. The claw could break through the skin of a dinosaur, but tests show it wasn’t strong enough or long enough to kill another animal. Most likely that claw was used to hold onto its prey while Velociraptor used its other claws and its teeth to kill. Hawks and various other birds of prey use their talons in this way.
Velociraptors also probably hunted at night, not in the day as in Jurassic Park. Scientists have noted that all birds and many reptiles alive today have a ring of bone around the eye. In those animals that hunt at night, the opening in the ring is large, to let in as much light as possible. Those that hunt in the day have a much smaller opening. Velociraptor has a large opening in its ring of bone. This makes it almost certain that it hunted at night. And that makes sense as the area Velociraptor lived in was mostly desert. It would want to hunt at night when it would be cooler. Its body wouldn’t overheat, and small creatures would be more likely to come out.
All in all, Velociraptor is not much like the creature in the movie that made it famous, but the real Velociraptor was still a deadly predator.
Which do you like better? The real Velociraptor or the one in the movie? Please let me know in the comments below.
Maxwell, W. Desmond, and John H. Ostrom. “Taphonomy and Paleobiological Implications of Tenontosaurus-Deinonychus Associations.” Journal of Vertebrate Paleontology, vol. 15, no. 4, [Society of Vertebrate Paleontology, Taylor & Francis, Ltd.], 1995, pp. 707–12, http://www.jstor.org/stable/4523664.
An old dinosaur joke goes: “What happens if you let a tyrannosaur into your house?”
“Tyrannosaurus wrecks.”
In fact, that is just what would happen. The name Tyrannosaurus rex means “King of the Tyrant Lizards.” The sheer size and power of a tyrannosaur is amazing. An adult T-rex could grow up to 40 feet long. That’s four feet longer than a school bus. And it weighed about 9 tons. That’s 18,000 pounds. Its height was about 13 feet tall at its hip. (Paleontologists measure there because Tyrannosaur didn’t stand straight up.) Its head was huge – five feet long – and it had banana-shaped teeth that could grow as long as 12 inches! The teeth were also serrated, having jagged edges running up and down the front and back of the tooth. This meant it could slice through meat like a steak knife. Its bite was so powerful it could go right through almost any bone. Joseph Castro, a writer for Live Science, compared the strength of its bite to the same impact as a medium-size elephant sitting down.
The Children’s Museum of Indianapolis, CC BY-SA 3.0, via Wikimedia Commons
T-rex lived at the very end of the reign of dinosaurs, about 68-66.5 million years ago, during what’s called the Cretaceous Period. It was first discovered in Montana in 1902, though fossils of it have been found from Canada to Texas. It was, of course, a meat-eater, a carnivore. Footprints of other, similar dinosaurs have been found showing they traveled in packs, so Tyrannosaurus might have done so, too.
For years paleontologists have argued about whether this huge creature was an active predator, hunting and killing live prey, or a scavenger, feasting on animals that were already dead. They were certainly big enough to chase other dinosaurs away from any dead animal, but many people feel Tyrannosaurus wouldn’t have been able to find enough to eat this way.
myfavoritedinosaur.com and LadyofHats, CC BY 3.0, via Wikimedia Commons
Scientists argued for years, but a study published in 2013, provided evidence supporting the idea of T-rex, the hunter. Fossils from a hadrosaur, a duckbilled dinosaur, were dug up in South Dakota, and the crown of a Tyrannosaurus tooth was found embedded in its tail. But the tail showed signs that it had healed after being bit. An already dead animal doesn’t heal. The T-rex must have attacked it, but the duckbilled dinosaur got away.
Another clue that T-rex was a hunter comes from studies that show that the powerful muscles in its legs could have allowed it to run as fast as 25 mph. A scavenger doesn’t need to run that fast, though most likely Tyrannosaurus ambushed its prey, rather than chasing it for long distances. It was just too heavy to run flat out for long. It was a sprinter, not a miler.
Just recently, an incredible fossil find has been uncovered. It was found in 2006, but lay encased in the surrounding rock for years. It shows a juvenile Tyrannosaurus seemingly locked in battle with a young Triceratops. However, scientists aren’t sure yet that they were fighting each other. Some of the Tyrannosaurus’ teeth are broken, and some tyrannosaur teeth are in the Triceratops’ bones and body cavity, but they don’t know yet if those teeth belonged to this Tyrannosaurus. If they do, they could have gotten there in a fight, or it could be that the T-Rex found a dead Triceratops and took a bite. The Tyrannosaurus’ skull is cracked, and one finger is broken. But if the two creatures were killed by a mudslide, the impact of the mud and the debris it carried might have caused those injuries. However, it is also reasonable to think that those injuries could have happened in a fight. Even though Tyrannosaurus likely was a hunter, it probably wouldn’t have turned down a meal that was already killed.
Another area of debate is why Tyrannosaurus had such small arms. They are so short T-rex couldn’t even reach its mouth with them. Some scientists argue that they are short because the dinosaur didn’t need them. With such a powerful bite, it didn’t need to fight with claws. And with so much space in its body needed for powerful neck muscles, there wasn’t much room for arm muscles. Others argue that the arm muscles were strong enough to hold struggling prey, so they were useful for something.
There are many competitors today for the title “King of the Dinosaurs.” Giganotosaurus was shaped much like Tyrannosaurus and was about eight feet longer. Spinosaurus was thinner but may have been more than 50 feet long. But size isn’t everything. Tyrannosaurus had a larger brain, which gave it exceptional sight and smell. And don’t forget that bite force. No other animal, living or extinct, has ever had a more powerful bite. For many, that means T-rex can keep its crown.
When did you start to love dinosaurs? I began when I watched The Flintstones on TV as a kid. It was a cartoon show about a “stone age” family, Fred and Wilma Flintstone. The people on the show used dinosaurs for all kinds of things, such as a little dinosaur as a garbage disposal in the kitchen and a big dinosaur for construction. Their airplanes were Pteranodons. I wanted a pet dinosaur, like the Flintstones had, but I knew it was all make-believe.
I learned about real dinosaurs by going to the Field Museum in Chicago. We went there on field trips throughout elementary school, and my family visited there, too. Staring up at those huge skeletons was just amazing! They were so big! I didn’t even come up to their knees. There weren’t as many of them in the museum then as there are now. And the scientists still had a lot to discover, such as that dinosaurs didn’t drag their tails. But those extinct creatures stirred my imagination. If there was a real Jurassic Park, I would go in a second.
I remember in sixth grade reading The Lost World by Sir Arthur Conan Doyle. It was a story about a group of explorers who find live dinosaurs on a plateau in South America. It inspired me to write the first story I ever wrote. It was about a group of kids who find live dinosaurs on a plateau in South America. Well, okay, it wasn’t very original, but it was still fun.
Dinosaurs were popular back then, but they weren’t in the media as much as they are now. I still loved them, but they took a backseat as I grew up, got married, and had a child. Then in the late 1980s, I got an opportunity to write a series of dinosaur books for the publisher I worked for. As I did the research, I was amazed at how far paleontology had come. Scientists thought that dinosaurs were far more exciting than they used to think. Dinosaurs weren’t just big plodding monsters, who sat around in swamps munching plants all day. They were as diverse as the different animals alive today. When I was growing up, scientists knew about only a few hundred dinosaurs. Now they have identified more than 2000 different species. Some lived in herds. Others traveled in packs and worked together to bring down large prey. Still others were loving parents who took care of their babies.
I ended up publishing a series of 24 dinosaur books. Most of them are pictured below, with some of the bones from my collection. They sold all across the country, were translated into Spanish, and won Best Children’s Nonfiction Books that year (1989) from the Society of Midland Authors.
Since that time, I’ve published another 12 dinosaur books. I’ve collected more than 50 dinosaur bones and replicas, and I’ve traveled throughout the Midwest with those bones doing programs on dinosaurs (please see my web site http://www.janetriehecky.com).
I’ve kept up with the current research and plan most of my vacations Around visiting dinosaur museums around the country. I love how weird and big and awesome dinosaurs are, so I thought I’d start a blog on dinosaurs. Along the way I’ve found out some pretty amazing things about them – like, did you know that half the length of a Mamenchisaurus was its neck? – and I’d like to share what I’ve learned with you.
If you’re interested in finding out more about dinosaurs, you can visit here once a week. Also, I would love to learn how you started to love dinosaurs. Please drop a note with your dinosaur story in the comment field.
Dinosaur Lady 
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