What Color Were Dinosaurs?

             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.

Used with permission © Royal Tyrrell Museum of Palaeontology, illustration by Julius Csotonyi

            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.

Matt Martyniuk, CC BY 3.0, via Wikimedia Commons

            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.

Lucas-Attwell, CC BY-SA 4.0, via Wikimedia Commons

            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. 

Conty, CC BY 3.0, via Wikimedia Commons

            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.

Entelognathus, CC BY-SA 4.0, via Wikimedia Commons

            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.

Vinther et al., CC BY 4.0, via Wikimedia Commons

            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.

Sources (Click Me)

Black, Riley. “The Colors of Dinosaurs Open a Window to Study the Past.” Smithsonian Magazine. 21 May 2019. https://www.smithsonianmag.com/science-nature/colors-dinosaurs-open-new-window-study-past-180972070/

—. “Microraptor was a Glossy Dinosaur.” Smithsonian Magazine. 9 March 2012. https://www.smithsonianmag.com/science-nature/microraptor-was-a-glossy-dinosaur-119691559/

Caihung.” Wikipedia. 18 May 2021. https://en.wikipedia.org/wiki/Caihong

“Dinosaurs – Sinosauropteryx prima.” Australian Museum. 12 Feb. 2020. https://australian.museum/learn/dinosaurs/fact-sheets/sinosauropteryx-prima/

Dunham, Will. “Scientists decipher color of ‘super cute’ bristly dinosaur.” Reuters. 2021. https://www.reuters.com/article/us-science-dinosaur/scientists-decipher-color-of-super-cute-bristly-dinosaur-idUSKCN11L1OI

“Spectacularly Detailed Armored Dinosaur ‘Mummy’ Makes Its Debut.” Smart News. Smithsonian Magazine. 2021. https://www.smithsonianmag.com/smart-news/mummified-armored-dinosaur-makes-its-debut-1-180963311/

Woodford, Chris. “Mass Spectrometers.” Explain That Stuff! 4 Feb., 2021. https://www.explainthatstuff.com/how-mass-spectrometers-work.html

Yong, Ed. “The Renaissance of Technicolour Dinosaurs Continues (And the Gloves Come Off). Not Exactly Rocket Science. National Geographic.com. 4 Feb. 2010. https://www.nationalgeographic.com/science/article/the-renaissance-of-technicolour-dinosaurs-continues-and-the-gloves-come-off

Note: Title Image Sourced from BBC Science Focus Magazine

Dinosaur Mummies

            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.

AntoninJury, CC BY-SA 4.0, via Wikimedia Commons

            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.

ケラトプスユウタ, CC BY-SA 4.0, via Wikimedia Commons

            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.

© Royal Tyrrell Museum of Palaeontology, illustration by Julius Csotonyi

            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.

Sources (Click Me)

Brachylophosaurus. Wikipedia. 22 March 2021, https://en.wikipedia.org/wiki/ Brachylophosaurus#cite_note-MTT06-7

“Dinosaur Mummies.” Fossil Wiki. Fandom. n.d. https://fossil.fandom.com/wiki/ Dinosaur_mummies#Discovery_and_analysis

“Fossil ‘Mummy’ Shows Glimpse of Dinosaur Skin.” American Museum of Natural History.

            28 April, 2017, https://www.amnh.org/explore/news-blogs/news-posts/fossil-mummy-shows-glimpse-of-dinosaur-skin.

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

“Nodosaur Dinosaur ‘Mummy’ Unveiled with Skin and Guts Intact.” All That’s Interesting. 19 June 2020, https://allthatsinteresting.com/nodosaur-dinosaur-mummy.

“Spectacularly Detailed Armored Dinosaur “Mummy” Makes Its Debut.” Smart News. Smithsonian Magazine. 2021. https://www.smithsonianmag.com/smart-news/mummified-armored-dinosaur-makes-its-debut-1-180963311/