Nav: Home

Researchers ID pigment from fossils, revealing color of extinct animals

September 28, 2015

Scientists from Virginia Tech and the University of Bristol have revealed how pigment can be detected in mammal fossils, a discovery that may end the guesswork in determining the colors of extinct species.

The researchers discovered the reddish brown color of two extinct species of bat from fossils dating back about 50 million years, marking the first time the colors of extinct mammals have been described through fossil analysis.

The techniques can be used to determine color from well-preserved animal fossils that are up to 300 million years old, researchers said.

"We have now studied the tissues from fish, frogs, and tadpoles, hair from mammals, feathers from birds, and ink from octopus and squids," said Caitlin Colleary, a doctoral student of geosciences in the College of Science at Virginia Tech and lead author of the study. "They all preserve melanin, so it's safe to say that melanin is really all over the place in the fossil record. Now we can confidently fill in some of the original color patterns of these ancient animals."

The research involved scientists from the U.S., the United Kingdom, Germany, Ethiopia, and Denmark. It is being published this week (Sept. 28) in the Proceedings of the National Academy of Sciences.

The researchers said microscopic structures traditionally believed to be fossilized bacteria are in fact melanosomes -- organelles within cells that contain melanin, the pigment that gives colors to hair, feathers, skin, and eyes.

Fossil melanosomes were first described in a fossil feather in 2008 by Jakob Vinther, a molecular paleobiologist at the University of Bristol and the senior author of the current study.

Since then, the shapes of melanosomes have been used to look at how marine reptiles are related and identify colors in dinosaurs and, now, mammals.

"Very importantly, we see that the different melanins are found in organelles of different shapes: reddish melanosomes are shaped like little meatballs, while black melanosomes are shaped like little sausages and we can see that this trend is also present in the fossils," Vinther said. "This means that this correlation of melanin color to shape is an ancient invention, which we can use to easily tell color from fossils by simply looking at the melanosomes shape."

In addition to shape, melanosomes are chemically distinct.

Using an instrument called a time-of-flight secondary ion mass spectrometer, scientists identified the molecular makeup of the fossil melanosomes to compare with modern melanosomes.

In addition, researchers replicated the conditions under which the fossils formed to identify the chemical alteration of melanin, subjecting modern feathers to high temperatures and pressures to better understand how chemical signatures changed during millions of years of burial.

"By incorporating these experiments, we were able to see how melanin chemically changes over millions of years, establishing a really exciting new way of unlocking information previously inaccessible in fossils, Colleary said.

The work was carried out at the University of Bristol, where Colleary was a master's student working with Vinther, and the University of Texas at Austin. It was supported by funds from UT Austin, National Geographic, and the University of Bristol.

"It was important to bring microchemistry into the debate, because discussion has been going on for years over whether these structures were just fossilized bacteria or specific bodies where melanin is concentrated," said Roger Summons, the Schlumberger Professor of Earth Science at the Massachusetts Institute of Technology, who was not involved in the research. "These two things have very different chemical compositions."

Summons, who was part of a research team that studied fossils of squid to show that ink from the Jurassic period was chemically indistinguishable from modern cuttlefish ink, said the study further helps demonstrate how all living things on Earth have evolved in concert.

"How color is imparted and how we characterize it in fossils are important, because they inform us about a very specific aspect of the history of life on our planet," Summons said. "For complex animal life, color is a factor in how individuals recognize and respond to others, determine friend or foe, and find mates. This research provides another thread to understand how ancient life evolved. Color recognition was an important part of that process, and it goes far back in the history of animals."
-end-


Virginia Tech

Related Fossils Articles:

Tiny fossils reveal backstory of the most mysterious amphibian alive
Researchers have determined that the fossils of an extinct species from the Triassic Period are the long-missing link that connects Kermit the Frog's amphibian brethren to wormlike creatures with a backbone and two rows of sharp teeth.
Moroccan fossils show human ancestors' diet of game
New fossil finds from the Jebel Irhoud archaeological site in Morocco do more than push back the origins of our species by 100,000 years.
South African cave yields yet more fossils of a newfound relative
Probing deeper into the South African cave system known as Rising Star, which last year yielded the largest cache of hominin fossils known to science, an international team of researchers has discovered another chamber with more remains of a newfound human relative, Homo naledi.
Research sheds new light on 'world's oldest animal fossils'
A team of researchers, led by the University of Bristol, has uncovered that ancient fossils, thought to be some of the world's earliest examples of animal remains, could in fact belong to other groups such as algae.
Viral fossils reveal how our ancestors may have eliminated an ancient infection
Scientists have uncovered how our ancestors may have wiped out an ancient retrovirus around 11 million years ago.
World's oldest plant-like fossils discovered
Scientists at the Swedish Museum of Natural History have found fossils of 1.6 billion-year-old probable red algae.
World's oldest fossils unearthed
Remains of microorganisms at least 3,770 million years old have been discovered by an international team led by UCL scientists, providing direct evidence of one of the oldest life forms on Earth.
New study gives weight to Darwin's theory of 'living fossils'
A team of researchers from the University of Bristol studying the 'living fossil' Sphenodon -- or tuatara -- have identified a new way to measure the evolutionary rate of these enigmatic creatures, giving credence to Darwin's theory of 'living fossils.'
Fossils found reveal unseen 'footprint' maker
Fossils found in Morocco from the long-extinct group of sea creatures called trilobites, including rarely seen soft-body parts, may be previously unseen animals that left distinctive fossil 'footprints' around the ancient supercontinent Gondwana.
The best way to include fossils in the 'tree of life'
A team of scientists from the University of Bristol has suggested that we need to use a fresh approach to analyze relationships in the fossil record to show how all living and extinct species are related in the 'tree of life.'

Related Fossils Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".