PARIS: What did Tyrannosaurus rex really look like? Depending on which artist’s impression you look at, the carnivorous king of the Cretaceous was a dull gray, an earthy brown, maybe a dark green ... perhaps it was ochre, or even the color of a bright lime.
New insights into prehistoric fossils, published Wednesday, may one day help determine what the great dinosaurs looked like in real life.
Scientists said they had uncovered the first-ever traces of pigment in reptile fossils – a dark hue found in three extinct deep-sea beasts distantly related to today’s leatherback turtle.
“This is the first time that ... remains of original pigments have been detected in any [extinct] reptile, including dinosaurs,” Johan Lindgren of Sweden’s Lund University told AFP.
The next challenge will be to identify more pigments, helping paleontologists to reconstruct the coloring of extinct animals.
“This finding potentially allows us to reconstruct the colors of T. rex in the future,” said Lindgren, though for now experts are limited to distinguishing dark areas from light ones.
Lindgren and his colleagues studied molecular remains found on the skin of three marine monsters.
The samples came from a forerunner 55 million years ago of the leatherback turtle; a giant, finned lizard known as a mosasaur dated to 86 million years ago; and a dolphin-like reptile called an ichthyosaur, around 190 million years old.
The remains took the form of micrometer (millionth of a meter) sized structures that, according to previous studies, were either pigment traces or the vestiges of bacteria.
The new investigation claims to settled that debate with in-depth microscopic analysis – revealing the remains to be traces of the most common skin pigment, melanin.
Coloration in the animal kingdom serves multiple purposes: from camouflage or sexual display to UV protection and heat retention.
Little is known about the coloring of long-extinct animals, given that pigmentation is carried in the quick-to-decay skin. But sometimes, as in this case, scientists are lucky to find soft tissue preserved as an “organic film.”
The team pointed out there was a close correlation between the amount of melanin in skin, and the darkness of color.
The fossil tissue of all three extinct sea beasts contained very tightly packed pigment granules.
This led the scientists to conclude the creatures had “an overall dark coloration” similar to the leatherback turtle, whose top is almost entirely black, Lindgren said.