A well-preserved fossil from China revealed that dinosaurs used elaborate camouflage to hide in the forest. Researchers from the University of Bristol have created a 3D model of the Psittacosaurus to determine their habitat and how they used its different colors to hide in plain sight.

The Psittacosaurus is a long-lost species that lived in the early Cretaceous in China around 120 million years ago. Its name means “parrot-lizard” because its beak is similar to that of parrots. The dinosaur’s countershading camouflage is light on its underside and darker on top. This type of protective coloration is also found in modern animals such as antelopes and fish. It confuses predators because they rely on an object’s shading to assess its shape. The Psittacosaurus might have taken advantage of its skin’s dark and light colors to minimize shadows and flatter its preys.

The Psittacosaurus fossil seems to be pooping. However, scientists explained the dinosaur probably did not die while defecating. Image credit: Jakob Vinther/University of Bristol.

The Psittacosaurus’s pigment probably served other purposes as well, as suggested by National Geographic. The dinosaur had dark stripes on the side of its legs that could have been used to ward off insects, which is similar to what zebras’ adorning slashes accomplish.

The dinosaur’s camouflage could have also hardened its skin. Spots on the outside of the front legs had pigment molecules with toughening qualities. Detailed results of the study were published Thursday in the journal Current Biology.

The fossil was exquisitely preserved and let scientists analyze one of the most elaborate dinosaur paint jobs ever seen. Its 3D reconstruction is the most life-like one of a prehistoric animal ever created.

The ancient reptile had horns on either side of its head and long bristles on its tail. It was found in the same rock strata where many feathered dinosaurs have been discovered. The fossil is currently on public display at the Senckenberg Museum of Natural History in Germany.

The truth behind the protruding object that is located in the dinosaur’s bottom could have been pushed by gasses from the animal’s decay. Vinther also suggested that the specimen’s guts could have continued churning after death.

It was previously thought that the camouflage was dead bacteria in fossilized feathers or artifacts, but then researchers discovered they were “melanosomes.” The latter are small structures that carry melanin pigments found in the feathers and skin of many animals.

Professor Innes Cuthill, a behavioral ecologist from the School of Biological Science, explored the distribution of countershading in modern animals. Researchers found difficult to apply the same principles on the extinct animal because it had been crushed flat and fossilized.

It is possible to make out the patterns of preserved melanin without the aid of a microscope when fossils such as the Psittacosaurus’ are well preserved.

Finding Psittacosaurus’ right habitat

Bristol paleontologists Professor Emily Rayfield and Dr. Stephan Lautenschlager studied the fossil for days and took measurements of the bones. They also examined the preserved scales and the pigment patterns with input on muscle structure. Their work made possible the modeling of the dinosaur, which took months.

Local paleoartist Bob Nicholls, who had teamed up with Bristol researchers, stated that the dinosaur was reconstructed from the inside-out. He said there are thousand of scales, different shapes, and sizes and many of them are partially pigmented. He confessed the process was tedious, but they now have the best suggestion as to how the Psittacosaurus looked like in the past.

Psittacosaurus photographed in the Bristol Botanic Garden. Image credit: Jakob Vinther.

After the model was done, Dr. Vinther, Bob Nicholls, and Professor Cuthill took another cast of the piece and painted it all gray to place it in different environments to analyze where the Psittacosaurus used its camouflage.

Vinther said that the fossil’s color patterns provided not only a better picture of how the dinosaur looked like but also new clues about extinct ecologies and habitats.

Researchers placed the gray 3D model in the Cretaceous plant section of the Bristol Botanic Garden and photographed it under the open sky and underneath trees to see how the shadow reacted on the dinosaurs’ skin.

“By reconstructing a life-size 3D model, we were able to not only see how the patterns of shading changed over the body, but also that it matched the sort of camouflage which would work best in a forested environment,” said Professor Cuthill.

The images showed the Psittacosaurus’s coloring provided the best camouflage under diffuse light, meaning the reptile probably lived in the forest rather than in the savanna.

The study authors stated that they found evidence of a forest environment based on plants and wood fossils located in the same rock strata they found the Psittacosaurus fossil.

According to the University of Bristol, researchers will continue to study other types of camouflage in fossils to understand how predators perceived the environment and their role in shaping evolution and biodiversity.

Source: University of Bristol