Paleontologists can now add fish to the list of prey the small bird-like dinosaur Microraptor ate during its heyday 120 million years ago.
A study published in the journal Evolution led by Chinese paleontologist Lida Xing examined the innards of an especially well-preserved Microraptor gui specimen found in volcanic ash, and discovered fossilized fish within the dinosaur’s stomach.
The study revealed that Microraptor was a smart predator—it could adapt to eat based on what was available in its habitat. Previously studied specimens of Microraptor from early Cretaceous China, the forests of which M. gui made its home, indicate it lived a life exclusively in the trees, feeding on small mammals and birds. But the remains of teleost fish —ray-finned fish —found in this fossil were indication that Microraptor could depart from its home in the trees in order to find food.
The specimen–the largest Microraptor specimen yet discovered– not only added to the dinosaur’s known diet—it also gave the researchers clues as to how it ate. Closer study of Microraptor’s teeth revealed they were angled forward and serrated on only one side—most predators have double-serrated teeth. The reduced serrations lessened the amount of tearing that would occur when a fish was impaled and struggling in the dinosaur’s mouth. When Microraptor scooped up a fish, it would stab it with its teeth then swallow it whole.
Microraptor is considered to be a stepping stone in the evolution of birds from dinosaurs. It had “true flight” feathers in its four wings, but hadn’t evolved to be able to use these feathers for active flying—it would glide through the air from tree branch to tree branch.
Find the study in the journal Evolution.