A surprisingly cat-sized “meal” of a dinosaur was found inside a 120-million-year-old Microraptor fossil.
Although the fossil was first described in 2000, it hid an intriguing and historical secret: A reanalysis of the fossil found mammalian foot bones in the raptor’s thorax, the first evidence that a dinosaur ate a mammal.
The finding, described Tuesday in the Journal of Vertebrate Paleontology, builds on previous research on the Microraptor zhaoianus fossil found in the Jiufotang Formation in western China. The middle part of the body of this fossil is missing, but the thorax is visible, and the bones of a tiny right foot, less than two centimeters in size, are perfectly preserved.
Microraptors were three-toed, carnivorous dinosaurs that invaded the trees of the old Earth and were among the smallest dinosaurs ever discovered. Evidence of long hairs thought to have been used for gliding was seen on the limbs of fossils of different microraptor species.
As you can imagine, the food usually eaten does not produce very well-preserved fossil remains. The digestive process that comes after all the biting and chewing usually doesn’t leave much of a meal behind. But scientists have a pretty good idea of the microraptor diet, thanks to fossils with undigested remains in the stomach. This newly found mammal specimen, along with previously found specimens of fish, birds, lizards, and snakes, offers further insight into the diet of microraptors.
“Examples of food inside dinosaurs are very rare to find, so every sample is really important because it provides direct evidence of what they ate,” said David Hone, a paleontologist at Queen Mary University of London and lead author of the new study.
While scientists can say that a foot was found in the stomach of the micropredator, they’re not sure which species it belongs to. The slender fingers look like the small, extinct, opossum-like mammals known as Sinodelphys or the more mouse-like Eomaia. However, the fingers are not long enough to be any of these types.
31474
