Gut contents of the dinosaur Sinocalliopteryx gigas suggest the predator chowed on cat-size feathered dinosaurs called Sinornithosaurus (illustrated in left panel), as well as crow-size birds known as Confuciusornis (right). (Photo : Cheung Chungtat. (2012) PLoS ONE )
When you think of a dinosaur, you probably think of a huge, hulking beast that terrorized Jeff Goldblum and his children through an amusement park. But dinosaurs can be small and nimble creatures too. Take Sinocalliopetryx for instance. This small raptor-like dinosaur was flightless even though it had feathers, but was still adept enough to capture flying dinosaurs.
Researchers from the University of Alberta found that the remains of three flying dinosaurs in the belly of a Sinocalliopetryx. This is the first instance of a predator being linked to the killings of multiple flying dinosaurs.
The flying dinosaurs found in the Sinocalliopetryx's stomach were Confuciusornis, an early ancestor of modern-day birds.Sinocalliopetryx did not have any apparent hunting tools to give it an advantage against creatures that could fly, so researchers guess that it must have used stealth to capture its prey.
"Sinocalliopetryx didn't have wings or the physical tools needed to be an adept tree climber," said Scott Persons, a University of Alberta paleontology student and co-author of the paper.
"The fact that this Sinocalliopteryx had, not one, but three undigested birds in its stomach indicate it was a voracious eater and a very active hunter," he added.
Sinocalliopteryx was a dinosaur rougly two meters in length, about the size of a modern-day wolf. The disovery shows that this dinosaur was able to consume prey more than a third its own size. Researcers theorize that it was such an active hunter because its feathers kept its temperature and metabolism higher than other dinosaurs, requiring it to hunt more often and more aggressively.
The researchers also examined a second Sinocalliopteryx from China and found that it had a Sinornithosaurus in its stomach.
"Sinornithosaurus is a relative of Velociraptor which means this is the first direct evidence of a raptor becoming another predatory dinosaur's meal," said Persons.