Fossils reveal flightless raptor preyed on flying dinosaurs
What you eat tells a lot about one's lifestyle. This is especially true in the animal kingdom and interestingly important for extinct species we know little about.
Recent finds of two large compsognathid Sinocalliopteryx gigas in China's Liaoning province by a paleontology team from the University of Alberta have drawn conclusions that this species was a stealthy hunter based on what they found in the dinosaurs' bellies.
The fossils of two Sinocalliopteryx paint a picture of how this wolf-sized, raptor-like dinosaur hunted and tells a lot about the species' prowess.
One specimen revealed three Confuciousornis, a small flying dinosaur resembling a modern bird's skeleton in its stomach. This implies the Sinocalliopteryx was capable of not only tackling carnivorous prey more than a third its own size, but that because of the similar state of digestion, the food was consumed in rapid succession confirming they were actively hunted as opposed to scavenged.
"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," said Persons.
The other specimen revealed one of the Sinocalliopteryx's last meals as a Sinornithosaurus, a small, feathered, meat-eater related to the Velociraptor. This species is about the size of a house cat and may have been able to fly or glide short distances.
Scott Persons, a paleontology student at the University of Alberta and research coauthor, says Sinocalliopteryx may have used stealth to stock the flyers as the "Sinocalliopteryx didn't have wings or the physical tools needed to be an adept tree climber," said Persons.
Much like the way a wild cat will prowl and pounce on a species capable of flying, researchers assume the Sinocalliopteryx was a predator that could reach its striking distance before the prey took flight. Even though the prey may have been slow to take off and could only fly short distances, the evidence of bird predation in Sinocalliopteryx suggests that it was a highly capable stealth hunter.
According to the researchers, this is the first time a predator has been linked to the killing of multiple flying dinosaurs and the first time a raptor has been discovered in the stomach of another dinosaur.
These finds allow scientists to understand more about prehistoric times and evolutionary patterns leading to more confident conclusions about how these dinosaurs lived on Earth.
Read more at PLoS ONE.
Illustration by Cheung Chungtat.