The first evidence that theropods (meat-eating dinosaurs) ate contemporaneous birds and other carnivorous dinosaurs has been discovered in northeastern China. A joint Chinese-Canadian team of paleontologists, led by Phil Bell from the Pipestone Creek Dinosaur Initiative in Canada, described the last meals of Sinocalliopteryx gigas in an article recently published in the journal PLoS One. Sinocalliopteryx was a 6-foot-long compsognathid theropod whose body was covered by fuzzy feathers – the same group as the "compies" in the book Jurassic Park (depicted much smaller than Sinocalliopteryx, and only seen in the second and third JP movies). It lived 120 million years ago, at a time when volcanic eruptions covered the land with lava, and consequently (and conveniently for us) often fossilized specific moments in time. Inside the stomach of one of these Cretaceous-era dinosaurs was the leg of the relatively large feathered dromaeosaurid dinosaur, Sinornithosaurus. In a second individual of S. gigas were bits of a smaller Mesozoic bird Confuciusornis, along with bones of a dinosaur that showed evidence of stomach acid decomposition. This discovery has demonstrated a trait that Sinocalliopteryx shared with modern-day crocodiles – the ability to vary stomach acidity depending on the contents of a given meal.
Scientists are still trying to determine the means of predation – did Sinocalliopteryx scavenge or actively hunt its prey? The study's authors are leaning toward active predation because two species of the same type were found in the predator’s stomach, suggesting that Sinocalliopteryx was choosy about its food. Furthermore, catching flying prey is not an easy task; meaning that Sinocalliopteryx must have perfected its predatory method over time.
Find more about the discovery at Live Science.
Read the original publication in the journal PLoS One.