Fossils of new dinosaur species found with crocodile bone in its mouth
Paleontologists in Argentina have discovered a new predatory dinosaur -- the fossils of which contained a crocodile bone within the dinosaur's mouth.
The new species, dubbed Joaquinraptor casali, is part of megaraptoran family of theropods -- a group known for their elongated skulls, powerful forearms and large claws, according to a paper published Tuesday in Nature Communications.
Megaraptorans were found across Asia, Australia and South America, but the understanding of the group has been restricted in the past due to a lack of complete fossils, according to the paper.
The well-preserved and partially articulated fossils of J. casali were found in the Lago Colhué Huapi Formation in Patagonia, Argentina. The set of fossils included much of the skull, fore and hind limbs, ribs and vertebrae, and included a fossilized bone of a crocodile leg pressed against its lower jaws.
The individual likely lived between 66 million and 70 million years ago during the Cretaceous period, making it one of the most recently surviving species of megaraptorans, according to the paper.
The researchers suggest the specimen is an adult that had not yet fully matured -- about 19 years old, based on its bone microstructure.
The scientists extrapolated its remains to estimate that the dinosaur was about 23 feet in length and weighed more than 2,200 pounds, according to the paper.
J. casali likely lived in a humid floodplain climate, based on sedimentary evidence, the researchers said.
The presence of the crocodile bone within the fossils offer clues to the feeding behaviors of J. casali, suggesting that it may have been the apex predator of the region, the scientists hypothesized.
J. casali and other megaraptorans were likely the dominant predators in the region, according to the paper. The group went extinct at the end of the Cretaceous period, as did other non-avian dinosaurs.
More research is needed for further insights into J. casali's ecological role and behavior, the scientists said.
