This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: It walked on two legs and may have looked like a feathered bear with giant claws. Meet Kayrasaurus changliensis—well, its almost complete skeleton, to be precise.
Paleontologists have described a new species and genus of therizinosaur found in the Yixian Formation of western Liaoning, China, that lived during the Early Cretaceous. Therizinosaurs were a group of primarily plant-eating theropod dinosaurs with long necks, pot bellies and large claws that may have been used for feeding. This new dinosaur measured more than 3.6 meters (11.8 feet) long and is estimated to have weighed between 117 kilograms (258 pounds) and 274 kilograms (604 pounds).
It is thought to be the largest therizinosaurian specimen discovered in the Jehol Biota (an Early Cretaceous ecosystem in northeastern China), at least 1.6 times larger than Beipiaosaurus inexpectus, the previous record holder. But several features distinguish it from other early therizinosaurs, as researchers Chun-Chi Liao, William J. Zanno and Xing Xu detail in a study published in the Journal of Systematic Paleontology.
"As the largest therizinosaurian yet known from the Jehol Biota, K. changliensis bridges morphological gaps between previously described taxa." These distinctive traits include a jaw packed with numerous teeth. The upper jaw carried more than 32 teeth, while the lower jaw had more than 45. They were unusually small and tightly packed.
Its neck vertebrae were also much longer than those of its back, and one of its claws had a raised lip not seen in other therizinosaurs. But the differences don't end there. Its upper jaw had an unusually large opening near the snout, while its nasal bones stretched back to the middle of the eye sockets and split into a strange two-pronged tip.
The lower jaw also featured a tall, triangular side opening. In addition to describing the new dinosaur, the research team suggested how it might have lived alongside its neighbors. They believe the Jehol therizinosaurs may have occupied at least two different ecological niches.
Extract — continue reading at the source.
