A 120-million-year-old fossil chook present in China might supply some new clues about how landbound dinosaurs advanced into right now’s flying birds. The dove-sized Cratonavis zhui sported a dinosaur-like head atop a physique just like these of right now’s birds, researchers report within the January Nature Ecology & Evolution.
The flattened specimen got here from the Jiufotang Formation, an historic physique of rock in northeastern China that could be a hotbed for preserved feathered dinosaurs and archaic birds. CT scans revealed that Cratonavis had a cranium that was practically similar (albeit smaller) as these of theropod dinosaurs like Tyrannosaurus rex, paleontologist Li Zhiheng of the Chinese Academy of Sciences in Beijing and colleagues report. This implies that Cratonavis nonetheless hadn’t advanced the cellular higher jaw present in trendy birds (SN: 5/2/18).
Researchers used CT scans to digitally reconstruct the flattened Cratonavis specimen (proven). The scans revealed that the creature had a theropod’s head and a chook’s physique.Wang Min
It’s amongst only a handful of specimens that belong to a not too long ago recognized group of intermediate birds often called the jinguofortisids, says Luis Chiappe, a paleontologist on the Natural History Museum of Los Angeles County who was not concerned within the examine. Its dino-bird mishmash “is not unexpected.” Most birds found from the Age of Dinosaurs exhibited extra primitive, toothed heads than right now’s birds, he says. But the brand new discover “builds on our understanding of this primitive group of birds that are at the base of the tree of birds.”
Cratonavis additionally had an unusually elongated scapula and hallux, or backward-facing toe. Rarely seen in Cretaceous birds, enlarged shoulder blades may need compensated for the chook’s in any other case underwhelming flight mechanics, the researchers say. And that hefty large toe? It bucks the development of shrinking metatarsals seen as birds continued to evolve. Cratonavis may need used this spectacular digit to hunt like right now’s birds of prey, Li’s workforce says.
Filling these sneakers could have been too large of a job for Cratonavis, although. Given its dimension, Chiappe says, the dino-headed chook would have probably been a petite hunter, taking down the likes of beetles, grasshoppers and the occasional lizard slightly than terrorizing the skies.
