The authors of the study also showed that during the evolution of dinosaurs to birds, the first metatarsal bone became shorter due to the process of natural selection. When the bone reached the optimal size, which is less than a quarter of the length of the second metatarsal bone, its previous functions were also lost.
The unique feature of the large metatarsal bone in Cratonavis can be compared to the Balaur dinosaur from the late Cretaceous, a member of a group of feathered carnivores called Dromisaurus. Elongated humerus was previously seen in Cretaceous birds such as Yixianornis and Apsaravis.
According to paleontologist Min Wang and one of the main authors of the study, the broad scapula allowed the species to rotate its wings better, thus compensating for the lack of other flight capabilities.
According to the authors, the abnormal shape of the head bone and sole of the foot in Kratonavis indicates skeletal flexibility in these early birds. The unique composition of the anatomy of Cratonavis jui could be a sign of how species change and evolve.
This research in the journal Nature Ecology & Evolution It’s been published.