Researchers from the Institute of Paleontology and Paleoanthropology of Vertebrates (IVPP) of the Chinese Academy of Sciences discovered a partial fossil skeleton of a tiny extinct bird of 120 million years. An interesting feature of the find is that the animal skull has similar features with the Tyrannosaurus of the Rex – one of the largest predators of the semiranosavride family. The opening is reported in the article published in the journal Nature Communications.
Bird’s corpse fell into a small lake on the territory of the modern province of Liaoning in the north-east of China, where it turned into fossil remains. The skull of a length of two centimeters resembles a smaller version of the type of tyrantosaurus on structural and functional features. This is an additional proof that the earliest birds on Earth retained many features of their immediate ancestors – dinosaurs. In general, the skull of the birds of the Mesozoic era functioned more like dinosaurs than in living birds.
Detailed reconstruction of the genealogical tree of birds showed that the new fossil species belongs to the extinct group of birds called enantiornitins (enantiornithins) and the most widely common group of ancient birds in the chalky period. For modern birds, the so-called kinetic skull is characterized when the upper jaw is capable of moving vertically relative to the cranial box. Such mobility is achieved due to the special structure of the square bone forming the jaw joint. However, enantiorites, as well as the tyrannosavrov and ornithosaurs (Troodontide and Dromeosaurov), the kinotics at the skull is missing.
The temporal areas of the new species skull are also very different from modern birds. He has two bone arcs to attach the muscles of the jaw, like reptiles, which makes the back of the skull tight and stable to bone offset. In general, the Nakhodka confirms well-reasonable statement that the first birds were the closest relatives of the predatory dinosaurs.