#sinornis

Source: https://en.wikipedia.org/wiki/Sinornis

Name: Sinornis santensis

Name Meaning: China Bird 

First Described: 1992

Described By: Sereno & Rao

Classification: Dinosauria, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Averaptora, Avialae, Euavialae, Avebrevicauda, Pygostylia, Ornithothoraces, Enantiornithes, Cathayornithiformes

Yeah, 1992 was a crap year for non-avialaen dinosaur discoveries... and avialaen dinosaur discoveries. I gotta scrape at the barrel for this. Still, Sinornis is a pretty cool dinosaur, all things considered. It lived about 135 million years ago, in the Valanginian age of the Early Cretaceous. It was found in the Jiufotang Formation at Liaoning, People’s Republic of China. It was about the size of a sparrow, and it was a transitional form between the very primitive early bird Archaeopteryx and modern forms. It lent much insight into the evolution of flight in modern birds, since Archaeopteryx did not have many of the features of modern birds with regards to flight and perching. It, like many early birds, had a mouth fully of teeth; most of its advanced characteristics were related to flight and perching. Based on its breastbone and shoulder structures, it was capable of flight similar to modern birds (and had the muscles necessary for it;) it had modified wrist bones that would allow the wrist to bend sharply back to tuck the wings during flight or rest. It had reduced claws, and small hands with a steady middle finger to allow for flight feather anchorage. It had separate finger bones, well adapted for flight, which in combination with its small form made it easier to fly. It was also capable of perching and climbing. It lived in a primarily arboreal habitat, and probably inhabited an ecological niche similar to sparrows. 

Source: 

https://en.wikipedia.org/wiki/Sinornis

The Chinese bird, Sinornis (1992)

Phylum : Chordata Class : Aves Order : Enantiornithes Infraorder : Euenantiornithes Genus : Sinornis Species : S. santensis

Early Cretaceous (120 Ma)

15 cm long (size)

Jiufotang formation, China (map)

Paul Sereno et al. considered a similar prehistoric bird species from the same formation, Cathayornis, to be a junior synonym of Sinornis. They interpreted the anatomies of the two as very similar and sharing key autapomorphies of the pygostyle.

However, in 2001, Zhou and Hou continued to distinguish Cathayornis from Sinornis by the former's larger size, a shorter, straighter, finger number I, with a slightly longer claw (ungual), the absence of an atitrochanter, and other features. A paper describing a second species of Cathayornis in 2008 by Li et al. also considered the genera to be distinct.