Sinovenator changii
From EvoWiki
Sinovenator changii Xu et al, 2002 "Meeman Chang's Chinese hunter"
| See Sinovenator in Wikipedia, the free encyclopedia. |
Discovered in the Yixian Formation of western Liaoning China, Sinovenator changii is an exceptionally bird-like basal troodontid. S. changii is refered to Troodontidae based on the following characters (as per Xu et al, 2002):
- straight and vertical anterior margin of the antorbital fenestra
- frontal has a vertical lamina boardering the lacrimal
- surangular T-shaped in cross-section
- prominent lateral cnemial crest continuous with the fibular crest
Like some dromaeosaurids and avialans but unlike derived troodonts, S. changii has
- slender caudal process of the premaxilla, excluding the maxilla from the external naris
- postorbital process of the jugal long, slender, and posteriorly oriented
- lack of developed subotic recess
- Parabasisphenoid not greatly enlarged
- sacral count is five, with middle sacrals being wider than those on either side
- ilium less than 60% femoral length
- mildly opisthopubic
- MT III is subarctometatarsalian like Sinornithosaurus, not fully arctometatarsalian
