[D] Sinovenator changii [Su] [sG] [T]
Xu, Norell, Wang, Makovicky & Wu, 2002
Saurischia Theropoda Tetanurae Coelurosauria Maniraptora Troodontidae
Yixian Formation, [Jiufotang Formation], Lujiatun and Yanzigou, Shanyuan, Liaoning, China
< 1 meter
Genus - Typespecies - Skull
(Meeman Chang\\\\\\\'s China hunter) Based on a partial skull and skeleton and a referred skeleton from the lowest part of the Yixian Formation. Sinovenator changii is more basal or primitive than any other known troodontid .
The specific name honours Meeman Chang of the IVPP for her significant role in the study of the Jehol fauna\\\\\\\"
This taxon has several features that are not found in more derived troodontids, but that occur in dromaeosaurids and avialans. The discovery of Sinovenator and the examination of character distributions along the maniraptoran lineage indicate that principal structural modifications toward avians were acquired in the early stages of maniraptoran evolution. The foot resembles more closely the subarctometatarsalian condition seen in the basal dromaeosaurid Sinornithosaurus than the non-arctometatarsalian condition.
IVPP (Institute of Vertebrate Paleontology and Paleoanthropology,Beijing) V 12615, a disarticulated partial skull and skeleton. Referred specimen. IVPP V12583, an incomplete, articulated postcranial skeleton.
Diagnosis of genus (as for the type species): Troodontid having the following derived characters: straight, vertical rostral margin of antorbital fenestra; frontral havingvertical lamina bordering lacrimal; surangular T-shaped in cross section; prominent cnemial crest continious with fibular crest (Xu, Norell, Wang, Makovicky and Wu, (2002)