Sinosauropteryx
Three specimens have been assigned to "Sinosauropteryx prima": the holotype GMV 2123 (and its counter slab [opposite face], NIGP 127586), NIGP 127587, and D 2141. Another specimen, IVPP V14202, was assigned to the genus but not to the only species by Zhang and colleagues. The assignment of an additional larger specimen to "S. prima", GMV 2124, was later found to be in error. All of the fossils were found in the Jianshangou or Dawangzhangzi Beds of the Yixian Formation in the Beipiao and Lingyuan regions of Liaoning, China. These fossil beds have been dated to 124.6–122 million years ago, during the early Aptian stage of the Early Cretaceous.
Sinosaurus
Shaojin Hu (1993) assigned specimen KMV 8701 to "Dilophosaurus sinensis". In 2013, a study by Currie et al., confirmed that "D. sinensis" was the same animal as "Sinosaurus triassicus" On the other hand, Wang "et al." (2017) stated that it needs to be further investigated whether "D. sinensis" is indeed a junior synonym of "S. triassicus", and noted that the two species are different at least in the anatomy of the premaxilla. The authors tentatively assigned "D. sinensis" to the genus "Sinosaurus", but retained it as a species distinct from "Sinosaurus triassicus". Specimen KMV 8701 consists of a skull (measuring 525 mm), and is nearly complete. The specimen KMV 8701 is about long, meaning "Sinosaurus" was about that length. KMV 8701 has been assigned now to "Sinosaurus", but the specimen still lacks sufficient description and preparation. In 2012, a new specimen of "Sinosaurus" was described, and was found to represent a new species.