Sinosauropteryx
"Sinosauropteryx" was a small bipedal theropod, noted for its short arms, large first finger (thumbs), and long tail. The taxon includes some of the smallest known adult non-avian theropod specimens, with the holotype specimen measuring only in length, including the tail. However, this individual was relatively young. The longest known specimen reaches up to in length, with an estimated weight of .
Shuangbaisaurus
A further issue in the relation between "Shuangbaisaurus" and "Sinosaurus" involves the taxonomic convolution that has befallen "Sinosaurus". At least one species is recognized in the genus, "Sinosaurus triassicus", consisting of specimens LFGT LDM-L10 and LFGT ZLJT01; another specimen, KMV 8701, originally named "Dilophosaurus" "sinensis", has been referred to either "S. triassicus" or a second species "S. sinensis". KMV 8701 approaches "Shuangbaisaurus" more closely in its tall skull and premaxilla than specimens referred to "S. triassicus". Wang "et al." elected to retain "S. sinensis" as a separate species owing to these differences. No phylogenetic analysis has been conducted to quantitatively determine the relationships of "Shuangbaisaurus".