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.
Sinosaurosphargis
"Sinosaurosphargis" was first described and named by Chun Li, Olivier Rieppel, Xiao-Chun Wu, Li-Jun Zhao and Li-Ting Wang in 2011 and the type species is "Sinosaurosphargis yunguiensis". The generic name is derived from Greek "sino", meaning "China", "sauros", meaning "lizard", and "sphargis", the old genus name for the leatherback turtle, (in reference to the many similarities "Sinosaurosphargis" shares with "Saurosphargis", a taxon whose holotype was lost and was thus considered a mystery), following the pattern of "Sinosauropteryx". Like the name of "Saurosphargis" itself, it also refers to "Sinosaurosphargis"' dorsal osteoderm "body armor" and broadened ribs forming a closed chest rib basket - traits which are seemingly transitional between turtles and other reptiles. The specific name "yunguiensis" is derived from the names of the neighboring Yunnan and Guizhou Provinces, where the fossils were found.