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.
Marasuchus
Until 2003 "Marasuchus" was thought to be one of the closest relatives of the dinosaurs. At present it has been supplanted by other dinosauromorphs such as "Silesaurus". Nonetheless, "Marasuchus" remains an important animal for understanding the origin and evolution of dinosaur characteristics. The following is a 
cladogram of basal Dinosauriformes according to Nesbitt (2011), and Dinosauria according to Baron "et al." (2017):
Alfred Romer first discovered fossils of the species in the 1960s in the Chañares Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina, all parts of the reptile’s skeletal anatomy are known from fossils except for the skull and lower jaw. The formation was dated as being 235 to 234 million years old.