Sinosauropteryx prima Ji and Ji, 1996

Rauhut, Oliver W. M., 2003, The interrelationships and evolution of basal theropod dinosaurs, Special papers in palaeontology 69, pp. 1-213 : 31

Sinosauropteryx prima Ji and Ji, 1996

Age . Barremian.

Occurrence. Yixian Formation, Liaoning, China.

Diagnosis. Tail with more caudal vertebrae (64) than any other known theropod; ungual of the first manual digit subequal in length to radius.

Remarks. Sinosauropteryx is known from three articulated specimens from the Early Cretaceous Yixian Formation of China. Unfortunately, the bone preservation is rather poor, so many anatomical details cannot be seen. However, the taxon is of great interest since it preserves integumentary structures that may be proto-feathers ( Chen et al. 1998; Unwin 1998). Thus, its systematic position is of importance, because it might indicate when an insulatory body cover evolved in theropods.