Postosuchus kirkpatricki Long and Murry, 1995

Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, Bulletin of the American Museum of Natural History 2011 (352), pp. 1-292 : 38

CM 73372 5 Postosuchus kirkpatricki Long and Murry, 1995 ; Weinbaum, 2002; Novak, 2004; Peyer et al., 2008.

AGE: Late Norian–?Rhaetian, Late Triassic ( Heckert et al., 2008).

OCCURRENCE: Coelophysis Quarry , ‘‘siltstone member’’ of the Chinle Formation, Ghost Ranch, northern New Mexico.

SPECIMEN: CM 73372, articulated postcranial skeleton including hind limbs, pelvis, dorsal, sacral, and caudal vertebrae, portions of the humerus, scapula, ulna, radius, partial manus, osteoderms, ribs, and gastralia.

REMARKS: In a review of Postosuchus kirkpatricki, Long and Murry (1995) referred an articulated skeleton from the Coelophysis Quarry of New Mexico to P. kirkpatricki without specific justification. Weinbaum (2002), Novak (2004), and Peyer et al. (2008) accepted the identification of CM 73372 as P. kirkpatricki . Nevertheless, these authors failed to note any synapomorphies unique to P. kirkpatricki and CM 73372. All authors noted that the specimen represents a skeletally immature individual because none of the neural sutures are closed (see Brochu, 1996; Irmis, 2007). Weinbaum (2002) and Novak (2004) did note that the preacetabular process of the ilium was much longer than that of P. kirkpatricki .

Because there are no clear characters linking P. kirkpatricki to CM 73372 to the exclusion of other taxa, it is treated as a separate terminal taxon. CM 73372 differs from Postosuchus kirkpatricki and Rauisuchus in possessing a concave ventral margin of the ilium. Also, CM 73372 differs from P. alisonae in processing an asymmetrical distal end (in distal view) of metatarsal IV. CM 73372 and Polonosuchus overlap only in the caudal vertebrae, but do not differ.

KEY REFERENCES: Long and Murry, 1995; Weinbaum, 2002; Novak, 2004; Peyer et al., 2008.