Genus: Dinosauriformes gen. sp. indet. 2 (Long, and Murry, 1995)

Classification: Archosauria - Dinosauromorpha - Dinosauriformes

Species: none

Referred Specimens: UCMP177317, MNA V3091 (inorrectl listed as V2777): Dorsal vertebrae.
UCMP 138591, 178047, 178048, 178049: Sacral vertebrae.
UCMP 25793: Distal left tibia.
UCMP 25834: Distal femur.
UCMP 25820: Distal tibia.

Time: Adamanian, Late Carnian, Late Triassic.

Horizon: Bluewater Creek Formation, Lower Chinle Group.

Location: Placerias quarry (UCMP A269, MNA 207C), Big Hollow Wash near Romero Springs, a small valley 6 1/2 miles (approximately 10.4 km) of St. Johns, Apache County, Arizona, USA.

Total length:

Mass:

Diagnosis:

Comments: None of the dorsal vertebrae figured by Long & Murry (1995) (UCMP 177317, MNA V3091 [incorrectly listed as V2777 in Long & Murry 1995]) are diagnostic – they are equally comparable to many dinosauriforms as well as Shuvosaurus. The same is true for the sacral vertebrae (UCMP 138591, 178047, 178048, 178049) figured and listed by Long & Murry (1995). The distal left tibia (UCMP 25793) that Long & Murry (1995) refer to ‘?Prosauropoda indet.’ is not quadrangular in ventral view as present in Saturnalia, other basal sauropodomorphs and Coelophysis bauri, but is very similar to Silesaurus, Eoraptor and Herrerasaurus in possessing a posterolateral process of the distal tibia that has an unexpanded distal tibial margin that is convex in distal view. Therefore, we refer UCMP 25793 to Dinosauriformes indet. An unpublished distal femur from the Placerias Quarry (UCMP25834), although similar to a Shuvosaurus-like taxon distal femora, is referable to Dinosauriformes indet. on the basis of a fibular groove that opens at an obtuse angle and a rounded fibular condyle. This is identical to the distal femur morphologies of Silesaurus, Herrerasaurus, basal sauropodomorphs and coelophysoids. A second unpublished specimen from the Placerias Quarry (UCMP 25820) is a distal tibia. Although broken, it has a well-developed descending posterolateral process, a concave posterolateral margin in distal view and a well developed dorsal excavation for insertion of the ascending process of the astragalus. These features, in combination with a posterolateral process that extends well beyond the body of the tibia laterally, allow us to refer this specimen to Theropoda indet. It is possible that these two elements belong to ‘Camposaurus.’ (Nesbitt et al., 2007).

Illustrations:
Dinosauriformes gen. sp. indet. 2 UCMP177317, MNA V3091, dorsal vertebra in ventral (M), dorsal (N), lateral (O) and anterior (P) views (from Long & Murry, 1995).

References:

Long, R. A., and Murry P. A., 1995, Late Triassic (Carnian and Norian) Tetrapods from the Southwestern United States: New Mexico Museum of Natural History & Science, A Division of the Office of Cultural Affairs, Bulletin 4, p. 1-254.

Nesbitt, S. J., Irmis, R. B., and Parker, W. G., 2007, A critical re-evaluation of the Late Triassic Dinosaur Taxa of North America: Journal of Systematic Palaeontology, v. 5, n. 2, p. 209-243.

© Tetrapoda Database Roman Ulansky roman.ulansky@gmail.com or adios85@mail.ru