Prestosuchus chiniquensis Huene, 1938

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 : 32-33

Prestosuchus chiniquensis Huene, 1938

AGE: Middle Triassic ( Schultz et al., 2000). OCCURRENCE: Weg sanga, Santa Maria 1 sequence, Santa Maria Formation, Brazil.

HOLOTYPE: BSP XXV 1-3/5-11/ 28-41/49, splenial, anterior portion of the surangular, anterior portion of the angular, prearticular, right partial maxilla, fragmentary dentary, three incomplete cervical vertebrae, fragmentary ribs, one sacral vertebra, two sacral ribs, five anterior caudal vertebrae with chevron bones, 14 middle and posterior caudal vertebrae, right and left scapulocoracoid, interclavicle and clavicle, distal left humerus, right proximal and distal humerus, distal radius, fragmentary ulna, one manual phalanx, incomplete ilium, fragmentary ischia, pubes, and complete left hind limb (including femur, tibia, fibula, ankle, and pes).

REMARKS: Huene (1938) named Prestosuchus chiniquensis for a mandible and cranial fragments and much of a postcranial skeleton. For the most part, P. chiniquensis was assigned to ‘‘Rauisuchia’’; furthermore, Parrish (1993) found a clade containing P. chiniquensis , Ticinosuchus , and Saurosuchus . Desojo and Rauhut (2008) presented the following two autapomorphies of P. chiniquensis : anterior notch between the scapula and coracoid and longitudinal ridge on the dorsal surface of the ischium. Only the holotype is scored here for this terminal taxon.

KEY REFERENCES: Huene, 1938, 1942; Parrish, 1993; Desojo and Rauhut, 2008.

UFRGS 0156-T

AGE: Ladinian, Middle Triassic, Therapsid assemblage zone ( Schultz et al., 2000).

OCCURRENCE: Rosario do Sul, Santa Maria Formation, near Candelaria City, Brazil.

REFERRED MATERIAL: Complete skull, much of the presacral axial column, articulated osteoderms.

REMARKS: UFRGS 0156-T is a very large skull (88 cm) that was assigned to Prestosuchus chiniquensis by Barberena (1978) and more recently by Azevendo (1991). Parrish (1993) separated UFRGS 0156-T from P. chiniquensis in his phylogenetic analysis and found that no character scores separated the two. Thus, he combined the two in his final hypothesis. I separate P. chiniquensis and UFRGS 0156-T as terminal taxa. P. chini- quensis and UFRGS 0156-T are both from a similar stratigraphic position near the bottom of the Santa Maria sequence. Parrish (1993) scored characters of the calcaneum and pes of UFRGS 0156-T, but these elements are absent in UFRGS 0156-T.

KEY REFERENCES: Barberena, 1978; Azevendo, 1991; Parrish, 1993.

UFRGS 0152-T

AGE: Middle to Late Triassic.

OCCURRENCE: Santa Maria sequence (see below).

REFERRED MATERIAL: Maxillae, nasals, quadrate, partial quadratojugal, complete braincase, parietal, ectopterygoid, partial pterygoid, jugal, squamosal, anterior portion of the dentary, prearticular, articular, cervical, dorsal, sacral, and caudal vertebrae, osteoderms, scapula, coracoid, humerus, proximal portion of the ulna, complete pelvic girdle, femora, tibia, fibula, calcaneum, pes, chevrons.

REMARKS: UFRGS 0152-T consists of an undescribed archosaur that possesses overlapping elements with both UFRGS 0156-T and Prestosuchus chiniquensis . Furthermore, UFRGS 0152-T is indistinguishable from UFRGS 0156-T and Prestosuchus chiniquensis . Even though the exact locality is not known, it was collected from the Santa Maria sequence.