Aetosaurus ferratus Fraas, 1877

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 : 23

Aetosaurus ferratus Fraas, 1877

AGE: Norian, Middle Keuper, Late Triassic (see Schoch, 2007).

OCCURRENCE: Lower Stubensandstein, Löwenstein Formation, southwest of Stuttgart, Germany.

LECTOTYPE: Specimen 16 (XVI), a nearly complete skull and postcranium that is part of the SMNS 5770 cluster, an assemblage of at least 25 specimens.

REFERRED MATERIAL: SMNS 5771 (type locality and horizon), SMNS 18554 (articulated skeleton lacking skull and pectoral girdle; Blankenhorn Castle near Eibensbach); Middle Stubensandstein from Pfaffenhofen: SMNS 11837 (type of A. crassicauda ), SMNS 12670 (collection of isolated dorsal plates and a fragment of the ventral osteoderms); SMNS 14882 (articulated tail portion with osteoderms and 14 caudal vertebrae).

REMARKS: Aetosaurus was named by Fraas (1877) from an accumulation of at least 24 individuals that lie in almost complete articulation. Although Aetosaurus is known from well-preserved articulated material, the extensive osteoderm carapace or other skeletal elements conceal details of the vertebrae, braincase, palate, and pectoral and pelvic girdles. A detailed and useful review of the taxon by Schoch (2007) provided additional information on the skull, variation, and osteoderms. Even though specimens from outside the Lower Stubensandstein have been referred to Aetosaurus ( Jenkins et al., 1994; Heckert and Lucas, 1998; Small, 1998) only the individuals numbered SMNS 5770 are scored here.

KEY REFERENCES: Fraas, 1877; Huene, 1920; Walker, 1961; Wild, 1989; Schoch, 2007.