Stereospondyli Zittel, 1888

Schoch, Rainer R., Fastnacht, Michael, Fichter, Jürgen & Keller, Thomas, 2007, Anatomy and relationships of the Triassic temnospondyl Sclerothorax, Acta Palaeontologica Polonica 52 (1), pp. 117-136 : 120

Stereospondyli Zittel, 1888

Capitosauria Schoch and Milner, 2000 Sclerothoracidae Huene, 1932

Sclerothorax Huene, 1932

Sclerothorax hypselonotus Huene, 1932

Lectotype: HLD−V 607 ( Fig. 1B ). Skull length 170 mm, total length of preserved parts of specimen 480 mm. The lectotype was designated by Fastnacht (2004).

Type locality: Sandstone quarry near Queck in the Fulda Valley (r: 35/41.525; h: 56/20.300).

Type horizon: Eichsfeld Sandstein, lower part of Middle Buntsandstein section (Volpriehausen Folge, S4), Olenekian, Lower Triassic ( Huene 1932; Laemmlen 1963; Fastnacht 2004).

Referred material.— HLD−V 608 and GPIM−N 2045 from the type locality at Queck, NMK−S 117 , 118 a, b from top of Hardegsen Sandstein (S 6) of Heimarshausen near Naumburg (see Appendix 1).

Stratigraphic range.—Lower (S4) to upper part (S6) of Middle Buntsandstein section, probably spanning a large part of the Olenekian, which equals 4–5 Ma (Deutsche Stratigraphische Kommission 2002).

Diagnosis.—Autapomorphic character−states, diagnosing S. hypselonotus from all other temnospondyls: (1) Skull very wide with quadrangular outline, anterior third of skull as wide as cheek, with convex lateral projections. (2) Margin of snout heavily ornamented by gross ridges that form high tubercles. (3) Medial skull roofing elements laterally extended, with frontals and parietals being as wide as long and postparietals being two times wider than long. (4) Neural spines differing in height, converging towards a highest point well anterior to the mid−level of the trunk ( Fig. 5 ). (5) Interclavicle extensive, longer than the skull and nearly as wide, thereby proportionately larger than in any other temnospondyl ( Fig. 1B ). (6) Glenoid area forming a prominent process that raises well from the lateral face of the scapulocoracoid ( Fig. 6D ). (7) Postcranium covered with numerous irregular and small, heavily ornamented ossicles ( Fig. 6H ).

Figures

Fig. 1. Original material of Sclerothorax hypselonotus Huene, 1932 described by Huene (1932) from Buntsandstein of Queck, Hessen, Germany. A. HLD−V 608, lateral view (right side). B. HLD−V 607 (lectotype) in dorsal view (B1) with interpretive drawing (B2).

Fig. 5. Sclerothorax hypselonotus Huene, 1932. A. Reconstruction of complete skeleton in lateral view (based largely on HLD−V 608, GPIM−N 2045). B. HLD−V 608, original material. B1, postcranial skeleton in right lateral view, exposing ribs and parts of the pectoral and pelvic girdle, B2 same skeleton in left lateral view. C. GPIM−N 2045, anterior trunk skeleton in left lateral view, exposing pleurocentra. D. Reconstruction of vertebrae in the mid−trunk region, based on GPIM−N 2045.

Fig. 6. Sclerothorax hypselonotus Huene, 1932. Postcranial skeleton, based on material from Queck and Heimarshausen, Middle Buntsandstein. A. Cervical region, with second and third vertebra exposed (HLD−V 608). B. Neural arches in ventral view (NMK−S 117; numbers mark position within column). C. Dermal elements of pectoral girdle in ventral view (based on HLD−V 607). D. Pectoral girdle as preserved (HLD−V 607) in lateral (D1) and posterolateral (D2) views. E. Right humerus (HLD−V 607). F. Left femur (NMK−S 118) in dorsal (F1) and posterior (F2) views. G. Right pelvis (HLD−V 608).H. Dermal ossicles.