Stormbergia

Butler, Richard J., 2005, The ‘ fabrosaurid’ ornithischian dinosaurs of the Upper Elliot Formation (Lower Jurassic) of South Africa and Lesotho, Zoological Journal of the Linnean Society 145 (2), pp. 175-218 : 188

CF. STORMBERGIA

SAM-PK-K1107

A partial postcranial skeleton of a basal ornithischian, SAM-PK-K1107 ( Figs 20–23 ), was collected from the same site as the holotype of Stormbergia (SAM-PK- K1105) by AW Crompton. It appears to represent an individual of roughly the same size as SAM-PK- K1105, based on the length of the femur ( Table 2). The large size of this specimen, and the presence of features (particularly of the humerus) that clearly distinguish it from Lesothosaurus (see below), suggest that SAM-PK-K 1107 may be referable to Stormbergia . However, referral of SAM-PK-K1107 is complicated by the lack of overlap of diagnostic elements between it and the holotype (SAM-PK-K1105) and paratype (BMNH R11000) specimens of Stormbergia . For example, an ischium is unknown in SAM-PK-K1107. The humerus of SAM-PK-K1107 is distinctive ( Fig. 23 ), yet is poorly known in SAM-PK-K1105 and BMNH R11000.

For these reasons, I do not herein refer SAM-PK- K1107 to Stormbergia , although further discoveries of Upper Elliot Formation ornithischians may allow that referral. The anatomy of SAM-PK-K1107 is described separately below.

Figures

Figure 20. cf. Stormbergia. SAM-PK-K1107: axis and atlas, right lateral view (A); atlantal intercentrum, dorsal view (B). Abbreviations: at int, atlantal intercentrum; gr od, groove, for odontoid process, on dorsal surface of atlantal intercentrum; od pr, odontoid process; pa, parapophysis; poz, postzygapophysis.

Figure 21. cf. Stormbergia. SAM-PK-K1107, anterior-mid dorsal series in right lateral view (A). These vertebrae have been articulated together as labelled by the preparator, and appear to fit reasonably well, but the original association is not known. SAM-PK-K1107, posterior dorsals, sacrum and anterior caudals in right lateral view (B). Abbreviations: cav, caudal vertebrae; di, diapophysis; ds, dorsosacral; pa, parapophysis; dv, posterior dorsals; pub, fragment of pubic shaft; sv2, sv3, sv4, sv5, ‘true’ sacral vertebrae, i.e. those vertebrae which have ribs which articulate with the ilium.

Figure 22. cf. Stormbergia. SAM-PK-K1107, reconstruction of posterior dorsals, sacrum and anterior caudals in articulation with the right ilium, to show positions of sacral rib attachment and probable incorporation of vertebrae into sacrum. The ancestral two sacrals are shown in dark grey, the caudosacral (sacral 5) is shown in light grey, the first dorsosacral (sacral 2) is cross-hatched and the second dorsosacral is shown with a fill of parallel, diagonally orientated lines. Matt black areas represent the attachment of the sacral ribs to the medial surface of the ilium. Labels refer to the vertebrae directly above them. Abbreviations: bs, brevis shelf; cav1, caudal 1; cs, caudosacral; ds1, ds2, dorsacrals 1 and 2; sv1, sv2, ancestral sacrals 1 and 2.

Figure 23. cf. Stormbergia. SAM-PK-K1107, photos of block of articulated material including portions of two anterior dorsals, rib fragments, left scapulocoracoid and left humerus. Humerus is exposed in anterolateral (A) and posteromedial (B) views. Abbreviations: ac, acromion process; adv, anterior dorsal; cor, coracoid; dpc, deltopectoral crest of the humerus; gl, glenoid; hum, humerus; scap, scapula.