Stauranderasteridae, Spencer, 1913

Gale, Andrew Scott, 2021, Taxonomy and phylogeny of the ‘ football stars’ (Asteroidea, Sphaerasteridae), Journal of Systematic Palaeontology 19 (10), pp. 691-741 : 702

? Stauranderasteridae

( Fig. 8G )

2011 possible stauranderasterid oral ossicle Gale: pl. 16, figs 10, 11.

Material. Two oral ossicles ( NHMUK EE 13584, MnhnL OPH 173) from the Carnian (Late Triassic) St. Cassian Formation, Cortina d’ Ampezzo, Italy.

Description. The two well-preserved oral ossicles ( Gale 2011, pl. 16, figs 10, 11; herein Fig. 8G ) possess convex actinal and distal margins of equal length, set at right angles. The external actinal surface bears a proximal row of fine os attachments, and five larger, irregularly distributed suboral spine (sos) are present. The distal surface for contact with the adamb (orada, oradm) is large and well developed. The apophyse (apo) is short and blunt.

Remarks. These oral ossicles are similar in shape to those of Sphaeraster (e.g. Fig. 8A–E ) and the stauranderasterid Manfredaster bulbiferus ( Forbes, 1848) ( Fig. 8N ) in that the tall proximal margin is set at right angles to the actinal margin. The triangular spine-bearing actinal surface is positioned on the lateral part of the ossicle, as in stauranderasterids, to which they are provisionally assigned. If this is the case, the origination of the Stauranderasteridae probably lies in the Middle Triassic.

Figures

Figure 8. Oral ossicles of sphaerasterids. A–E, Sphaeraster tabulatus (Goldfuss, 1833); A, D, interradial view of orals of smaller individuals (NHMUK EE 17642, 17643); B, E, interradial (B) and radial (E) views of small oral (NHMUK EE 17644); C, large oral, interradial view (NHMUK EE 17623b). F, I, Eosphaeraster amellagensis gen. et sp. nov., oral in interradial and radial views, respectively (NHMUK EE 17645). G, oral ossicle of possible stauranderasterid or sphaerasterid, interradial view (MnhnL OPH173). H, oral ossicle, probably from Bulbosphaeraster valettei gen. et sp. nov., interradial view (NHMUK EE 17646). J, L, oral ossicle of Podosphaeraster pulvinatus Rowe & Nichols, 1980, in interradial and radial views, respectively (MhnhL OPH174–176). K, M, oral ossicle of Valettaster argus (Spencer, 1907), in interradial and radial views, respectively (NHMUK EE 17637h). N, interradial view of oral ossicle of Manfredaster bulbiferus (Forbes, 1848) (NHMUK EE 17647a). Provenance: A–E are from the upper Oxfordian, Hypsilum ammonite Zone, Plettenberg, near Balingen, Germany. F, I are from the upper Pliensbachian, outcrop on south side of wadi immediately to west of road, 0.5 km south of the Kasbah of Amellago, Atlas Mountains, Morocco. G is from the Carnian (Upper Triassic), Cortina d’Ampezzo, Italy. H is from the lower Bathonian, Zigzagiceras zigzag ammonite Zone at La Pouza, near La Voulte-sur-Rhone, Ard̀eche, France. K, M, N are from the coranguinum Zone, Santonian, Broadstairs, Kent, UK. J, L are Recent, Philippines. Scale bars: A, D, G, H, K, M = 0.5mm; B, E = 0.2 mm; C, F, I, J, L, N = 1 mm.