Benthopectinidae Verrill, 1894

Gale, Andy S. & Jagt, John W. M., 2021, The fossil record of the family Benthopectinidae (Echinodermata, Asteroidea), a reappraisal, European Journal of Taxonomy 755, pp. 149-190 : 174

? Benthopectinidae Verrill, 1894 Fig. 6A–B, F

? Benthopectinidae Verrill, 1894: 217 .

Material

Seventeen marginal ossicles; the inferomarginal figured ( Fig. 6A ) is MHI 2183/7; the other inferomarginal and oral ossicle illustrated here are MHI 2183/8 and 9. All are from the Maantang Formation (Carnian, Upper Triassic; sample C30) at Jiancougou, Sechuan Province, China.

Description

The inferomarginal and oral ossicles are strongly reminiscent in shape and external sculpture of those of benthopectinids; compare Fig. 6A–B with benthopectinid marginals ( Fig. 6C–E ), and the oral ( Fig. 6F ) with those of benthopectinids ( Fig. 6G–I ).

The inferomarginals share a number of similarities to those of benthopectinids ( Fig. 6A–E ), notably the coarse, longitudinally arranged rows of rugosities, the presence of a large spine (or pedicellaria) base close to the abactinal margin of the plate, and the marked asymmetry of the distal inferomarginals, in which the distal height is less than the proximal one. The oral ossicles ( Fig. 6F ) are remarkably similar to those of benthopectinids in the evenly convex actinal margin, the distally angled apophyse and the shape of the adambulacral articulation ( Fig. 6G–I ). However, the material available to date is too limited, and in the absence of ambulacrals and adambulacrals, this referral is very tentative.

Figures

Fig. 6 (next page). A–B, F.? Benthopectinidae. A–B. Inferomarginals, in lateral aspect (MHI 2183/7, MHI 2183/8). F. Oral ossicle in radial view (MHI 2183/9). — C, G. Jurapecten hessi Gale, 2011. C. Inferomarginal, in lateral view (NHMUK PI EE 17988). G. Oral ossicle, in radial view (NHMUK EE 13606; the original of Gale 2011a: pl. 20 fig. 10). — D–E, H. Pontaster tenuispinus (von Düben & Koren, 1846).D–E. Lateral view of inferomarginals.H. Oral ossicle (A.S. Gale collection, unregistered). — I–U. Jurapecten infrajurensis sp. nov. I. Oral ossicle, radial view (SNSB-BGSP2020XLV 31). J–M. Ambulacral ossicles, in actinal views (J = holotype, NHMUK PI EE 17989; K–L = paratypes, NHMUK PI EE 17990–17991; M = SNSB-BGSP2020XLV16). N–O. Marginal ossicles (paratypes, NHMUK PI EE 17992–17993). P, R–T. Adambulacral ossicles (paratypes), in actinal (P, R) and abactinal (S–T) views (R–S = NHMUK PI EE 17994–17995; P, T = SNSB-BGSP2020XLV 17, SNSB- BGSP2020XLV 19). I, Q. Oral ossicles, in radial view (paratypes: SNSB-BGSP2020XLV 15, SNSB- BGSP2020XLV 18). U. Circumoral ossicle (paratype: SNSB-BGSP2020XLV 20). Provenance: A–B, F. Maantang Formation (Carnian, Upper Triassic), sample C30, Jiancougou, Sechuan Province, China. C, G. Upper Oxfordian (Couches d’Effingen, bifurcatus ammonite Zone, stenocycloides ammonite Subzone), Savigna, near Orgelet, Département du Jura, France (Gale 2011b). D–E, H. Recent, Porcupine Trough, NE Atlantic. I, M, P–Q, T–U. Upper Toarcian–lower Aalenian (possibly aalensis ammonite Zone), Quedlinburg (Landkreis Harz, northern Germany; Hess 2014). J–L, N–O, R–S. Middle Toarcian, Le Clapier (Département d’Aveyron), 62 km WNW of Montpellier, southern France (Thuy 2012). See Fig. 3 for detailed morphological terminology. Scale bars: A–H = 0.4 mm; I–U = 0.2 mm.