Punkaster spinifera, Gale & Jagt, 2021

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 : 168-172

Punkaster spinifera gen. et sp. nov.

urn:lsid:zoobank.org:act:89D1989C-BB8C-459E-84D4-40874052C57C

Figs 9–11, 12J–K

Zwischenplatten QA, RA – Müller 1953: 45, pl. 10 figs qa–ra.

indeterminate “cryptozonid” – Jagt 1999: pl. 2 figs 1–2, 4.

benthopectinid sp. 2 – Jagt 2000: 394, pl. 6 figs 5–6, 8, 10–12, pl.7 figs 1–2.

Diagnosis

Punkaster gen. nov. in which the marginal ossicles carry 1–2 cylindrical spine bases, which bore conical spines.

Etymology

Derived from the Latin ‘ spinifera ’, meaning bearing spines.

Material examined

A set of>100 associated ossicles (marginals, a single terminal, abactinals, actinals, orals, circumorals, odontophores, adambulacrals, ambulacrals, marginal spines, adambulacral spines and oral spines) from ca 12 metres below the Cretaceous-Paleogene (K/Pg) boundary in the upper Maastrichtian Højerup Member (Tor Formation; Surlyk et al. 2006) at Kulsti Rende, Stevns Klint, eastern Denmark, is the holotype ( NHMM JJ 11736 ). Additional material includes disarticulated, yet associated, ossicles of another individual from the same locality and stratigraphical unit, as well as isolated marginal ossicles from several localities exposing Cenomanian–Maastrichtian rocks in the United Kingdom (Kent, Hampshire), Belgium, Germany (Rügen, SNSB-BGSP collections; Aachen area) and the Czech Republic, including ossicles from the lower Campanian Chalk of Downend, Hampshire ( Gale 1980).

Description

Marginals are highly distinctive plates; supero- and inferomarginals elongated, broadly rectangular in lateral-abactinal aspect, with a length-parallel central rounded ridge, single oninferomarginals, bifurcating towards distal and proximal margins of superomarginals. Central, raised part of ridge carrying 2–3 spine bases, borne on cylindrical protrusions projecting from surface of ossicles. Superomarginals ( Fig. 9E, I, P ) with thin, narrow abactinal portion and opposing inferomarginals. Inferomarginals ( Fig. 9J, M ) with distinctive facet on internal surface for contact with adambulacrals. External surface of supero- and inferomarginals with complex sculpture comprising numerous small, rounded rugosities interconnected by network of stereom. Marginal spines ( Fig. 10D–E ) conical, thorny.

Adambulacrals boot-shaped in actinal and abactinal aspect, large adp forming heel, narrow distal extension ( Fig. 10A, H ); adradial margin deeply concave to accommodate large tube feet. Three to four attachment sites for fs, sads not present; probable fs large, lanceolate ( Fig. 9A–D ). Abactinal surface ( Fig. 11D ) of adambulacrals showing ada3 on abradial margin, poorly defined ada2. Ambulacrals ( Figs 9H, Q–R , 10J–M ) in proximal position ( Fig. 10J ) short, broad, distal ambulacrals with elongated ambh ( Fig. 10L ). Abactinal ridge present ( Fig. 10M ). Ambulacrals ( Figs 9Q–R , 10K , 11C ) with separate wing for padam, ada3 on abradial margin, dadam large, ada2 poorly defined, ada1 large. Oral ossicles robust, subtriangular, actinal surface trapezoidal, concave centrally ( Fig. 10P ). Proximal margin with three oral spine bases and two suboral spine bases on distal margin; apo stout, with shallow rng.

Abactinal ossicles flattened parapaxillae, with irregular lobed outlines and bevelled rim ( Fig. 9F–G, S ). Raised central area with finely rugose stereom which probably carried small spines. Some abactinals with single, outwardly directed spine base.

Remarks

Punkaster spinifer gen. et sp. nov. differs from P. ruegenensis gen. et sp. nov. (see below) in the unfused proximal supero- and inferomarginals and in the presence of large marginal spine bases. As seen in our reconstruction ( Fig. 11 ), the marginals were paired, not alternating, and carried a transverse fan of 4–6 outwardly directed, large conical thorny spines ( Fig. 11A ). The species had very large tube feet, protected by large, lanceolate furrow spines ( Fig. 11B ).

Figures

Fig. 9. Punkaster spinifera gen. et sp. nov. (holotype, NHMM JJ 11736). A–D. Subadambulacral or suboral spines. E, I–J, M, P. Marginal ossicles. F–G, S. Abactinal ossicles. H, Q–R. Ambulacrals, in actinal view. K. Circumoral, in actinal view. L, N. Odontophore, in abactinal and actinal views. O. Oral ossicle, in radial view. Provenance: uppermost Maastrichtian, ca 12 m below K/Pg boundary, Kulsti Rende, Stevns Klint, eastern Denmark. Scale bars: A–D = 5 mm; E–S = 1 mm.

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.

Fig. 7 (next page). A–J. Jurapecten infrajurensis sp. nov., various ossicle types (paratypes). A, H. Ambulacrals, in lateral and actinal aspects, respectively (SNSB-BGSP2020XLV 21,SNSB- BGSP2020XLV 28). B, E–F. Adambulacrals, in actinal and abactinal views (SNSB-BGSP2020XLV 22, SNSB-BGSP2020XLV 25–26). C, G, J. Superomarginals, in lateral views (SNSB-BGSP2020XLV 23, SNSB-BGSP2020XLV 27, SNSB-BGSP2020XLV 30). D, I. Inferomarginals, in lateral views (SNSB-BGSP2020XLV 24, SNSB-BGSP2020XLV 29). — K–Y. Jurapecten hessi Gale, 2011. K, P, U. Adambulacral ossicles. K. Abactinal view (NHMUK PI EE 17996). P. NHMUK EE 13598 (the original of Gale 2011a: pl. 19 fig. 11). U. NHMUK EE 13599, the original of Gale (2011a: pl. 20 fig. 12). L. Circumoral ossicle (NHMUK EE 13605, the original of Gale 2011a: pl. 20 fig. 13). M–N. Ambulacral ossicles, in actinal and abactinal views, respectively (NHMUK EE 13595–13596, the originals of Gale 2011a: pl. 19 figs 8–9). O. Ambulacral, in proximal/distal view (NHMUK 13597). Q–S. Superomarginal ossicles (NHMUK EE 13601–13602; the originals of Gale 2011a: pl. 20 figs 6–7). T, V–W. Inferomarginals (NHMUK EE 13600, EE 13603–13604, EE 13608, the originals of Gale 2011a: pl. 20 figs 5, 8, 16). X–Y. Oral ossicles (NHMUK EE 13606– 13607, the originals of Gale 2011a: pl. 20 figs 10, 14). Provenance: A–J. Upper Toarcian–lower Aalenian (possibly aalensis ammonite Zone), Quedlinburg (Landkreis Harz, northern Germany; see Hess 2014). K–Y. Upper Oxfordian (Couches d’Effingen, bifurcatus ammonite Zone, stenocycloides ammonite Subzone), Savigna, near Orgelet, Département du Jura, France (Gale 2011b). Abbreviations: d = distal; p = proximal. See Fig. 3 for detailed morphological terminology. Scale bars: A–J = 0.2 mm; K–Y = 0.5 mm.