Punkaster spinifera Gale & Jagt 2021, gen. et sp. nov.
Creators: name: Gale, Andy S.
name: Jagt, John W. M.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Asteroidea
Notomyotida
Benthopectinidae
Punkaster
Punkaster spinifera

description: 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).
description: Published as part of Gale, Andy S. & Jagt, John W. M., 2021, The fossil record of the family Benthopectinidae (Echinodermata, Asteroidea), a reappraisal, pp. 149-190 in European Journal of Taxonomy 755 on pages 168-172, DOI: 10.5852/ejt.2021.755.1405, http://zenodo.org/record/5032970