Bulbosphaeraster valettei Gale 2021, sp. nov.
Creators: name: Gale, Andrew Scott
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Asteroidea
Valvatida
Sphaerasteridae
Bulbosphaeraster
Bulbosphaeraster valettei

description: Bulbosphaeraster valettei sp. nov.
(Figs 6L, M, 8H, 19B, 20A–M)
Types. The primary interradial ossicle figured here is the holotype (Fig. 20B, NHMUK EE 17670); the other figured ossicles are paratypes (NHMUK EE 17671–17679).
Diagnosis. As for the genus.
Derivation of name. In honour of the late Dom Auŕelien Valette, who identified that the material belonged to a different genus and species, in his labels with the specimens in the Dijon collection.
Material. Two abactinal ossicles in the Valette Collection, Dijon (UdB, unregistered), 25 abactinal ossicles (NHMUK EE 17670–17679, 17703) from the Bathonian, Zigzagiceras zigzag ammonite Zone of La Pouza, near La Voulte-sur-Rhone (Ard̀eche, France).
Description. The species is known from primary abactinal ossicles that can be identified with reference to articulated material of Sphaeraster tabulatus (ce, pr, pir). All abactinal ossicles have a similar sculpture of evenly placed, rather widely spaced spine pits, each of which has a broad, raised, crater-like rim (Fig. 20A–M). The ossicles articulate by means of rectangular to oval surfaces centrally placed on each lateral surface, which are irregularly pitted (Fig. 20D, E). The pir are vertically symmetrical, heptagonal, slightly broader than tall, and carry an evenly rounded, bulbous swelling on the upper central part of the outer face (Fig. 20A, B, E). The swelling carries large, irregular spine pits and shows probable in vivo abrasion. The pr are hexagonal and rounded in outline, vertically symmetrical and gently swollen centrally (Fig. 20A). The proximal articular facet is broader than the distal one. The ce (Fig. 20L) is equilaterally pentagonal and gently convex, and the proximal margin carries a rounded notch for the periproct. Each side carries two to four papular notches concentrated at the corners (Fig. 20C). Possible ico ossicles (Fig. 20C) are pentagonal with a dense cover of spine pits. Distal abactinal ossicles (Fig. 20G) are broad and concavo-convex. The position of other abactinal ossicles figured (Fig. 20F, H, J, L, M) is uncertain, but they all share the same distinctive sculpture. Ambulacrals (Fig. 6L, M) are short and broad, with a straight basal margin, and the padam and dadam sites are positioned on the lateral surfaces. A single oral ossicle (Fig. 8H) is tall, and the apophyse is directed proximally; the oradam is tall and narrow.
Remarks. Bulbosphaeraster gen. nov. can be distinguished from its closest relative, Eosphaeraster gen. nov., by the swollen central areas on the pr and pir, the triplet of papular openings at each triple plate boundary (there are up to 12 in Eosphaeraster gen. nov.) and the nature of the articulation of the distal abactinal ossicles. In Bulbosphaeraster gen. nov. the articulations are proximally imbricating and possess a single central articular facet. In Eosphaeraster gen. nov. they consist of vertical articular bars separated by papular notches. Ambulacrals, adambulacrals and orals are similar. The crater-rimmed spine pits present on all abactinal/actinal ossicles are found only on actinal ossicles of other sphaerasterids (Figs 9E, 15A, B).
description: Published as part of Gale, Andrew Scott, 2021, Taxonomy and phylogeny of the ' football stars' (Asteroidea, Sphaerasteridae), pp. 691-741 in Journal of Systematic Palaeontology 19 (10) on pages 718-719, DOI: 10.1080/14772019.2021.1960911, http://zenodo.org/record/10949919