Bulbosphaeraster valettei, Gale, 2021
publication ID |
https://doi.org/ 10.1080/14772019.2021.1960911 |
publication LSID |
lsid:zoobank.org:pub:F8991F09-B5FB-40EF-B4CC-474D925085B8 |
DOI |
https://doi.org/10.5281/zenodo.10955111 |
persistent identifier |
https://treatment.plazi.org/id/B9207C41-9A6A-FFE4-0CC8-FD7BFD98FDA5 |
treatment provided by |
Felipe |
scientific name |
Bulbosphaeraster valettei |
status |
sp. nov. |
Bulbosphaeraster valettei View in CoL sp. nov.
( Figs 6L, M View Figure 6 , 8H View Figure 8 , 19B, 20A–M View Figure 20 )
Types. The primary interradial ossicle figured here is the holotype ( Fig. 20B View Figure 20 , NHMUK EE 17670 About NHMUK ); the other figured ossicles are paratypes ( NHMUK EE 17671–17679 About NHMUK ) .
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 View Figure 20 ). The ossicles articulate by means of rectangular to oval surfaces centrally placed on each lateral surface, which are irregularly pitted ( Fig. 20D, E View Figure 20 ). 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 View Figure 20 ). 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 View Figure 20 ). The proximal articular facet is broader than the distal one. The ce ( Fig. 20L View Figure 20 ) 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 View Figure 20 ). Possible ico ossicles ( Fig. 20C View Figure 20 ) are pentagonal with a dense cover of spine pits. Distal abactinal ossicles ( Fig. 20G View Figure 20 ) are broad and concavo-convex. The position of other abactinal ossicles figured ( Fig. 20F, H, J, L, M View Figure 20 ) is uncertain, but they all share the same distinctive sculpture. Ambulacrals ( Fig. 6L, M View Figure 6 ) 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 View Figure 8 ) 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 View Figure 9 , 15A, B View Figure 15 ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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