Bathycrinus undetermined
? Bathycrinus sp. Fig. 6A–B Material examined: one basal circlet (OPH210), two axillary brachial (IBr2ax) (OPH211). Description: Basals fused, aboral face slightly concave with an irregular radiate crenularium (Fig. 6A), adoral face convex slightly granulose without trace of pentagonal symmetry or nervous canal lumen and wide perilumen flat without granulation (Fig. 6B); adoral diameter 1.47 mm, aboral diameter 1.02 mm, height 1.91 mm. Axillary brachial (IBr2ax) with aboral surface smooth, adoral face poorly preserved having a marked axial groove (Fig. 6D), height 1.91 mm, maximum width 1.85 mm and proximal width 1.00 mm. Another similar but smaller IBr2ax with maximum width 1.30 mm. Remarks: The shape of the basal ring and the absence of a conspicuous lumen of interradial nervous canals on the adoral face is usual in Bathycrinus, which sometimes shows a discrete pentalobate figure like in B. carpenteri (Danielssen & Koren 1877) (Fig. 4C). The radiate crenularium on the basal ring adoral face or on the proximal columnal facets has never been observed in bathycrinids and rhizocrinids. Monachocrinus differs in having free basals with conspicuous interradial nervous canal open on adoral face (Roux, in preparation). The adoral face of IBr2ax resembles those of Monachocrinus (Fig. 6E), but unfortunately the material is too poorly preserved for a more conclusive comparison. Pending additional material, the two ossicles described above are attributed to? Bathycrinus sp.
Institutions
- Centre National de la Recherche Scientifique (FR)
- École Pratique des Hautes Études (FR)
- Sorbonne Université (FR)
- Institut de Systématique, Évolution, Biodiversité (FR)
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2025-02-04
- DOI
- https://doi.org/10.5281/zenodo.14852756
- Primary Topic
- Cephalopods and Marine Biology
- Type
- article
- Field-Weighted Citation Impact
- 0.00