Pseudoconocrinus doncieuxi subsp. suboblongus Roux & Martinez & Vizcaïno 2021, n. subsp.
Creators: name: Roux, Michel
name: Martinez, Alain
name: Vizcaïno, Daniel
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Crinoidea
Comatulida
Rhizocrinidae
Pseudoconocrinus
Pseudoconocrinus doncieuxi
Pseudoconocrinus doncieuxi suboblongus

description: Pseudoconocrinus doncieuxi suboblongus n. subsp.
Figs. 8A–F, 9
Type-material. Holotype (MNHN.F. A81998; Fig. 8A–C, Plaziat Collection), from Fontcouverte (à l’Estagnol); paratype A (MNHN.F. A81999; Fig. 8D–E), from Fontcouverte (Lavade); paratype B (MNHN.F. A81999; Fig. 8F) from Montlaur (Réqui).
Etymology. In reference to the oblong shape of the aboral cup.
Material examined. In addition to the type series, 10 aboral cups from the Tuilerie de Fontcouverte (in UCB-FSL 170248 b, and Martinez Collection); 125 aboral cups and 238 columnals from Réqui, some aboral cups and columnals from other sites (see Table 2) in the Martinez and Vizcaïno collections.
Diagnosis. Variety with often very elongated aboral cup, Hc up to 155 mm, H/D most often> 2.5 and sometimes up to 5.7, Dc maximum located in central or adoral third, aboral third in inverted truncated cone with base corresponding to stalk insertion, adoral third truncated conical or subcylindrical in shape, distal face of radial circlet almost flat with marked star-shaped central depression in largest specimens, stalk insertion wide (Dp/Dr>050), columnals usually without marked bulge at mid-height.
Description. Quantitative characters of the three aboral cups of the type series listed in Table 3. Holotype: aboral cup with maximum Dc in central swollen third (Fig. 8A); adoral third in truncated cone, distal surface flat entirely occupied by insertion of arms, strongly star-shaped central cavity (Fig. 8B); aboral third in inverted truncated cone with flat base entirely occupied by stalk insertion housing proximalmost discoid columnals (Fig. 8C). Paratype A: aboral cup similar in shape to holotype but more elongated (H/D 2.5) and illustrating general trend of aboral cups from the Lavade and Requi sites (Fig. 8D–E). Paratype B: exceptionnally well-preserved, almost flat adoral face showing moderately protruding interradial ridges, with large, slightly star-shaped central cavity, and aboral and inner ligament areas of synarthries better developed than muscular areas (Fig. 8F).
Tables 5 and 6 list the general quantitative characters of aboral cups and columnals from the Réqui site where this variety strongly predominates; these specimens display a much smaller size than those of P. doncieuxi from the Tuilerie de Fontcouverte and a tendency towards greater and earlier elongation (Hc/Dc from 2.5 to 5.73 for 1.7<Dc<3.0 mm) (Fig. 8).
Remarks. Pseudoconocrinus doncieuxi suboblongus n. subsp. is present at numerous sites, but with widely varying frequencies. In the particular environment of Réqui (see above), this variety strongly predominates in several of the marl layers sampled. Aboral cups with Dc> 1.7 mm have a much less variable shape than those with Dc>2.5 from the Tuilerie de Fontcouverte (Fig. 9). This suggests a tendency for elongation during ontogeny that was channeled by environmental factors early during growth. At Réqui, the absence of brachials and rhizoid segments, the abnormal relative abundance of aboral cups compared to columnals (about 3 columnals per 1 aboral cup), as well as the poor preservation due to attrition and biocorrosion indicate a displacement of the ossicles that does not allow us to estimate average stalk length.
Occurrence. Early Ypresian (middle Ilerdian, NP 10–11), Corbières.
description: Published as part of Roux, Michel, Martinez, Alain & Vizcaïno, Daniel, 2021, A diverse crinoid fauna (Echinodermata, Crinoidea) from the Lower Eocene of the Gulf of Languedoc (Corbières, Aude, southern France), pp. 201-242 in Zootaxa 4963 (2) on pages 218-219, DOI: 10.11646/zootaxa.4963.2.1, http://zenodo.org/record/4700704