A diverse crinoid fauna (Echinodermata, Crinoidea) from the Lower Eocene of the Gulf of Languedoc (Corbières, Aude, southern France) Author Roux, Michel Muséum national d’Histoire naturelle, UMR 7205 ISYEB MNHN-CNRS-UPMC-EPHE, Département Systématique et Évolution, CP 51, 57 rue Cuvier, 75231 Paris Cedex 05, France Author Martinez, Alain Chemin de Saint Estève, 11200 Lézignan-Corbières. France Author Vizcaïno, Daniel 7 rue J. - B. Chardin Maquens, 11000 Carcassonne, France text Zootaxa 2021 2021-04-19 4963 2 201 242 journal article 7139 10.11646/zootaxa.4963.2.1 049b6936-13d8-42d6-9468-2019ddf78d14 1175-5326 4700704 ACEC045B-AEE7-43FB-A074-D2AD6CB40F1D Family Rhizocrinidae Jaekel, 1894 Remarks. The distal face of the radial circlet ( Fig. 2B ) and the presence or absence of axillary brachials ( Fig. 2D ) have been shown to be highly useful for distinguishing the various rhizocrinid genera ( Roux et al . 2019 ). Those authors subdivided Conocrinus (sensu lato) into three genera, namely Conocrinus (sensu stricto), Paraconocrinus and Pseudoconocrinus . Although appearing as early as the Ypresian, Conocrinus (sensu stricto) was not found in Ilerdian strata of Corbières. The proximal columnals that constitute the proxistele of rhizocrinids are more or less thick and disc shaped, usually with flat and smooth facets. They are rare or absent in the screen-washed residues that we picked by hand. The columnals of the mesistele and dististele have synarthrial articulations with a central ligamentary fossa that has a figure-8 shape. The fulcral ridges change orientation from one joint to the next, giving the columnals a twisted appearance ( Fig. 2E–F ). Most rhizocrinids are fixed by rhizoids developed from the distal part of the stalk (dististele). In the fauna described here, the columnal characters do not allow a clear distinction between the different genera. The external morphology of juvenile aboral cups occasionally shows clear, discriminating characters, which tend to disappear later during growth by morphological convergence (homoplasy; for example, see Fig. 14A–I ). The abundance of material from some outcrops has allowed the recognition of juveniles and the reconstitution of ontogenic trajectories that have proved instrumental in clarifying the taxonomy (see Fig. 9 , for example). Stratigraphical distribution. Campanian-Recent.