Published October 15, 2021 | Version v1
Taxonomic treatment Open

Paraconocrinus rhodanicus Roux & Philippe 2021, n. sp.

  • 1. Muséum national d'Histoire naturelle, UMR 7205 ISYEB MNHN-CNRS-UPMC-EPHE, Département Systématique et Évolution, CP
  • 2. Centre " Louis Lortet de conservation et d'étude des collections (Musée des Confluences, Lyon) 13 A, rue Bancel - 69007 Lyon, France. https: // orcid. org / 0000 - 0002 - 4582 - 8990

Description

Paraconocrinus rhodanicus n. sp.

Fig. 12G–K, 13, Table 8

Type material. 26 Co not figured (MHNL 20062728) + 4 Co figured (MHNL 20062727).

Etymology. Reference to the Rhodanian basin.

Additional material. 1 AC, 1 Co from Vedène.

Diagnosis. As in description.

Type stratum. Late Burdigalian.

Type locality. Place du Palais des Papes in Avignon.

Description. 30 Co (quantitative characters given in Table 8) corresponding to a stalk length of 62.5 mm. Co from distal stalk with proximal facet having one or more projections ended by rhizoid insertion at one (Fig. 12G) or both sides (Fig. 12J–K) of fulcral ridge. Co from mesistele without rhizoid, more elongated (1<H/D<1.5) with oval (D/d <0.85) synarthries (Fig. 14I). Distally, Co with weaker H/D (tending to 0.7), narrower (D/d tending to 2.5) spindle-shaped synarthries (Figs.12G, J) with more robust rhizoid socket (Fig. 12J). Synarthrial facets of classical Conocrinus type (see Roux et al. 2019) with a deep 8-shaped ligament fossa; fulcral ridge of two segments with axis hollowed, regular crenularium reaching ~20 small Cr on each side and bordered by slightly depressed ligament areas (Fig. 12H).

Worn material from Vedène presumedly belonging to P. rhodanicus n. sp. Oblong aboral cup, preserved H 6.9 mm, D maximum 4.0 mm, stalk insertion 1.98 mm. Co with H 2.70 mm, D 2.95 mm and d 2.10 mm.

Remarks. Paraconocrinus rhodanicus n. sp. is a small species with distal Co articulated by narrow synarthries of fulcral ridge bordered by slightly depressed areas as in most species of the genus Paraconocrinus (Merle and Roux 2018; Roux et al. 2019). The Co figured from the Middle Miocene near Turin (see especially Albus 1931 and Manni 2005) differ in having a larger size and more massive shape. As previously usual, isolated Miocene rhizocrinid Co had been attributed to the most classically cited Eocene species: “ Conocrinusthorenti (d’Archiac 1846) or “ Conocrinuspyriformis (Münster in Goldfuss, 1826). “ Conocrinusseguenzai Meneghini, 1875, known only from aboral cups from the Miocene of Piedmont (Noelli 1900; Manni 2005), is the only rhizocrinid species clearly identified, but the published figures are too imprecise to attribute it to one of the genera distinguished by Roux et al. (2019). Although very worn, the aboral cup from Vednes, which may belong to P. rhodanicus n. sp., differs markedly from “ Conocrinusseguenzai.

Occurrence in southeastern France. Avignon (Place du Palais des Papes), Les Angles?, Vedène?, Late Burdigalian, Early Langhian?

Notes

Published as part of Roux, Michel & Philippe, Michel, 2021, Early Miocene stalked crinoids (Echinodermata) from the southern Rhodanian basin (southeastern France). Paleoenvironments and taxonomy, pp. 301-331 in Zootaxa 5052 (3) on page 325, DOI: 10.11646/zootaxa.5052.3.1, http://zenodo.org/record/5572077

Files

Files (3.3 kB)

Name Size Download all
md5:94d80e4ad19d379b946eecaf02425cf7
3.3 kB Download

System files (30.2 kB)

Name Size Download all
md5:f9f22b2b4cc7acab6f13932e6377036b
30.2 kB Download

Linked records

Additional details

Biodiversity

Collection code
MHNL
Event date
2727-06-20
Verbatim event date
2727-06-20/2728-06-20
Scientific name authorship
Roux & Philippe
Kingdom
Animalia
Phylum
Echinodermata
Order
Comatulida
Family
Bathycrinidae
Genus
Paraconocrinus
Species
rhodanicus
Taxon rank
species
Taxonomic status
sp. nov.
Type status
holotype
Taxonomic concept label
Paraconocrinus rhodanicus Roux & Philippe, 2021

References

  • Roux, M., Eleaume, M. & Ameziane, N. (2019) A revision of the genus Conocrinus d'Orbigny (Echinodermata, Crinoidea, Rhizocrinidae) and its place among extant and fossil crinoids with a xenomorphic stalk. Zootaxa, 4560 (1), 51 - 84. https: // doi. org / 10.11646 / zootaxa. 4560.1.3
  • Merle, D. & Roux, M. (2018) Stalked crinoids from Gan (Late Ypresian, southwestern France): exceptional stereom preservation, paleoecology and taxonomic affinities. Swiss Journal of Paleontology, 137 (2), 225 - 244. https: // doi. org / 10.1007 / s 13358 - 018 - 0162 - 0
  • Albus, L. (1931) Nuove ricerche sui crinoidi miocenici della collina di Torino. Bollettino della Societa geologica italiana, 49, 279 - 296.
  • Manni, R. (2005) The non-isocrinid crinoids of the Michelotti Collection. Bolletino della Societa paleontologica italiana, 44 (3), 211 - 218.
  • Goldfuss, G. A. (1826) Petrefacta Germaniae, divisio secunda. Radiarorum reliquiae. Vol. 1. Arnz & Co, Dusseldorf, pp. 115 - 221.
  • Noelli, A. (1900) Contribuzione allo studio dei Crinoidi terziari del Piemonte. Atti della Societa italiana di Scienze naturali e del Museo Civico di Storia naturale, Milano, 39 (1), 19 - 50.