Journal of Paleontology; May 2009; v. 83; no. 3;
p. 389-398; DOI: 10.1666/08-030.1
© 2009 Paleontological Society
Sea Stars from Middle Jurassic Lagerstätte of La Voulte-sur-Rhone (Ardèche, France)
Loic Villier1,
Sylvain Charbonnier2,3 and
Bernard Riou4
1 Laboratoire de Géologie des Systèmes et Réservoirs Carbonatés, Université de Provence, Case 67, Batiment de Sciences Naturelles, 3 Place Victor Hugo, F-13331 Marseille, France, <loic.villier{at}univ-provence.fr>
2 UMR CNRS 5125 PEPS, Université Lyon 1, Campus de la DOUA, Batiment Géode, 69622 Villeurbanne Cedex, France
3 Muséum national d'Histoire naturelle (MNHN), Département Histoire de la Terre, UMR CNRS 7207, 8 rue Buffon, CP38, 75005 Paris, France
4 Musée des Fossiles, Les Acacias, Quartier Rondette, 07250 Rompon, France
The Callovian Lagerstätte of La Voulte-sur-Rhone represents deep (bathyal) environments at the bottom of a submarine rocky slope. Three sea star body fossils partially replaced with pyrite were collected from clay beds. A small, stellate specimen is assigned to Terminaster cancriformis, a species already known from Jurassic clay deposits of Germany, Switzerland and England. The morphology of Terminaster illustrates mostly plesiomorphic features for post-Paleozoic sea stars, and the genus may be considered either as a paedomorphic Zoroasteridae or a stem group Forcipulatacea. Two specimens of a large multiarmed sea star are assigned to Decacuminaster n. gen. solaris n. sp., characterized by a lack of abactinal plates and an axial skeleton typical of the Velatida. The two genera Xandarodaster and Plesiastropecten are close to Decacuminaster and must be transferred to the Velatida. In modern oceans, the association of a multiarmed Velatida and a zoroasterid-like species would be typical of bathyal/abyssal environments, which suggests that these groups explored deep sea environments early in their history.
Copyright © 2009 by Paleontological Society