title: New sea spiders from the Jurassic La Voulte-sur-Rhône Lagerstätte.
abstract: The diverse and exceptionally well-preserved pycnogonids described herein from the Middle Jurassic La Voulte Lagerstätte fill a 400 Myr gap of knowledge in the evolutionary history of this enigmatic group of marine arthropods. They reveal very close morphological and functional (locomotion, feeding) similarities with present-day pycnogonids and, by contrast, marked differences with all Palaeozoic representatives of the group. This suggests a relatively recent, possibly Mesozoic origin for at least three major extant lineages of pycnogonids (Ammotheidae, Colossendeidae, Endeidae). Combined evidence from depositional environment, faunal associates and recent analogues indicate that the La Voulte pycnogonids probably lived in the upper bathyal zone (ca 200 m). Our results point to a remarkable morphological and ecological stability of this arthropod group over at least 160 Myr and suggest that the colonization of the deep sea by pycnogonids occurred before the Jurassic.
authors: UMR 5125 PEPS, CNRS, Université Lyon 1, Campus de la Doua, Bâtiment Géode, 69622 Villeurbanne Cedex, France. sylvain.charbonnier@univ-lyon1.fr
authors: S
authors: S
authors: Charbonnier
authors: J
authors: J
authors: Vannier
authors: B
authors: B
authors: Riou
mesh_terms: D000818:Animals; D001181:Arthropods / Q000033:anatomy & histology* / Q000145:classification*; D005580:Fossils; D005602:France; D008386:Marine Biology; D010802:Phylogeny; D013997:Time Factors
references: Dev Genes Evol. 2006 Jul-Aug;216(7-8):481-91
references: 16820954
references: Arthropod Struct Dev. 2003 Dec;32(4):349-83
references: 18089018
references: Nature. 2004 Oct 21;431(7011):978-80
references: 15496921
references: Nature. 2005 Oct 20;437(7062):1144-8
references: 16237442
references: Mol Phylogenet Evol. 2003 Sep;28(3):588-600
references: 12927141
references: Nature. 2006 May 25;441(7092):506-8
references: 16724066
references: Nature. 2001 Sep 13;413(6852):157-61
references: 11557979
references: Cladistics. 2007 Jun;23(3):255-293
references: 34905863
references: Mol Phylogenet Evol. 2006 Jan;38(1):100-16
references: 16290034