Asteroidea (Echinodermata) from the Oxfordian (Late Jurassic) of Savigna, Départment du Jura, France

Abstract

The asteroid fauna from the Late Oxfordian marls (bifurcatus Zone, stenocycloides Subzone) of Savigna includes 11 taxa, distributed between 8 families, of which 1 (Plumasteridae) is new. A goniasterid of distinctive morphology, Hessaster longimarginalis, is described as new, as is an asteriid, Savignasterias villieri. The material was recovered by surface picking and processing over 1,000 kg of sediment, and includes 28 partial individuals and approximately 2,000 isolated ossicles in excellent preservation, which show fine details of the stereom architecture and additionally allow ontogenetic changes to be described. Detailed comparison with extant asteroids enables diverse ossicle types to be assigned precisely to individual taxa. The phylogenetic relationships of individual fossil species with living taxa are determined using characters derived from numerous skeletal elements, and it is shown that the benthopectinid and pterasterid species present in the Savigna fauna are basal to their respective families. In comparison with other assemblages collected from Jurassic clay facies, the Savigna asteroid fauna is unusually diverse. Importantly, the fauna includes elements typical of present day deep sea environments (bathyal and abyssal), living abundantly in Oxfordian shelf seas of about 50 m depth.

Temporary expansion to shelf depths rather than an onshore-offshore trend: the shallow-water rise and demise of the modern deep-sea brittle star family Ophiacanthidae (Echinodermata: Ophiuroidea)

“…Savigna, France; sample S2a of Gale (2011), Bimammatum Zone, late Oxfordian, Late Jurassic. (2011); GZG.INV.78660 (47 dissociated LAPs) from sample S1 of Gale (2011); GZG.INV.78661 (166 dissociated LAPs) from sample S2b of Gale (2011).…”

“…(2011); GZG.INV.78660 (47 dissociated LAPs) from sample S1 of Gale (2011); GZG.INV.78661 (166 dissociated LAPs) from sample S2b of Gale (2011).…”

“…GZG.INV.78768 (29 dissociated LAPs) from sample S2b of Gale (2011), GZG.INV.78769 (6 dissociated LAPs) from sample S1 of Gale (2011), GZG.INV.78770 (8 dissociated LAPs) from sample S2a of Gale (2011), all from the Bifurcatus Zone, late Oxfordian of Savigna, France; dissociated LAP from the Bifurcatus Zone, late Oxfordian of Guldental, Switzerland, the original material of Hess (1966); 26 dissociated LAPs from the Renggeri Member, early Oxfordian of Chapois, France, the original material of Hess (1965a); 2 dissociated LAPs from the Renggeri Member of Longecombe, France, the original material of Hess (1965a).…”

“…NHMB M1124, NHMB M11225 and 3 dissociated LAPs from the late Oxfordian of Savigna, France, the type material of Hess (1966); GZG.INV.78805 (1 dissociated LAP) from sample S1 of Gale (2011), GZG.INV.78806 (2 dissociated LAPs) from sample S2a of Gale (2011) and GZG.INV.78807 (4 dissociated LAPs) from sample S2b of Gale (2011), all from the Bifurcatus Zone, late Oxfordian of Savigna, France; 2 dissociated LAPs from the Bifurcatus Zone of Guldental, Switzerland, the original material of Hess (1966).…”

Un astropectínido (Echinodermata, Asteroidea) cretácico temprano de Patagonia (Argentina): Una nueva especie y el registro más antiguo de la familia para el Hemisferio Sur.

“…An overview of the main record of astropectinid fossils is given by Jagt (2000). Most Jurassic records were reported from Europe, India and the USA (e.g., Blake, 1981Blake, , 1986Breton, 1997;Gale, 2011;Hess, 1973;Kutscher and Röper, 1999;Spencer and Wright, 1966;Srivastava et al, 2010;Villier, 2008;Villier et al, 2004).…”