Vampyronassa rhodanica nov. gen. nov sp., vampyromorphe (Cephalopoda, Coleoidea) du Callovien inférieur de la Voulte-sur-Rhône (Ardèche, France)
Jean-Claude Fischer, A and Bernard Riou
Annales de Paléontologie, Volume 88, Issue 1, January-March 2002, Pages 1-17
Vampyronassa rhodanica nov. gen. nov. sp., Vampyromorpha (Cephalopoda, Coleoidea) from the Lower Callovian of la Voulte-sur-Rhône (Ardèche, France). The Vampyromorpha, an order of cephalopods closely related to Octopoda, have been yet undubitably identified only in recent time, always in deep oceanic waters. Their occurrence since the Middle Jurassic is evidenced by about twenty specimens from the Lower Callovian of la Voulte-sur-Rhône (Ardèche), which exhibit vampyromorph fundamental features : eight sessile arms showing one row of suckers with bordering cirri, a web uniting the arms, a pair of brachial tentacles, well shaped lateral eyes, an internal uncalcified supporting organ (gladius), a pair of supero-posterior fins, two postero-dorsal light-organs, no ink-sac. These specimens, here assigned to the new genus and species Vampyronassa rhodanica, still differ from recent Vampyromorpha by their two first dorsal sessile arms clearly longer than the others, their more important funnel and their longer and slightly more spindle-like body. This characteristic Middle Jurassic vampyromorph leads to admit a much older origin for this cephalopod order. The probably mesopelagic mode of life of this new vampyromorph is then tentatively examined. Critical arguments about the assignment to Vampyromorpha of three large teuthid-like species from the Upper Jurassic of Germany are developed.