A new species of Lyelliceras (Ammonoidea, Lyelliceratidae) from the Albian (Lower Cretaceous) of France

Abstract

AbstractA new lyelliceratid, Lyelliceras escragnollensis sp. nov., is described from the condensed Albian of Escragnolles (Var) and La Balme de Rencurel (Isère), as well as from the upper Lower or lower Upper Albian of Maurepaire (Aube), in France. The new species is precisely dated on the basis of a previous record from the lower Middle Albian Lyelliceras lyelli Subzone of the Hoplites dentatus Zone at Courcelles (Aube). It is regarded as a short-lived descendant of Lyelliceras pseudolyelli, and is characterised as a compressed species of the genus in which the inner ventrolateral tubercles are weak and apparently absent on the early phragmocone whorls, the outer ventrolateral clavi feeble, offset to opposite across the venter, the siphonal clavi being more numerous than the outer ventrolateral.