NEW OCTOPODS (CEPHALOPODA: COLEOIDEA) FROM THE LATE CRETACEOUS (UPPER CENOMANIAN) OF HÂKEL AND HÂDJOULA, LEBANON
Three previously unknown octopods are described from Upper Cenomanian limestones of the Hâqel and Hâdjoula localities (Lebanon). Keuppia levante gen. nov., sp. nov., Keuppia hyperbolaris gen. nov,. sp. nov. and Styletoctopus annae gen. nov, . sp. nov. are regarded as the earliest representatives of the Octopoda (= Incirrata). This assumption is mainly based on their medially isolated bipartite gladius vestige. As can be inferred from growth increments, Keuppia gen. nov. can be distinguished from the genus Palaeoctopus by blades that grow forwards along their longitudinal axis. The gladius vestige of Keuppia hyperbolaris sp. nov. differs from that of Keuppia levante sp. nov. in having a more heterogeneous course of growth lines. Based on a pair of widely separated stylets, which closely resemble the rods of modern octopods, Styletoctopus annae gen. nov., sp. nov. is assigned to the Recent family Octopodidae. Peculiar encrustations, which are situated in close association with the gladius vestiges of Keuppia levante sp. nov., Keuppia hyperbolaris sp. nov., and Styletoctopus annae sp. nov. are interpreted as basal fin cartilages. The gladius vestige morphology of Keuppia hyperbolaris sp. nov. and Keuppia levante sp. nov. opens the possibility that both the Octopda and the Cirroctopoda originated from loligosepiid vampyropods instead of teudopseid. The surprising existence of a stylet-like gladius vestige in Styletoctopus annae sp. nov. suggests that the octopod clade branched off much earlier than previously believed. Octopod apomorphies such as the development of stylets, loss of fins and cirri must have been occurred before the Cenomanian.
Document Type: Research Article
Affiliations: 1: Institut für Geologische Wissenschaften, Fachrichtung Paläontologie, Freie Universität Berlin, Malteserstr 74-100, 12249 Berlin, Germany;, Email: [email protected] 2: Museo Civico di Storia Naturale, Corso Venezia 55, 20121 Milano, Italy;, Email: [email protected] 3: Séction Paléontologie, Musée National D`Histoire Naturelle Luxembourg, 25, rue Münster, 2160 Luxembourg, Luxembourg;, Email: [email protected]
Publication date: 01 January 2009