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RESEARCH PRODUCT

Gladius-bearing coleoids from the Upper Cretaceous Lebanese Lagerstätten: diversity, morphology, and phylogenetic implications.

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AbstractGladius-bearing coleoids are rare in the fossil record. For the Cretaceous period, these cephalopods are mainly recorded in a few Lagerstätten in Lebanon (Haqel, Hajoula, En Nammoura, and Sahel Aalma). Here, we study 16 specimens of gladius-bearing coleoids from these Upper Cretaceous Lebanese Lagerstätten to investigate their taxonomic diversity. Besides two species that were already reported (Dorateuthis syriacaandGlyphiteuthis libanotica), one new species is identified in the Cenomanian site of Hajoula:Rachiteuthis acutalin. sp., as well as another form ofGlyphiteuthisfrom En Nammoura. Several studied specimens exhibit well-preserved soft-part characters. Among them, we document for the first time two transverse rows of sessile suckers inD.syriacaand we confirm the absence of tentacles, as well as the presence of a crop in this species. This strongly supports the phylogenetic proximity ofD.syriacawith modern vampyropods rather than with modern decabrachians. In turn, the similarity in gladius morphology between this taxon and modern squids is regarded as convergent.