New fossil triakid sharks from the early Eocene of Premontre, France, and comments on fossil record of the family

• Published in: Acta Palaeontologica Polonica
• Main Authors: Adnet, Sylvain, Cappetta, Henri
• Other Authors: Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement IRD : UR226-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: Chondrichthyes; Triakidae; Galeorhinus; Gomphogaleus; Eocene; France; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE]; North Atlantic
• Online Access: https://hal.science/halsde-00454629; https://hal.science/halsde-00454629/document; https://hal.science/halsde-00454629/file/app53-433.pdf; https://doi.org/10.4202/app.2008.0306

International audience During the last two decades, an abundant selachian assemblage has been collected from the late Ypresian (NP12) fossiliferous sands of Premontre (Aisne, northern France) but has received little attention. Sharks of the family Triakidae (Carcharhiniformes) are particularly well represented and all are described and figured herein. Among them, two new species of the genus Galeorhinus are described: G. duchaussoisi sp. nov. and G. louisi sp. nov.; these are compared to the common Paleogene G. ypresiensis which is refigured. Another triakid taxon, the genus Gomphogaleus gen. nov., is described. Most of the triakids have been recorded elsewhere in the North Atlantic region, suggesting a wider distribution than expected for these small sharks during the Paleogene. The present paper updates the list of selachians from Premontre, bringing the number of taxa from 19 to 33 (including 22 sharks and 11 batoids) and improving our knowledge of the ancient North Atlantic Ypresian selachian fauna. Despite this vastly improved record, it is clear that fossil data are still very incomplete and insufficient for calibrating phylogenetic hypotheses of living forms. Review of the Premontre fauna shows that the Triakidae were much more diverse and broadly distributed than at present, suggesting that the limited distribution and low diversity of living forms is probably a recent phenomenon.