The first gladius-bearing coleoid cephalopods from the lower Toarcian “Schistes Cartons” Formation of the Causses Basin (southeastern France)

• Published in: PeerJ
• Main Authors: Jattiot, Romain, Coquel-Poussy, Nathalie, Kruta, Isabelle, Rouget, Isabelle, Rowe, Alison, J, Moreau, Jean-David
• Other Authors: Centre de Recherche en Paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Paleontology Taxonomy Coleoids Lower Toarcian Causses Basin Paleobiogeography Schistes Cartons; Paleontology; Taxonomy Coleoids; Lower Toarcian; Causses Basin; Paleobiogeography; Schistes Cartons; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; Arctic; Canada
• Online Access: https://hal.sorbonne-universite.fr/hal-04490124; https://hal.sorbonne-universite.fr/hal-04490124/document; https://hal.sorbonne-universite.fr/hal-04490124/file/Jattiot%20et%20al.%202024.%20Coleoids%20Causses%20Basin.pdf; https://doi.org/10.7717/peerj.16894

International audience The fossil record of gladius-bearing coleoids is scarce and based only on a few localities with geological horizons particularly favourable to their preservation (the so-called Konservat-Lagerstätten), which naturally leads to strongly limited data on geographical distributions. This emphasizes the importance of every new locality providing gladius-bearing coleoids. Here, we assess for the first time the gladius-bearing coleoid taxonomic diversity within the lower Toarcian “Schistes Cartons” of the Causses Basin (southeastern France). The material includes two fragmentary gladii, identified as Paraplesioteuthis sagittata and ? Loligosepi a sp. indet. Just with these two specimens, two (Prototeuthina and Loligosepiina) of the three (Prototeuthina, Loligosepiina and Teudopseina) suborders of Mesozoic gladius-bearing coleoids are represented. Thus, our results hint at a rich early Toarcian gladius-bearing coleoid diversity in the Causses Basin and point out the need for further field investigations in the lower Toarcian “Schistes Cartons” in this area. This new record of Paraplesioteuthis sagittata is only the second one in Europe and the third in the world (western Canada, Germany and now France). Based on these occurrences, we tentatively suggest that P . sagittata originated in the Mediterranean domain and moved to the Arctic realm through the Viking Corridor to eventually move even farther to North America.