The Erymnochelys group of turtles (Pleurodira, Podocnemididae) in the Eocene of Europe: New taxa and paleobiogeographical implications

Abstract

The Erymnochelys group is a lineage of Erymnochelyinae, pleurodiran turtles that originated in Africa, with a fossil record extending from the Late Cretaceous. It is currently represented by a single species, the Malagasy Erymnochelys madagascariensis. Information on most of its fossil representatives is sparse. In fact, the oldest unambiguous generic determinations heretofore established within the group are those of Turkanemys and Kenyemys, both from the latest Miocene-Pliocene of Kenya. The description and illustration of the French middle Eocene species 'aff. Erymnochelys' eremberti is completed here, and a diagnosis for this species is proposed for the first time. It is attributed to a new genus, Eocenochelus, the first genus of the Erymnochelys group defined outside of Africa. Eocenochelus is also recognized in the European lower and upper Eocene record by two new species, Eocenochelus lacombianus and Eocenochelus farresi, respectively. Therefore, Eocenochelus is a taxon with a wide distribution in Europe during the Eocene and is relatively diverse. This is also the case with the continental Neochelys, the only other podocnemidid genus so far recognized in the European Paleogene record. Exclusively identified in coastal deposits, Eocenochelus is the only known form of the Erymnochelys group found in marginal marine sediments. Its anatomical adaptations probably facilitated the spread from Africa to Europe.

The turtles from the upper Eocene, Osona County (Ebro Basin, Catalonia, Spain): new material and its faunistic and environmental context

“…The Spanish presence of Cordichelys is also consistent with the putative origin of Eocenochelus in northern Africa. Similarly to Eocenochelus, Cordichelys and its Shweboemys subgroup (i.e., Stereogenyina sensu stricto Gaffney et al, 2011, partim in Zouhri et al, 2017a are littoral forms which have dispersed on each northern African littoral side: eastwards up to Burma in the Indian continent and westwards up to America (Pérez-García et al, 2017b;Zouhri et al, 2017a). The presence of Cordichelys in Spain is perhaps not the only record of this form.…”

“…An indeterminate species of Eocenochelus has also been found in the lower Eocene (late Ypresian) of the English record, coming from the Brackelsham beds of Sussex (Pérez-García and Chapman, 2017). The type species of the genus is the French and Belgian middle Eocene (Lutetian) Eocenochelus eremberti (Broin, 1977) (Pérez-García et al, 2017bPérez-García and Smith, 2017). Therefore, E. eremberti is synchronous with the Taradell specimen.…”

“…1a). Apart from its presentation in several symposia (Murelaga et al, 2007;Lapparent de Broin et al, 2017;Pérez-García et al, 2017c), two detailed papers were already consecrated to some of these turtles (Lapparent de Broin et al, 2014b;Pérez-García et al, 2017b). The turtle specimens were found between 1959 and 1970 by members of the Sección de Estudios científicos 1960, del Patronato de Estudios Ausonenses, currently GeoLab-Vic, associated with the Museu Geològic del Seminari de Barcelona for the fossil preservation.…”

“…was also found. The previously described specimen of Eocenochelus (Pérez-García et al, 2017b) is the youngest turtle in the series. Is comes from the overlaying Sant Martí Xic Formation that was deposited during the latest Eocene (i.e., latest Priabonian) at the beginning of the first normal polarity of chron C16 (Fig.…”

Fish‐bearing deposits from the Upper Eocene Terminal Complex of the Plana de Vic (Catalonia, NE Spain): Sedimentary context and taphonomy

“…The fossiliferous richness of the Eocene Plana de Vic is widely known. Several papers have been published to describe its fossil plant, invertebrate, and vertebrate records (e.g., Barnolas et al, ; de Lapparent de Broin, Murelaga, Farrés, & Altimiras, ; Farrés & Altimiras, ; Farrés & Staid‐Staadt, , , ; Farrés, Vicente, & Altimiras, ; Pérez‐García, de Broin, & Murelaga, ; Reguant et al, ; Serra‐Kiel et al, ). As far as fossil fishes are concerned, Farrés () described the sawfish Mesopristis osonensis , subsequently, Farrés and Altimiras () described the swordfish Cylindracanthus rectus (Agassiz, ), and finally, Farrés and Fierstine () documented the presence of the sawfish Propristis schweinfurthi Dames, .…”