Topic
Polysternon
About: Polysternon is a research topic. Over the lifetime, 9 publications have been published within this topic receiving 274 citations.
Papers
TL;DR: A fossil turtle from early Late Cretaceous deposits exposed at MacFarlane Mine in Cedar Canyon, southwestern Utah, USA is described and inferred with confidence to have originated from a brackish water facies within the late Cenomanian Culver Coal Zone of the Naturita Formation.
Abstract: Background. Bothremydidae is a clade of extinct pleurodiran turtles known from the Cretaceous to Paleogene of Africa, Europe, India, Madagascar, and North and South America. The group is most diverse during the Late Cretaceous to Paleogene of Africa. Little is known, however, about the early evolution of the group. Methods. We here figure and describe a fossil turtle from early Late Cretaceous deposits exposed at MacFarlane Mine in Cedar Canyon, southwestern Utah, USA. The sediments associated with the new turtle are utilized to infer its stratigraphic provenience and the depositional settings in which it was deposited. The fossil is compared to previously described fossil pleurodires, integrated into a modified phylogenetic analysis of pelomedusoid turtles, and the biogeography of bothremydid turtles is reassessed. In light of the novel phylogenetic hypotheses, six previously established taxon names are converted to phylogenetically defined clade names to aid communication. Results. The new fossil turtle can be inferred with confidence to have originated from a brackish water facies within the late Cenomanian Culver Coal Zone of the Naturita Formation. The fossil can be distinguished from all other previously described pleurodires and is therefore designated as a new taxon, Paiutemys tibert gen. et. sp. nov. Phylogenetic analysis places the new taxon as sister to the European Polysternon provinciale, Foxemys trabanti and Foxemys mechinorum at the base of Bothremydinae. Biogeographic analysis suggests that bothremydids originated as continental turtles in Gondwana, but that bothremydines adapted to near-shore marine conditions and therefore should be seen as having a circum-Atlantic distribution.
29 citations
TL;DR: A new species of Polysternon isonae has been recently discovered in the new locality of Barranc de Torrebilles (late Maastrichtian, southern Pyrenees) as mentioned in this paper.
21 citations
TL;DR: In this paper, a carapace of Elochelys convenarum has been found in the Campanian of Fuveau, Provence, which is the only known species of this genus.
Abstract: EXPANSION OF THE GEOGRAPHICAL AND TEMPORAL RANGE OF ELOCHELYS CONVENARUN (CHELONII BOTHREMYDIDAE) FROM DE UPPER CRETACEOUS OF THE IBERIAN PENINSULA. The Campanian and Maastrichtian chelonian fauna of Western Europe was mainly composed of endemic taxa. The Bothremydidae-represented by the genera Rosasia, Foxemys, Polysternon and Elochelys-are very abundant in this record. Elochelys is known through relatively scarce material con- sisting only of isolated plates and carapaces, which are presently assigned to two species, i.e., Elochelys perfecta and Elochelys convenarum. In France, two specimens from the Campanian of Fuveau, Provence, have been assigned to the species Elochelys perfecta; one carapace is now taken to be the holotype of the species, while the anterior half of anot- her carapace was described as the paratype. The holotype of Elochelys convenarum consists of a carapace from the up- per Maastrichtian at Cassagnau-2 (Haute-Garonne), and specimens from the upper Campanian-lower Maastrichtian at Fox Amphoux, Provence, have been tentatively assigned to this genus. In Spain, the only reference to this genus is ?Elochelys sp. from the upper Campanian fossil site of Lano, in Trevino County, Burgos. Abundant specimens of pleu- rodiran turtles have been recognized at the new Upper Cretaceous fossil locality of Lo Hueco (Fuentes, Cuenca, Spain). Herein, we refer to Elochelys convenarum a carapace from this site. This carapace is the most complete speci- men referred to Elochelys and constitutes the first robust evidence of the presence of this genus in the Iberian Peninsula, expanding the chronostratigraphic distribution of the species to the late Campanian-early Maastrichtian. Resumen. Durante el Campaniano y el Maastrichtiano, la fauna de tortugas de Europa Occidental estuvo funda- mentalmente constituida por taxones endemicos. Los Bothremydidae, representados por los generos Rosasia, Foxe- mys, Polysternon y Elochelys, son muy abundantes en este registro. Elochelys se conoce a partir de material relativa- mente escaso, compuesto unicamente por caparazones y placas aisladas, que fueron asignados a dos especies, Eloche- lys perfecta y Elochelys convenarum. En el registro frances, se ha atribuido a este genero el caparazon que constituye el holotipo de Elochelys perfecta y la mitad anterior de otro, que se describe como el paratipo de la especie, del Cam- paniano de Fuveau, en Provenza. Ademas, el holotipo de Elochelys convenarum esta constituido por un caparazon del Maastrichtiano tardio de Cassagnau-2 (Alto Garona), y se ha atribuido a este genero, con algunas reservas, material fragmentario del Campaniano tardio-Maastrichtiano terminal de Fox Amphoux, en Provenza. En Espana, la unica re- ferencia al genero es ?Elochelys sp., del Campaniano terminal de Lano (Condado de Trevino, Burgos). En el yaci- miento del Cretacico Superior de Lo Hueco (Fuentes, Cuenca, Espana) se ha reconocido abundante material de tortu- gas pleurodiras. Se estudia un caparazon de este yacimiento que se atribuye a Elochelys convenarum. Este caparazon es el material mas completo atribuido a Elochelys y supone el primer registro de este genero en la Peninsula Iberica, permitiendo ampliar la distribucion cronoestratigrafica de Elochelys convenarum al Campaniano tardio-Maastrich- tiano temprano.
15 citations
1 Jan 1999
TL;DR: In this paper, a fragmentary humerus from Apellaniz is referred to the Sauropoda as Titanosauridae indet., and a shell plate of a turtle is assigned to the Bothremydidae as cf. Polysternon sp. (Pleurodira).
Abstract: Recent field work in the Upper Cretaceous continental beds of the Basco-Cantabrian Region has yielded new vertebrate fossil remains. Both dinosaur and turtle bones have been recovered from fluviatile sediments (sub-unit B3 of Baceta et alv 1999) outcropping near Apellaniz and Korres localities (Izkiz Mountains, eastern Alava). A fragmentary humerus from Apellaniz is referred to the Sauropoda as Titanosauridae indet., and a fragmentary turtle shell plate is assigned to the Bothremydidae as cf. Polysternon sp. (Pleurodira). Moreover, two vertebral centra of Ornithopoda indet., a scute fragment of Ankylosauria indet., and turtle shell plates of cf. Polysternon and an indeterminate solemydid (Cryptodira) are known in Korres. On the basis of both geological and palaeontological grounds, a late Campanian to early Maastrichtian age is likely for the Izkiz fauna
12 citations
1 Jan 1997
TL;DR: Chelonian plate remains from the uppermost Cretaceous (Maastrichtian) of the Lleida Province in Catalonia are described for the first time and both cryptodire and pleurodire turtles are represented in the assemblage.
Abstract: Chelonian plate remains from the uppermost Cretaceous (Maastrichtian) of the Lleida Province in Catalonia are described for the first time. Both cryptodire and pleurodire turtles are represented in the assemblage. An hypoplastron from Fontllonga (Ager syndine) and a peripheral plate fragment from Biscarri, near Isona (Tremp Basin) are referred to a bothremydid cf. Polysternon sp.; isolated pleural and peripheral plates from an indeterminate locality of the Tremp area are assigned to the Solemydidae as cf. Solemys sp. Both Polysternon and Solemys are fresh-water turtles and common components of the continental vertebrate fauna of the Ibero-Occitan realm at the end of the Cretaceous
8 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2016 | 1 |
| 2012 | 2 |
| 2010 | 1 |
| 2004 | 1 |
| 2001 | 1 |
| 1999 | 2 |