Marty, Daniel, 1973-
In: 5th International Symposium on Lithographic Limestone and Plattenkalk : abstracts and field guides. - Porrentruy : Société jurassienne d'Emulation, 2009. - P. 94-129
Marty, Daniel, 1973-, Bocat, Loïc
In: 5th International Symposium on Lithographic Limestone and Plattenkalk : abstracts and field guides. - Porrentruy : Société jurassienne d'Emulation, 2009. - P. 17-18
Titre: New material of “Eurysternidae” (Thalassochelydia, Pan-Cryptodira) from the Kimmeridgian of the Swiss Jura Mountains Auteur:Püntener, Christian Contributeur:Anquetin, Jérémy; Billon-Bruyat, Jean-Paul Date:
- Late Jurassic
- morphology Description:
The region of Porrentruy (Swiss Jura Mountains) is known for its rich and diverse assemblage of Late Jurassic coastal marine turtles (Thalassochelydia). Dominated by the “Plesiochelyidae”, this assemblage also includes representatives of the two other thalassochelydian groups, the “Thalassemydidae” and “Eurysternidae.” In this study, we present new shell-based material from Porrentruy referable to eurysternids. One specimen represents a juvenile individual or a relatively small taxon, and is notably characterized by a well fenestrated plastron exhibiting a wider than long central plastral fontanelle. Two other specimens are much larger and possibly represent the largest eurysternids known to date. The fourth specimen is characterized by a unique plastral morphology otherwise only known in very small juveniles. This is the first time this unique plastral morphology is known to persist in an adult or subadult. The new material described herein represents at least three distinct taxa, all of them probably new. However, we refrain from naming new species based on this incomplete material in order to avoid adding confusion to an already complex taxonomical situation. This study provides new insights into the great diversity of eurysternids during the Late Jurassic.
Publication en relation:
Palaeovertebrata. - 2020/43/1/e2
Document hôte:Palaeovertebrata Identifiant:
Titre: The comparative osteology of Plesiochelys bigleri n. sp., a new coastal marine turtle from the Late Jurassic of Porrentruy (Switzerland) Auteur:Püntener, Christian Contributeur:Anquetin, Jérémy; Billon-Bruyat, Jean-Paul Date:
- Taxonomy Description:
During the Late Jurassic, several groups of eucryptodiran turtles inhabited the shallow epicontinental seas of Western Europe. Plesiochelyidae are an important part of this first radiation of crown-group turtles into coastal marine ecosystems. Fossils of Plesiochelyidae occur in many European localities, and are especially abundant in the Kimmeridgian layers of the Swiss Jura Mountains (Solothurn and Porrentruy). In the mid-19th century, the quarries of Solothurn (NW Switzerland) already provided a large amount of fossil turtles, most notably Plesiochelys etalloni, the best-known plesiochelyid species. Recent excavations in the Porrentruy area (NW Switzerland) revealed new fossils of Plesiochelys, including numerous well-preserved shells with associated cranial and postcranial material.Out of 80 shells referred to Plesiochelys, 41 are assigned to a new species, Plesiochelys bigleri n. sp., including a skull–shell association. We furthermore refer 15 shells to Plesiochelys etalloni, and 24 shells to Plesiochelys sp. Anatomical comparisons show that Plesiochelys bigleri can clearly be differentiated from Plesiochelys etalloni by cranial features. The shell anatomy and the appendicular skeleton of Plesiochelys bigleri and Plesiochelys etalloni are very similar. However, a statistical analysis demonstrates that the thickness of neural bones allows to separate the two species based on incomplete material. This study furthermore illustrates the extent of intraspecific variation in the shell anatomy of Plesiochelys bigleri and Plesiochelys etalloni.
Publication en relation:
PeerJ. - 2017/5//e3482
Document hôte:PeerJ Identifiant:
Titre: Taxonomy and phylogeny of the turtle Tropidemys langii Rütimeyer, 1873, based on new specimens from the Kimmeridgian of the Swiss Jura Mountains Auteur:Püntener, Christian Contributeur:Billon-Bruyat, Jean-Paul; Bocat, Loïc; Berger, Jean-Pierre; Joyce, Walter G Date:
The fossil turtle Tropidemys langii is a representative of Plesiochelyidae, a traditionally recognized group of Late Jurassic turtles diagnosed by the presence of three cervical scutes and adapted to life in the sea. Tropidemys langii was previously only known from fossilized carapaces and, possibly, plastra from Europe, most notably the famous ‘Solothurn Turtle Limestone’ of Switzerland. Due to the sparse fossil record of Tropidemys langii, several questions concerning its taxonomy and phylogeny have remained unanswered. Here, new material of Tropidemys langii is reported from the Kimmeridgian of Porrentruy, Canton Jura, Switzerland. In addition to three well-preserved carapaces, associated plastra and limb bones (humerus and femur) are described for the first time. The type specimens of ‘Tropidemys valanginiensis’ and ‘Pelobatochelys blakii’ lack diagnostic characters, but can nevertheless be referred to Tropidemys. A potential extension of the lineage into the Early Cretaceous is uncertain, however, because the type locality of ‘Tropidemys valanginiensis’ is dubious. A cladistic analysis shows that Tropidemys langii is sister to Plesiochelys solodurensis, thereby tentatively confirming for the first time the monophyly of Plesiochelyidae using cladistic arguments.
Publication en relation:
Journal of Vertebrate Paleontology. - 2014/34/2/353–374
Document hôte:Journal of Vertebrate Paleontology Identifiant: