New material of the platychelyid turtle Notoemys zapatocaensis from the early cretaceous of colombia; implications for understanding pleurodira evolution
Notoemys zapatocaensis is the youngest representative of the Platychelyidae, a group of Late Jurassic-Early Cretaceous pleurodires. Here we describe two new specimens of this species represented by a partial carapace and a nearly complete articulated shell. Notoemys zapatocaensis is different from o...
- Autores:
- Tipo de recurso:
- Fecha de publicación:
- 2012
- Institución:
- Universidad del Rosario
- Repositorio:
- Repositorio EdocUR - U. Rosario
- Idioma:
- eng
- OAI Identifier:
- oai:repository.urosario.edu.co:10336/28872
- Acceso en línea:
- https://doi.org/10.1007/978-94-007-4309-0_8
https://repository.urosario.edu.co/handle/10336/28872
- Palabra clave:
- Rosablanca formation
South America
Valanginian Zapatoca
- Rights
- License
- Restringido (Acceso a grupos específicos)
| Summary: | Notoemys zapatocaensis is the youngest representative of the Platychelyidae, a group of Late Jurassic-Early Cretaceous pleurodires. Here we describe two new specimens of this species represented by a partial carapace and a nearly complete articulated shell. Notoemys zapatocaensis is different from other platychelyid turtles in having: (1) two fairly reduced lateral tuberosities on the margin of the anterior plastral lobe, (2) a shallow notch on the posterolateral margin of the epiplastra, giving a convex posterolateral edge to this bone, (3) gular scales that are rectangular in shape and much wider than long, (4) a long intergular scale that has a slight medial contact with the pectorals, resulting in a complete separation of the humeral scales, (5) a central plastral fontanelle that projects posteriorly into the xiphiplastral region, (6) a very small marginal 3, (7) a slightly shorter neural 1 than neural 2, with an exclusive lateral contact with costal 1, resulting in a complete separation of neural 2 and costal 1, (8) narrower vertebral scales, and (9) peripheral 3 lacking a posteromedial contact with costal 2. Phylogenetic analysis indicates that N. zapatocaensis is a sister taxon of N. oxfordiensis, and that Proterochersis robusta can be resolved in two different positions in the testudines tree: (1) with Odontochelys semitestacea based on the fact that both taxa share two mesoplastra meeting at midline, or (2) as the most basal pleurodire, based on a suture articulation of pelvis to shell. Anal notch shape and potentially fontanelle size are indicators of sexual dimorphism in platychelyids. |
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