El primer registro de sauropterigio procedente de Almería en las X Jornadas Internacionales de Salas de los Infantes

Miembros del Grupo de Biología Evolutiva de la UNED han presentado durante las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno el trabajo titulado “Preliminary systematic discussion of the first remain of Sauropterygia from Almería (southeastern Spain)”. En esta comunicación, se han presentado resultados preliminares anatómicos y sistemáticos sobre los primeros restos del grupo de reptiles marinos Sauropterygia procedentes del Triásico de Almería. A continuación, os dejamos el resumen perteneciente a este trabajo:

Sauropterygia was a successful group of aquatic reptiles with a fossil record spanning from the Olenekian (i.e., Lower Triassic) to the Maastrichtian (i.e., uppermost Cretaceous). Triassic sauropterygians can be divided into two main groups: Placodontia (i.e., durophagous forms) and Eosauropterygia, which included the most derived forms. Eosauropterygia groups the pachypleurosaurs (i.e., Pachypleurosauria); the nothosauroids (i.e., Nothosauroidea), which includes nothosaurs (i.e., Nothosauria) and simosaurs (i.e., Simosauridae); and the pistosauroids (i.e., Pistosauroidea), which includes ‘pistosaurs’ (i.e., non-plesiosaur pistosauroids) and plesiosaurs (i.e., Plesiosauria). With regards to the Spanish fossil record, all the main sauropterygian clades are represented, ranging from the Anisian (i.e., Middle Triassic) to the Maastrichtian (i.e., uppermost Cretaceous). The Spanish Triassic sauropterygian record is mostly represented by fragmentary and/or isolated remains being only diagnostic at supraspecific or suprageneric level. These remains come from Middle (i.e., Anisian and Ladinian) to Upper Triassic (i.e., probably Rhaetian) outcrops of several localities. Nonetheless, several Spanish Triassic sauropterygian species have been identified, some of them being common faunal components of other European Triassic localities (i.e., Lariosaurus balsami, Nothosaurus cf. giganteus, Nothosaurus cf. mirabilis); whereas others have been recognized as endemic Spanish forms (i.e., Parahenodus atancensis, Paludidraco multidentatus, Hispaniasaurus cranioelongatus). In this context, most of the Spanish Triassic sauropterygian remains come from the central and northeastern areas of this country, where they are represented by placodonts, pachypleurosaurs, nothosaurs, simosaurs, and pistosauroids. Conversely, sauropterygians remains in southern Spain are less abundant, having being recorded mostly from southeastern (i.e., Murcia, Jaén, Granada), but also from southwestern Spain (i.e., Huelva). Sauropterygians in southern Spain are represented by nothosaurs (i.e., Nothosaurus cf. mirabilis, Nothosaurus sp., Nothosauria indet.), pachypleurosaurs (i.e., Pachypleurosauria indet.), placodonts (i.e., Placodontia indet., Cyamodontoidea indet., Placochelyidae indet.), a probable ‘pistosaur’, a probable simosaur, and a probable nothosaur or placodont (i.e., cf. Nothosaurus/cf. Cyamodontoidea). We report here the first sauropterygian occurrence from the Triassic of Almería Province (southeastern Spain). It corresponds to an almost complete neural arch found in Sierra de Gádor in the Betic Cordillera. It is attributable to Eosauropterygia based on the presence of accessory intervertebral articulations (i.e., zygosphene-zygantrum complex) and the expanded neural arch pedicels with butterfly-shaped articulation areas for the centrum. The medium-sized neural arch displays a relative tall neural spine and short transverse processes, indicating potential nothosauroid affinities. We provide here a detailed anatomical description and the systematic study of the unpublished neural arch from Almería, in addition to a comparative analysis with the vertebrae of Eosauropterygia.