Estudio de los primeros restos de pistosaurios de Oriente Medio 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 “On the potential presence of ‘pistosaurs’ in the Middle Triassic of the Middle East”. En esta comunicación, se han presentado resultados preliminares anatómicos y sistemáticos sobre los primeros restos de pistosaurios de Israel, un grupo de reptiles marinos estrechamente emparentados con los plesiosaurios. A continuación, os dejamos el resumen perteneciente a este trabajo:

Pistosauroids (Pistosauroidea, Eosauropterygia) are a monophyletic group of sauropterygians that include the well-known plesiosaurs (i.e., Plesiosauria) as well as other basal forms from the Triassic. This clade was the most successful among Sauropterygia considering that they were globally distributed and that their fossil record spans from the probably Lower Triassic (i.e., Olenekian) to the uppermost Cretaceous (i.e., Maastrichtian). The oldest record for Triassic pistosauroids probably occurs in the Lower Triassic, with the putative pistosauroid Corosaurus alcovensis, from the Olenekian of USA or, alternatively, with the pistosauroid Kwangsisaurus orientalis, from the Olenekian or earliest Anisian of China; whereas the youngest record is represented by the plesiosaurian Rhaeticosaurus mertensi from the Rhaetian (i.e., uppermost Triassic) of Germany. Most of these Triassic forms belong to the non-plesiosaur pistosauroids, with Bobosaurus forojuliensis from the Carnian (Upper Triassic) of Italy, having been hitherto considered as the youngest known representative. Non-plesiosaur pistosauroids are informally referred to as ‘pistosaurs’, previously considered to conform a monophyletic group (i.e., the Pistosauria) or, more recently, having been considered paraphyletic. ‘Pistosaurs’ remains have been recovered from USA, China, Europe, and North Africa. Nonetheless, the knowledge about this group is relatively limited relative to other Triassic sauropterygians due to the incompleteness of their fossil record and the lack of well-preserved specimens. The most abundant and best-preserved ‘pistosaur’ material corresponds to that of Yunguisaurus liae, from the Ladinian (Middle Triassic) of China, and Pistosaurus longaevus, from the Anisian (Middle Triassic) of Germany and Poland. In this sense, ‘pistosaurs’ have never been reported from any Middle East Triassic locality, where several other Triassic sauropterygian clades occur (i.e., Placodontia, Pachypleurosauria, Nothosauria, and Simosauridae), especially in the Middle Triassic levels of Makhtesh Ramon (Negev, south Israel). In this work, we present several unpublished vertebral remains from the Muschelkalk levels (Anisian or Ladinian) of Makhtesh Ramon. The vertebral material seems incompatible with any sauropterygian clade previously described in this region, but potentially akin to the non-plesiosaurian pistosauroids (i.e., ‘pistosaurs’). We provide here both preliminary anatomical descriptions and a systematic study of this vertebral material, in addition to an anatomical comparative study with other ‘pistosaurs’.

-----
Más información: