El saurópodo camarasauromorfo <i>Lourinhasaurus</i> en las VI Jornadas de Salas de los Infantes

Como comentábamos en posts anteriores, los saurópodos han sido protagonistas en las VI Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno de Salas de los Infantes (Burgos). Así pues, continuando con la Sauropod Party, investigadores del Grupo de Biología Evolutiva de la UNED han presentado una comunicación sobre Lourinhasaurus, en la cual llevan a cabo una puesta al día de este taxón del Jurásico Superior portugués. Este trabajo ha contado con la contribución de la Universidad Autónoma de Madrid, la Fundación Conjunto Paleontológico Teruel-Dinópolis, el Grupo de Biología Evolutiva de la UNED y la Sociedade de História Natural (Torres Vedras, Portugal).

El abstract es el siguiente:

Lapparent & Zbyszewski (1957) established a new species of Apatasaurus, A. alenquerensis, based on Portuguese Upper Jurassic material, including a relatively complete specimen of Moinho do Carmo (Alenquer). Dantas et al. (1998) erected a new genus for this material, Lourinhasaurus alenquerensis, which also included a new specimen from Porto Dinheiro (Lourinhã). However, the Porto Dinheiro specimen was posteriorly considered as the holotype of a new diplodocid named Dinheirosaurus lourinhanensis (Bonaparte & Mateus, 1999). The Moinho do Carmo specimen was firstly related with the genus Apatosaurus (Lapparent & Zbyszewski, 1957), but several authors noted the similarities between this specimen and Camarasaurus (e.g. McIntosh, 1990; McIntosh et al., 1996).

Moinho do Carmo specimen is composed by several axial and appendicular elements, being the most complete sauropod individual up to now recovered from the Portuguese Upper Jurassic. This material, including several unpublished elements from the holotype specimen, is currently under revision. The reassessment of all Lourinhasaurus alenquerensis holotype material (Mocho, 2012; Mocho et al., in review) results in a new and more complete diagnosis and codifi cations for morphological data matrices.

The cladistic analyses suggest Lourinhasaurus is a camarasauromorph macronarian supported by the presence of: i) acute posterior margin on anterior dorsal vertebrae pleurocoels, ii) opisthocoelous condition up to the first sacral vertebrae, and iii) “plank-like” anterior dorsal ribs. Lourinhasaurus alenquerensis is an exclusive taxon of Portuguese Upper Jurassic. It is close related with the Upper Jurassic sauropods Camarasaurus and Tehuelchesaurus, but a detailed comparison between those taxa supports its validity.

The study of the Upper Jurassic Portugue se sauropod fauna allows identifying the presence of several exclusive sauropods that belong to basal macronarians (Yagüe et al., 2006, this work), diplodocids (Bonaparte & Mateus, 1999; Mannion et al., 2012), turiasaurs (Mateus, 2009; Royo-Torres et al., 2009; Ortega et al., 2010; Mocho et al., 2012) or, putative brachiosaurus (Lapparent & Zbyszewski, 1957; Mannion et al., 2013). The presence of exclusive sauropod taxa does not support the hypotheses of shared Upper Jurassic peri-North Atlantic faunas (e.g. Escaso et al., 2007), although, the species represented in the Portuguese Upper Jurassic belong to the same suprageneric groups quoted at the synchronic sites at the Tendaguru Beds (Tanzania) and Morrison Formation (USA).