Europatitan eastwoodi, a new sauropod from the lower Cretaceous of Iberia in the initial radiation of somphospondylans in Laurasia

PeerJ. 2017 Jun 27:5:e3409. doi: 10.7717/peerj.3409. eCollection 2017.

Abstract

The sauropod of El Oterillo II is a specimen that was excavated from the Castrillo de la Reina Formation (Burgos, Spain), late Barremian-early Aptian, in the 2000s but initially remained undescribed. A tooth and elements of the axial skeleton, and the scapular and pelvic girdle, represent it. It is one of the most complete titanosauriform sauropods from the Early Cretaceous of Europe and presents an opportunity to deepen our understanding of the radiation of this clade in the Early Cretaceous and study the paleobiogeographical relationships of Iberia with Gondwana and with other parts of Laurasia. The late Barremian-early Aptian is the time interval in the Cretaceous with the greatest diversity of sauropod taxa described in Iberia: two titanosauriforms, Tastavinsaurus and Europatitan; and a rebbachisaurid, Demandasaurus. The new sauropod Europatitan eastwoodi n. gen. n. sp. presents a series of autapomorphic characters in the presacral vertebrae and scapula that distinguish it from the other sauropods of the Early Cretaceous of Iberia. Our phylogenetic study locates Europatitan as the basalmost member of the Somphospondyli, clearly differentiated from other clades such as Brachiosauridae and Titanosauria, and distantly related to the contemporaneous Tastavinsaurus. Europatitan could be a representative of a Eurogondwanan fauna like Demandasaurus, the other sauropod described from the Castrillo de la Reina Formation. The presence of a sauropod fauna with marked Gondwananan affinities in the Aptian of Iberia reinforces the idea of faunal exchanges between this continental masses during the Early Cretaceous. Further specimens and more detailed analysis are needed to elucidate if this Aptian fauna is caused by the presence of previously unnoticed Aptian land bridges, or it represents a relict fauna from an earlier dispersal event.

Keywords: Dinosauria; Early Cretaceous; Europatitan eastwoodi; Fossil bones; New species; Sauropoda; Somphospondyli; Spain; Titanosauriformes.

Grants and funding

The fieldwork was financed by the “Dirección General de Patrimonio de la Junta de Castilla y León” and the “Fundación para el estudio de los dinosaurios de Castilla y León.” This paper is part of the collaboration between the “Colectivo Arqueológico y Paleontológico Salense,” the “Museo de los Dinosaurios de Salas de los Infantes,” and Zaragoza University. It is partially subsidized by the project CGL2014-53548-P of the Spanish Ministerio de Economía y Competitividad, the European Regional Development Fund, the European Social Fund, and the Government of Aragón (“Grupos Consolidados”). MMA is supported by the Fundação para a Ciência e a Tecnologia, grant number SFRH/BPD/113130/2015. There was no additional external funding received for this study The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.