A new macronarian sauropod from the Upper Jurassic of Portugal

ABSTRACT

The Upper Jurassic of Portugal is relatively rich in sauropod remains. We describe a new sauropod specimen, which includes a partial tail, pectoral and pelvic girdle elements, and hind limb bones, from Praia de Valmitão (Praia da Amoreira-Porto Novo Formation, upper Kimmeridgian–lowermost Tithonian). This specimen constitutes the holotype of Oceanotitan dantasi, gen. et sp. nov., which shows a unique combination of characters, including the presence of anterior caudal vertebrae with a medial accessory articulation on the prezygapophysis; a circular, rough tuberosity on the medial surface of the scapula; an elliptical concavity on the ventral face of the scapula; an ischium that is shorter than the pubis; and a robust fourth trochanter located at the midline of the posterior face of the femur. Multiple phylogenetic analyses recover Oceanotitan dantasi within Titanosauriformes, with one resolving it at the base of Somphospondyli. This taxon shares several apomorphies with some Cretaceous somphospondylans and turiasaurs, such as the transverse furrow on the chevron articulations (shared with Tangvayosaurus and Phuwiangosaurus) and the ischium being shorter than the pubis (shared with Mierasaurus and somphospondylans). Oceanotitan might represent the oldest known somphospondylan, and its establishment increases the known diversity of the Late Jurassic–earliest Early Cretaceous sauropod fauna in the Iberian Peninsula, which also consists of turiasaurs, diplodocids and macronarians (non-camarasaurid, non-titanosauriform macronarians; camarasaurids; and brachiosaurids). This high diversity in sauropods suggests that this region might have played an important role during the Late Jurassic in the dispersal and diversification of several sauropod lineages between North America, Africa, and Europe, especially macronarians.

ACKNOWLEDGMENTS

This work was funded by ‘Fundação para a Ciência e Tecnologia’ (Portugal) under grant SFRH/BD/68450/2010 Ph.D. scholarship (P.M.) and Haaga Family Postdoctoral Fellow (P.M.), and Grupo de Investigación de Referencia E04_17R FOCONTUR cofinanciado por el Departamento de Innovación, Investigación y Universidad (Gobierno de Aragón) y fondos FEDER Aragón 2014-2020 “Construyendo Europa desde Aragón”, and a Synthesys Project (http://synthesys3.myspecies.info), which is financed by the European Community Research Infrastructure Action under the FP7 (FR-TAF-5072 [P.M.] and DE-TAF-6138 [P.M.]). We would like to thank the following persons for allowing us to access specimens in their care: M. Ramalho and R. Silva (MG, LNEG, Portugal), D. Brinkman and M. Fox (YPM), A. Henrici and M. Lamanna (CM), L. Chiappe and M. Walsh (NHMLAC, USA), R. Allain (MNHN, France), S. Chapman (NHMUK, U.K.), D. Schwarz (HNM, Germany), E. Howlett (OUMNH, U.K.), R. Castaninha and C. Tomás (ML, Portugal), the Herrero family (MPG, Spain), L. Póvoas, V.F. dos Santos and B. Ribeiro (MNHNC, Portugal), M. Cachão and C. M. da Silva (GeoFCUL, Portugal), M. F. C. Pereira (MDT, IST, Portugal), M. Sander (UB, Germany), N. Knötschke (DFMMh, Germany), R. Kosma (NMB, Germany), and L. Alcalá (FCPT-Dinópolis, Spain). The preparation of this specimen was mainly conducted in the Fine Art Faculty of the UCM by a team led by F. Marcos. We are also grateful to B. C. Silva, P. Dantas, G. Ramalheiro, C. Esteves, J. Reis, A. Mano, and J. J. dos Santos (SHN, Torres Vedras, Portugal); F. Escaso, I. Narváez, A. Pérez-García, C. de Miguel Chaves, A. Páramo, A. Serrano, and F. Gascó (Grupo de Biología Evolutiva, UNED, Spain); E. Malafaia, S. Pereira, and N. Pimentel (IDL, UL, Portugal); J. L. Sanz and E. Cuesta (UAM, Spain); and A. Cobos (FCPT-Dinópolis, Spain) for their support and comments. Comments made by S. F. Poropat, J. Whitlock, and an anonymous reviewer and the editor M. D’Emic helped improve an early version of this paper. The study was supported by a protocol between CMTV and SHN. The Willi Hennig Society sponsors TNT cladistics software. The generic name proposed for this new taxon, Oceanotitan, is also an homage to the song ‘Oceania,’ by Icelandic singer Björk from her 2004 album Medúlla, which inspired one of the authors (P.M.).

ORCID

Pedro Mocho http://orcid.org/0000-0002-3348-5572

Rafael Royo-Torres http://orcid.org/0000-0001-5116-3000

Francisco Ortega http://orcid.org/0000-0002-7431-354X