The first noasaurid theropod (Dinosauria) from the Upper Jurassic of Portugal (Lourinhã Formation, Porto Dinheiro, Lourinhã)

• Autor(a) principal: Ribeiro, Cátia Fernandes
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/145229
• topic: Noasauridae; Ceratosauria; Theropoda; Dinosauria; Lourinhã Formation; Porto Dinheiro; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Dinosaurs are undoubtedly the best studied and most recognizable clade of fossil tetrapod vertebrates – and among these, none are more popular with specialists and non-specialists alike than the various forms of the predominantly carnivorous theropods. However, there is a scarcely known theropod clade, effectively with one of the poorest fossil record and fewer studies among dinosaurs: Noasauridae. Portugal has a well representative fossil record of non-avian theropods, including genera from Megalosauroidea, Allosauroidea, Coelurosauria, and Ceratosauria, most known from the Lourinhã Formation. A new theropod specimen (ML 2050) was discovered in 2013, in the Upper Jurassic, at Porto Dinheiro beach (Lourinhã, Portugal), in the Lourinhã Formation (Amoreira-Porto Novo Member, upper Kimmeridgian), currently housed at the Museum of Lourinhã. The specimen consists of semi-articulated postcranial elements, including dorsal and caudal vertebrae, dorsal ribs, gastralia, chevrons, scapulocoracoids, right humerus, pubic fragments, and hindlimb elements (portions of the right femur, tibia and fibulae, and an almost complete left foot). After description, comparisons, and phylogenetical analysis, ML 2050 was found to belong to Noasauridae, a clade within Ceratosauria (Theropoda) characterized by medium to small-bodied slender forms, that was found to occur mostly in the Gondwana from the Late Jurassic to the Late Cretaceous. This new specimen is at this point the only definitive noasaurid from Europe, and the third in the Northern Hemisphere, after Limusaurus inextricabilis and CCG 20011. The results of the phylogenetical analyses show that ML 2050 is more closely related to Elaphrosaurus bambergi than to Limusaurus inextricabilis, and is closer to these than to Noasaurus leali, placing it in the noasaurid subclade Elaphrosaurinae. Considerations are also given on the distribution of Noasauridae around the world, the possible Gondwanan origin and the possible oldest members of the clade.