A sauropod from the Lower Jurassic La Quinta Formation (Dept. Cesar, Colombia) and the initial diversification of eusauropods at low latitudes

• DOI: 10.1080/02724634.2021.2077112
• Publication Date: 2022-08-10T13:00:36Z
• Authors: Aldo F. Rincón; Daniel A. Raad Pá...; Harold F. Jiménez...; Martín D. Ezcurra; Jeffrey A. Wilson...
• Keywords: Sauropoda; Osteology; Autapomorphy; Outcrop

The northern-most occurrence of Sauropoda in South America was collected the 1940s from Early–Middle Jurassic-aged continental sediments on western flank Serranía del Perijá Colombia. Relocation site and re-preparation specimen, a well-preserved dorsal vertebra, provide important information about initial diversification sauropods at low latitudes. specimen possesses autapomorphies unique combination character states (e.g., divided centropostzygapophyseal lamina, strongly dorsally arched postzygapophyseal facets) that diagnose it as new genus species Perijasaurus lapaz. A medium-sized early eusauropod, inhabited tropical lowland forested areas around Toarcian–Aalenian boundary. Our phylogenetic analysis recovers near base Eusauropoda, an unresolved position Cetiosaurus, Patagosaurus kin (Bagualia, Spinophorosaurus, Nebulasaurus), more deeply nested eusauropods. bolsters idea eusauropods achieved broad geographic distribution during Jurassic, before deeper fragmentation Pangea after Toarcian faunal turnover documented high southern other basally diverging display intermediate level bone weight reduction axial column represents antecedent to highly developed pneumatic system characterizing Neosauropoda.