Vegasaurus molyi, gen. et sp. nov. (Plesiosauria, Elasmosauridae), from the Cape Lamb Member (lower maastrichtian) of the Snow Hill Island Formation, Vega Island, Antarctica, and remarks on Wedellian Elasmosauridae

• Published in: Journal of Vertebrate Paleontology
• Main Authors: O'gorman, Jose Patricio, Salgado, Leonardo, Olivero, Eduardo Bernardo, Marenssi, Sergio Alfredo
• Format: Article in Journal/Newspaper
• Language: English
• Published: Society of Vertebrate Paleontology
• Subjects: ELASMOSAURIDAE; VEGASAURUS MOLYI NOV. GEN. ET SP; ARISTONECTINAE; SNOW HILL ISLAND FORMATION; ANTARCTICA; https://purl.org/becyt/ford/1.5; https://purl.org/becyt/ford/1; Antarctic; Austral; Argentina; Vega Island; Hill Island; Snow Hill Island; Cape Lamb; Olivero; Ross Archipelago; Snow Hill; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/11336/53416

A new elasmosaurid, Vegasaurus molyi, gen. et sp. nov., from Vega Island, James Ross Archipelago, Antarctica, is described. The holotype and only specimen of this species (MLP 93-I-5-1) was collected from the lower Maastrichtian Cape Lamb Member of the Snow Hill Island Formation. Vegasaurus molyi is the only Antarctic elasmosaurid and one of only a few Late Cretaceous elasmosaurids from the Southern Hemisphere whose postcranial anatomy is well known. Vegasaurus molyi is distinguished from other elasmosaurids by the following combination of characters: cervical region with 54 vertebrae with elongated centra, dumbbell-shaped articular faces and lateral ridge present in the anterior and middle parts of the neck but absent in the posterior-most cervical vertebrae; scapula with ventral ramus bearing a strong ridge in the anteromedial corner of its dorsal surface; ilium shaft with expanded distal end, divided into two parts forming an angle of 140°opening anteriorly; and humerus with anterior knee and prominent posterior projection with accessory posterior articular facet. Preliminary phylogenetic analysis places V. molyi within a clade that includes the Late Cretaceous Wedellian aristonectine elasmosaurids, Aristonectes and Kaiwhekea. This indicates a close relationship between Aristonectinae and non-Aristonectinae Late Cretaceous Weddellian elasmosaurids and suggests a Weddellian origin for the Aristonectinae. Fil: O'gorman, Jose Patricio. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Salgado, Leonardo. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Marenssi, Sergio ...