Malarguesaurus florenciae gen. et sp. nov., a new titanosauriform (Dinosauria, Sauropoda) from the Late Cretaceous of Mendoza Province, Argentina

BERNARDO GONZÁLEZ RIGA; ELENA PREVITERA; PIRRONE CECILIA

CRETACEOUS RESEARCH (PRINT)

Año: 2008

0195-6671

Abstract Malarguesaurus florenciae gen. et sp. nov. is a new and robust somphospondylian   titanosauriform (Dinosauria, Sauropoda) from the Neuquén basin, Mendoza Province, Argentina. The specimen comes from Upper Cretaceous strata assigned to the Portezuelo Formation (late Turonian-early Coniacian). It includes proximal, middle and distal caudal vertebrae, chevrons, dorsal ribs, and appendicular bones. Malarguesaurus is characterized by the following association of characters: (1) proximal caudal neural spines vertically directed, with a concave caudal border, and a caudodorsal corner forming a right angle; (2) procoelous-opisthoplatyan proximal and middle caudal vertebrae associated with procoelous distal caudal centra; and (3) distal caudal neural spines having a concave and depressed dorsal border. A preliminar cladistic analysis placed (Ligabuesaurus + (Malarguesaurus + Phuwiangosaurus)) as a sister taxon of Titanosauria. Unique among the titanosauriforms, Malarguesaurus has procoelous distal caudal centra associated with procoelous-opisthoplatyan proximal caudals. This discovery is a new evidence of the morphologic diversity of the South American sauropods.   Keywords. Sauropoda; Mendoza; Argentina; Neuquén basin; Late Cretaceous