Describer

Filippi, Garcia & Garrido 2011

Time

Cretaceous Late Campanian

Classification

Saurischia Sauropodomorpha Sauropoda Titanosauria [Lithostrotia Upchurch, Barrett and Dodson, 2004] Nomen Nudem

Diet

Herbivore

Fossilsite

Anacleto Formation, Neuquén Group, Río Colorado Subgroup, Argentina

Info

Abstract

A new sauropod titanosaur from the Upper Cretaceous Anacleto Formation is described. Narambuenatitan palomoi gen. et sp. nov., is diagnosed by cranial and axial autapomorphies. The holotype, which represent a subadult individual, consists of the left premaxilla and maxilla, braincase, both quadrates, one cervical vertebrae, one dorsal vertebra, fragments of cervical and dorsal ribs, seventeen caudal vertebrae, caudal transverse processes, fragments of haemal arches, left sternal plate, right coracoid, left humerus, left ulnae, both pubes, iliac pedicel, proximal fragment of right ischia, and an incomplete left femur. The phylogenetic analysis indicates that Narambuenatitan is a noneutitanosaurian lithostrotian, and that it shares with Epachthosaurus a neural spine in middle caudal vertebrae which are laminar and posteriorly elongated.

Etymology

Narambuena: in reference to Puesto Narambuena, the area where the holotype of the type species was found, and titan: to correspond to a titanosaur specimen. | palomoi, in reference to Salvador Palomo, technician of the Museo Municipal “Argentino Urquiza”, Rincón de los Sauces, Neuquén, who found the specimen, and in acknowledgment of his permanent contribution to the local paleontology.

Holotype

MAU-Pv-N-425, partial skeleton consisting of the following associated elements: left premaxilla and maxilla; braincase; left and right quadrates; anterior cervical vertebra; cervical rib fragments; posterior dorsal vertebra; three dorsal ribs; eleven anterior caudal vertebrae; six middle caudal vertebrae; two caudal transverse processes; two fragments of haemal arches; left sternal plate; right coracoid; left humerus; left ulna; left and right pubes; pubic peduncle of the left ilium; proximal fragment of the right ischium; and incomplete left femur.

Horizon and age

Neuquén Group (Upper Cretaceous), Río Colorado Subgroup, Anacleto Formation (lower to middle Campanian, Dingus et al. 2000).

Diagnosis

Titanosaur characterized by the following autapomorphies: great participation of the frontal to the rostral border of the supratemporal fossa, absence of ornamentation on the supraorbital or lateral borders of the frontal, presence of a lamina joining each parietal crest with the rostral surface of the supratemporal, pleurocoel dorsal border defined by a prominent convex bony edge in posterior dorsal vertebrae, distal enlargement of the prespinal lamina in posterior dorsal vertebrae, matching with a lateral enlarged of the neural spine, kidney-shaped prezygapophysis in posterior dorsal vertebrae, presence of numerous pneumatic cavities located posterior to the centroparapophyseal lamina and centrodiapophyseal lamina in posterior dorsal vertebrae, middle-anterior caudal vertebrae with the anterodorsal border of the neural spine anteriorly inclined, middle caudal vertebra with a slender prezygapophysis and neural arch.