[D] Panamericansaurus schroederi [sG] [T]
Calvo & Porfiri 2010
Cretaceous Late Campanian Maastrichtian
Saurischia Sauropodomorpha Sauropoda Titanosauria
Allen Formation, Neuquén, near San Patricio, Patagonia, Argentina
A new sauropod [Titanosauridae], Panamericansaurus schroederi from the Allen Formation (Campanian), Neuquén province is reported here. The holotype was found in Late Campanian outcrops of NW Patagonia, Argentina. This new taxon is deeply nested within a South American Titanosaurid, named Aeolosaurini. Within Aeolosaurins, it shares all synapomorphic characters except that the anterior margin in anterior and middle caudals is not directed anterodorsally; this morphology is also present in A. colhuehuapensis. P. schroederi is unique in presenting on mid-posterior caudal vertebrae, prezigapophysis directed anterodorsaly with the length equal to or shortended than the length of ventral centrum, postzigapophysis are placed in the middle of the ventral centrum; the spinoprezigapophyseal lamina expanded dorsoventrally in middle caudals and the robust index of humerus is less than 0,40 different to other Aeolosaurins.
MUCPv-417, discovered in 2003 near San Patricio del Chañar, in Neuquén consists out of five tail vertebrae, a sacral vertebra, a left humerus, haemal arches and rib fragments. The humerus is 123 centimetres long. The total length of the holotype individual was estimated at eleven metres.
The generic name refers to the Pan American Energy company which financially supported the paleontological investigations. The specific name honours the Schroeder family on whose land the remains were found
Panamericansaurus is very similar to the closely related Aeolosaurus, differing only in details of the vertebrae. The describers placed Panamericansaurus in a clade within the Titanosauridae], the Aeolosaurini, of which also Aeolosaurus and Gondwanatitan are members