Argentinean dinosaurs and Carmen Funes museum: a ?brainy? point of view

PAULINA CARABAJAL, A.

Hwaseong

Simposio; Hwaseong International Dinosaurs Expedition Symposium; 2013

Hwaseong City, KIGAM

Argentina has one of the most complete records of Mesozoic dinosaurs. Nowadays, it is about 60-70 valid species (Novas, 2009) and that represents around the 10% of the species of the world.  The ?Carmen Funes? Museum is located in North Patagonia, on top of Neuquén Basin outcrops of Upper Cretaceous age (Figure 1). The Institution is almost 30 years old and became relevant in paleontology after the recovery by Dr. José Bonaparte, in 1989, of the bones of one of the largest dinosaurs ever found: Argentinosaurus huinculensis. The museum entry is free for locals and the ?dinosaur idea? has deep roots within the community. The building and its exhibits were renewed in 2003 to host a natural size reconstruction of Argentinosaurus, together with the carcharodontosaurid Giganotosaurus, the abelisaurid Aucasaurus, the dromaeosaurids Unenlagia and Patagonykus, and the ornithischians Anabisetia and Gasparinisaura. The collections host also the type specimens of several dinosaurs including the theropods Megaraptor and Mapusaurus and the sauropod Agustinia; sauropod eggs with embryonic bones and skin from the Aucamahuevo nesting site are also hosted in the collection. The only paleoneurological studies on Argentinean dinosaurs have been made since 2002 by the author at this museum. To obtain a cranial endocast (latex or digital), a preserved braincase is needed, but this is complex skull structure often not preserved in dinosaur skeletons (Figures 2,3). The sample of Argentinean dinosaurs with braincase is not large but informative including both, sauropods and theropods from Jurassic (the least) and cretaceous ages, most of them from Patagonia:  Mapusaurus is the largest carcharodontosaurid. Although its braincase is unknown, its close relative Giganotosaurus has a brain that is sigmoidal in shape, with large and long olfactory tract and bulbs (Paulina Carabajal and Canale, 2009). The basal theropod MCF-PVPH 411 (Coria and Currie, 2002) has one of the most complete braincases. Its braincase and brain morphology suggests a close relationship with the megalosaurids (Paulina Carabajal, 2009); however, since braincase characters are not usually used in diagnosis or phylogenies, the identity of this taxon remains uncertain. Abelisaurids with preserved braincase are Abelisaurus, Carnotarus, Aucasaurus, Skorpiovenator, Ekrixinatosaurus and Ilokelesia, although only the braincases of the first three taxa have been studied (Paulina Carabajal, 2011a,b). The most striking character in the brain of Aucasaurus is the presence of a larger floccular process than the one described for the abelisaurid from Madagascar Majungasaurus, suggesting a grater complexity of head movements for the Argentinean taxon (Paulina Carabajal and Succar, under review). Within sauropods, the best preserved titanosaurid braincases correspond to Bonatitan, Antarctosaurus (Paulina Carabajal, 2012) and two unnamed specimens (e.g. Paulina Carabajal and Salgado, 2007). This group is characterized by short and wide endocasts with low dorsal expansion, small olfactory bulbs and large pituitary (Paulina Carabajal, 2012). Whereas, the dicraosaurid brain, represented by Amargasaurus (Paulina Carabajal, 2011), and an isolated natural cast (Paulina Carabajal et al., 2012) has well developed dorsal expansions and the inner ear has larger semicircular canals than the ones of titanosaurids. New information on the brain and inner of Amargasaurus, together with the morphology of the first vertebrae, permitted interpret the neck and head position of the taxon, supporting particular feeding adaptations for the group (Paulina Carabajal et al., in press). Recently found Jurassic specimens made by the Egidio Feruglio museum staff such as prosauropods, the theropod Eoabelisaurus and an unnamed sauropod are being CT scanned, and the new information (Pol and Paulina Carabajal, in prep) will shed some light on the evolutionary pattern of saurischian brain and braincase characters trough the mesozoic.