A complete endocast of Giganotosaurus carolinii Coria & Ssalgado, 1995 was made in latex after removing mechanically the sediment filling of the cerebral cavity of the braincase, thereby allowing the description of the endocranial anatomy of the specimen. The endocast was compared with the other few known natural or artificial theropod endocasts, including the two species of the African allosauroid species Carcharodontosaurus saharicus and C. idiguensis. As in Carcharodontosaurus, the olfactory bulbs in Giganotosaurus are aligned with the forebrain, the midbrain is posteroventrally inclined and the hindbrain is parallel but ventral to the forebrain, showing similarly angled cephalic and pontine flexures. The cranial nerves and blood vessels have a similar disposition as in Carcharodontosaurus saharicus. However, in Giganotosaurus there is only one branch for cranial nerve XII, and cranial nerve XI has a separate internal opening from the vagus foramen (metotic foramen). In C. saharicus, there is a separate opening as well, but it is anterior in position and was probably utilized by cranial nerve IX. The length of the endocast of Giganotosaurus, including the olfactory bulbs, is approximately 19 % longer than the endocast in Carcharodontosaurus saharicus.

Paulina Carabajal, A. & Canale, J. I. ,2010: Cranial endocast of the carcharodontosaurid theropod Giganotosaurus carolinii Coria & Salgado, 1995. – N. Jb. Geol. Paläont. Abh., DOI: 10.1127/0077-7749/2010/0104; Stuttgart.

Auditorio del Museo Provincial de Ciencias Naturales
Prof. Dr. Juan A. Olsacher.
Etcheluz y Ejército Argentino. Zapala. Neuquén.


Presentación a cargo del Ggo. Alberto Garrido, director del Museo Provincial de Ciencias Naturales “Prof. Dr. Juan A. Olsacher”. Dirección Provincial de Minería. Zapala, provincia del Neuquén.

Proyección:
“El hombre detrás de los huesos” es un documental de crónica humana, que aborda la vida de José Bonaparte. Un paleontólogo ejemplar. Un hombre que fue más allá de sus propios limites, autodidacta en su formación. Perseverante, tenaz y visionario en su trabajo. Sus hallazgos son reconocidos a nivel mundial. Una vida dedicada a la búsqueda del conocimiento con anhelos y frustraciones, con dichas y desdichas, con alegrías y culpas. Una vida que hoy sigue y seguirá buscando. José Bonaparte es el hombre detrás de los huesos. Un largometraje de 52 minutos realizado por Lic. Paola Echecury.

Charlas Informativas:
Participación especial de:

Dr. Leonardo Salgado, investigador de CONICET – INIBIOMA, Director del Museo de Geología y Paleontología de la Universidad Nacional del Comahue, Neuquén. Realizó su tesis bajo la dirección del Dr. Bonaparte. Anécdotas y vivencias nos acercan a conocer más sobre la vida de este paleontólogo.

Prof. Leonardo S. Filippi. Paleontólogo. Investigador Asociado al Museo Provincial de Ciencias Naturales “Prof. Dr. Juan A. Olsacher”, Zapala, Neuquén. Nos cuenta sobre sus primeras experiencias en este fascinante mundo de la paleontología compartiendo trabajos de campo junto al Dr. Bonaparte.

Oscar A. Alcober and Ricardo N. Martínez

Herrerasauridae comprises a basal clade of dinosaurs best known from the Upper Triassic of Argentina and Brazil, which have yielded remains of Herrerasaurus ischigualastensis and Staurikosaurus pricei, respectively. Systematic opinion regarding the position of Herrerasauridae at the base of Dinosauria has varied. Here we describe a new herrerasaurid, Sanjuansaurus gordilloi gen. n., sp. n., based on a partial skeleton from Carnian-age strata of the the Upper Triassic Ischigualasto Formation of northwestern Argentina. The new taxon is diagnosed by numerous features, including long, band-shaped and posterolaterally oriented transverse process on the posterior cervical vertebrae; neural spines of the sixth to eighth dorsal vertebrae, at least, bearing acute anterior and posterior processes; scapula and coracoid with everted lateral margins of the glenoid; and short pubis (63% of the femoral length). Phylogenetic analysis placed Sanjuansaurus within a monophyletic Herrerasauridae, at the base of Th eropoda and including Herrerasaurus and Staurikosaurus. The presence of Sanjuansaurus at the base of the Ischigualasto Formation, along with other dinosaurs such as Herrerasaurus, Eoraptor, Panphagia, and Chromogisaurus suggests that saurischian dinosaurs in southwestern Pangea were already widely diversifi ed by the late Carnian rather than increasing in diversity across the Carnian-Norian boundary.

Alcober OA, Martinez RN (2010) A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina. ZooKeys 63 : 55 – 81.

Estudio preliminar anatómico de peces Chondrostei provenientes de la Formación La Cantera, Sierra del Gigante. Cretácico Inferior, San Luis

G. Castillo Elías y L. Codorniú

La Cantera es una de las unidades litoestratigráficas que componen el Grupo del Gigante, cuya asociación fósil fue asignada al Aptiano (110 Ma.). Todo el material extraído hasta la actualidad proviene del miembro basal compuesto de areniscas finas y de limolitas. En particular, los peces extraídos de esta formación lacustre pertenecen a diferentes grupos como teleósteos basales, y actinopterygios muy primitivos. Estos últimos son los peces más abundantes del yacimiento y fueron asignados mediante estudios preliminares a la superdivisión Chondrostei; clado que se originó muy probablemente durante el Triásico. Unos pocos géneros y especies se diversificaron en el Cretácico inferior, edad a la que pertenece el espécimen estudiado. MHIN-UNSL-V-562 posee un muy buen estado de preservación en forma bidimensional, presenta forma fusiforme y es de tamaño mediano, longitud total preservada 97,5 mm. El cráneo se ha conservado en vista ventral, a partir de este, el eje axial del cuerpo va cambiando de posición desde anterior hacia posterior hasta quedar su aleta caudal expuesta en posición lateral. Lo interesante de este espécimen es que se preservó el basicraneo en vista ventral. Presenta apertura bucal amplia con los maxilares y dentarios completos. Ambos preoperculares, cuadrados-yugales, y radios branquiostegos están completos. Se observa claramente que todas las vértebras presentan los centros vertebrales sin osificar. Se identificaron las aletas pectorales, dorsal y caudal, esta última de forma heterocerca. Los rasgos anatómicos observados en este espécimen confirman su asignación a Chondrostei. Análisis futuros que incluyan una mayor cantidad de ejemplares permitirán una identificación más precisa dentro de este gran grupo de peces.

P. Bona, M. S. De la Fuente and M. A. Reguero

The fossil record of reptiles from the Paleogene of Antarctica is very scarce. Only postcranial fragments of Dermochelyidae turtles have been recovered from several localities on Seymour (Marambio) Island. The fossils previously described include a few isolated carapace ossicles and a small fragment of carapace with four sutured ossicles, and were tentatively assigned to the leatherback turtle Psephophorus, a genus whose species are recorded from the middle to upper Eocene to Pliocene of Europe, New Zealand, and North America. In this contribution we describe two turtle costal plates with a relative big size and smooth decoration, recently recovered from the middle levels of the La Meseta Formation (Eocene), Seymour Island. This new materialrepresents the first record of a turtle with a bony carapace from the Eocene of Antarctica, and it increases the diversity of the group on this continent.

Fuente: XXV Jornadas Argentinas de Paleontología de Vertebrados, San Luis, 2010.

Neuquensaurus, from the Late Cretaceous of Argentina and one of the first dinosaurs described from Patagonia, is one of the most derived sauropod dinosaurs, and its proportions and size place it among the smallest sauropods ever known. In this context, Neuquensaurus is central to understanding late stages of sauropod evolution. This contribution offers a full description of the appendicular skeleton of Neuquensaurus. The anatomical analysis reveals that the appendicular skeleton of Neuquensaurus exhibits unique characteristics only shared with closely related saltasaurine titanosaurs; for example, the laterally directed preacetabular lobe of the ilium, the prominent fibular lateral tuberosity, and the presence of an intermuscular line on the femoral shaft, which is proposed here as a synapomorphy of Saltasaurinae. Neuquensaurus also displays many reversals to primitive character states, such as the presence of a prominent olecranon process of the ulna, a trochanteric shelf, a lesser trochanter and an ischial tuberosity. Additional characters that allow its evaluation in a phylogenetic context are here provided. Among them are the extremely deflected femoral shaft, the elliptical femoral cross−section, and the anterolaterally oriented cnemial crest.

Otero, A. 2010. The appendicular skeleton of Neuquensaurus, a Late Cretaceous saltasaurine sauropod from Patagonia, Argentina. Acta Palaeontologica Polonica 55 (3): 399–426.

Ignacio Cerda and Jaime Powell

The first unambiguous evidence of the presence of osteoderms in sauropod dinosaurs came from the discovery of Saltasaurus loricatus, a titanosaur from the Upper Cretaceous of Argentina. The dermal armor of Saltasaurus is composed of bony plates and small dermal ossicles. Here, we analyze the bone microstructure of these elements and provide information regarding its origin and development. The bony plates are composed almost entirely of reconstructed cancellous bone. Remains of primary bone consist of coarse bundles of mineralized collagenous fibers towards the external surface. Also, woven fibered bone tissue appears in the basal and lateral regions. Dermal ossicles lack secondary remodeling, and their matrix is formed by three orthogonal systems of collagenous fiber bundles. Growth lines are present in both bony plates and ossicles. Bone histology reveals that osteoderms mainly originated through direct mineralization (metaplasia) of the dermis, although other mechanisms are also involved (at least in the origin of dermal plates). The common features of development and integumental location of the osteoderms of Saltasaurus and other non−related vertebrates (e.g., lepidosaurs, crocodylomorphs) are linked to the intrinsic skeletogenic properties of the dermis.

Cerda, I.A. and Powell, J.E. 2010. Dermal armor histology of Saltasaurus loricatus, an Upper Cretaceous sauropod dinosaur from Northwest Argentina. Acta Palaeontologica Polonica 55 (3): 389–398.

Lucio M. Ibiricu, Rubén D. Martínez, Matthew C. Lamanna, Gabriel A. Casal, Marcelo Luna, Jerald D. Harris and Kenneth J. Lacovara

An associated partial postcranial skeleton is described as the third definitive ornithopod dinosaur record from the Upper Cretaceous Bajo Barreal Formation of central Patagonia, Argentina. Specifically, the specimen was recovered from the uppermost Cretaceous (Campanian–?Maastrichtian) Upper Member of the Bajo Barreal exposed on an ephemeral island in the southeastern portion of Lago Colhué Huapi in southern Chubut Province. Identifiable elements of the skeleton include four incomplete dorsal vertebrae, three partial anterior caudal vertebrae, a middle caudal neural arch, an incomplete posterior caudal vertebra, a dorsal rib fragment, the right calcaneum, and portions of the left metatarsal III and right metatarsal IV. Comparisons with corresponding elements in other ornithischians indicate that the material pertains to a medium-sized, non-hadrosaurid ornithopod. In particular, the morphology of the calcaneum is characteristic of ornithopods of this “grade”. The new discovery augments our understanding of the latest Cretaceous terrestrial vertebrate assemblage of central Patagonia and adds to the generally meager record of ornithischians in the Late Cretaceous of the Southern Hemisphere.

Ibiricu, L. M., Martínez, R. D., Lamanna, M. C., Casal, G. A., Luna, M., Harris, J. D., and Lacovara, K. J., 2010. A medium-sized ornithopod (Dinosauria: Ornithischia) from the Upper Cretaceous Bajo Barreal formation of Lago Colhué Huapi, southern Chubut province, Argentina. Annals of CarnegieMuseum 79 (1):39–50.