Avanza la preparación del primer ejemplar de dinosaurio terópodo recuperado recientemente en la última campaña paleontológica del MAU en La Invernada. Entre los materiales que ya han sido preparados se cuentan: varias costillas cervicales y dorsales, además de vértebras caudales y cervicales. En estos días esta finalizando la preparación de los restos craneanos, que si bien no se encuentra completo, aportarán relevante información. Si bien, aún queda mucho material sin preparar en el laboratorio del museo, y seguramente por extraer del campo, los elementos que ya se disponen ponen en clara evidencia que el ejemplar corresponde a un abelisaurio el cual habría alcanzado unos 5 m de longitud. Los abelisaurios son un grupo de dinosaurios terópodos principalmente gondwánicos, es decir, habitaron el supercontinente de Gondwana, conformado por Sudamérica, África, India, Australia y la Antártida. Recientemente se ha dado a conocer un nuevo abelisaurio, Arcovenator escotae, el primero proveniente de Europa, lo que sugiere algún tipo de conexión biogeográfica entre Europa y Africa a finales del Cretácico. El abelisaurio de La Invernada, proviene de niveles de la Formación Bajo de la Carpa, los mismos niveles de donde fueron recuperados en la misma campaña a unos 300 m de disntancia, al menos dos ejemplares de dinosaurio sauropodo titanosaurio. Estos materiales aportan interesante información respecto de una asociación faunística donde queda demostrado quien cumplía el papel de depredador y quién el de presa. En la medida que los fósiles sean preparados, daremos a conocer más información respecto de este nuevo carnívoro patagónico.

Foto ilustrativa: Sergey Krasovskly


Fernando E. Novas, Federico L. Agnolín, Martín D. Ezcurra, Juan Porfiri and
Juan I. Canale

 Patagonia has yielded the most comprehensive fossil record of Cretaceous theropods from Gondwana, consisting of 31 nominal species belonging to singleton taxa and six families: Abelisauridae, Noasauridae, Carcharodontosauridae, Megaraptoridae nov. fam., Alvarezsauridae, and Unenlagiidae. They provide anatomical information that allows improved interpretation of theropods discovered in other regions of Gondwana. Abelisauroids are the best represented theropods in Patagonia. They underwent an evolutionary radiation documented fromthe Early Cretaceous through tothe latest Cretaceous, and are represented by the clades Abelisauridae and Noasauridae. Patagonian carcharodontosaurids are known from three taxa (Tyrannotitan, Giganotosaurus and Mapusaurus), as well as from isolated teeth, collected from Aptian to Cenomanian beds. These allosauroids constituted the top predators during the mid-Cretaceous, during which gigantic titanosaur sauropodswere the largest herbivores. Megaraptorans have become better documented in recent years with the discovery of more complete remains. Megaraptor, Aerosteon and Orkoraptor have been described from Cretaceous beds from Argentina, and these taxa exhibit close relationships with the Aptian genera Australovenator, from Australia, and Fukuiraptor, from Japan. The Gondwanan megaraptorans are gathered into the newfamily Megaraptoridae, and the Asiatic Fukuiraptor is recovered as the immediate sister taxon of this clade. Although megaraptorans have been recently interpreted as members of Allosauroidea, we present evidence that they are deeply nested within Coelurosauria. Moreover, anatomical information supports Megaraptora as more closely related to the Asiamerican Tyrannosauridae than thought. Megaraptorans improve our knowledge about the scarcely documented basal radiation of Gondwanan coelurosaurs and tyrannosauroids as awhole. Information at hand indicates that South America was a cradle for the evolutionary radiation for different coelurosaurian lineages, including some basal forms (e.g., Bicentenaria, Aniksosaurus), megaraptorans, alvarezsaurids less derived than those of Laurasia, and unenlagiids, revealing that Gondwanan coelurosaurs played sharply differing ecological roles, and that theywere taxonomically as diverse as in the northern continents. The unenlagiids represent an endemic South American clade that has been recently found to be more closely related to birds than to dromaeosaurid theropods. Analysis of the theropod fossil record from Gondwana shows the highest peak of origination index occurred during the Aptian-Albian and a less intense one in the Campanian time spans. Additionally, peaks of extinction index are recognized for the Cenomanian and Turonian-Coniacian time spans. In comparison, the Laurasianpattern differs fromthat of Gondwana in the presence of an older extinction event during the Aptian-Albian time-span and a high origination rate during the Cenomanian time-bin. Both Laurasian and Gondwanan theropod records show a peak of origination rates during the Campanian.

Novas, F.E., Agnolín, F.L., Ezcurra, M.D., Porfiri, J.D., Canale, J.I. 2013. Evolution of the carnivorous dinosaurs during the Cretaceous: The evidence from Patagonia. Cretaceous Research 45:174–215.

William Irvin Sellers1, Lee Margetts, Rodolfo Aníbal Coria, Phillip Lars Manning

Sauropod dinosaurs are the largest terrestrial vertebrate to have lived on Earth. This size must have posed special challenges for the musculoskeletal system. Scaling theory shows that body mass and hence the loads that must be overcome increases with body size more rapidly than either the ability of the muscles to generate force, or the ability of the skeleton to support these loads. Here we demonstrate how one of the very largest sauropods, Argentinosaurus huinculensis (40 metres long, weighing 83 tonnes), may have moved. A musculoskeletal model was generated using data captured by laser scanning a mounted skeleton and assigning muscle properties based on comparative data from living animals. Locomotion is generated using forward dynamic simulation to calculate the accelerations produced by the muscle forces, coupled with machine learning techniques to find a control pattern that minimises metabolic cost. The simulation demonstrates that at such vast body size, joint range of motion needs to be restricted to allow sufficient force generation for an achievable muscle mass. However when this is done, a perfectly plausible gait can be generated relatively easily. Whilst this model represents the best current simulation of the gait of these giant animals, it is likely that there are as yet unknown mechanical mechanisms, possibly based on passive elastic structures that should be incorporated to increase the efficiency of the animal`s locomotion. It is certainly the case that these would need to be incorporated into the model to properly assess the full locomotor capabilities of the animal.

Sellers, W.I., Margetts, L., Coria, R.A. and Manning, P.L. 2013. March of the Titans: The Locomotor Capabilities of Sauropod Dinosaurs. PLoS ONE 8(10): e78733. doi:10.1371/journal.pone.0078733

Lucio M. Ibiricu, Gabriel A. Casal, Rubén D. Martínez, Matthew C. Lamanna, Marcelo Luna, And Leonardo Salgado.

We describe Katepensaurus goicoecheai, gen. et sp. nov., a diplodocoid sauropod dinosaur from the Bajo Barreal Formation (Upper Cretaceous: Cenomanian–Turonian) of south-central Chubut Province, central Patagonia, Argentina. The holotypic specimen is a closely associated partial axial skeleton that includes cervical, dorsal, and caudal vertebrae. The dorsal vertebrae of Katepensaurus exhibit the following distinctive characters that we interpret as autapomorphies: (1) internal lamina divides lateral pneumatic fossa of centrum; (2) vertical ridges or crests present on lateral surface of vertebra, overlying neurocentral junction; (3) pair of laminae in parapophyseal centrodiapophyseal fossa; (4) transverse processes perforated by elliptical fenestrae; and (5) well-defined, rounded fossae on lateral aspect of postzygapophyses. Based on the results of previous phylogenetic analyses, we regard the new taxon as a member of Rebbachisauridae; more specifically, it may pertain to Limaysaurinae, a rebbachisaurid subclade that, to date, is definitively known only from southern South America. As currently understood, the rebbachisaurid fossil record suggests that the clade achieved its greatest taxonomic diversity within a few million years of its extinction during the early Late Cretaceous.

Ibiricu, L.M., Casal, G.A., Martínez, R.D., Lamanna, M.C., Luna, M. And Salgado, L. 2013. Katepensaurus goicoecheai, gen. et sp. nov., a Late Cretaceous Rebbachisaurid (Sauropoda, Diplodocoidea) from central Patagonia, Argentina. Journal of Vertebrate Paleontology 33(6):1351–1366.

Finaliza exitosamente la campaña paleontológica del MAU en Cerro Overo / La Invernada. Luego de trabajar durante quince días, el equipo del Museo Argentino Urquiza integrado por el paleontólogo Leonardo Filippi y los Técnicos Carlos Fuentes y Salvador Palomo, junto al geólogo y Director del MOZ (Museo Olsacher de Zapala) Alberto Garrido y además con la participación del paleontólogo Rubén Juarez Valieri, pudieron realizar dos excavaciones simultaneas que permitieron recuperar los restos parciales de al menos dos dinosaurios saurópodos titanosaurios, un  dinosaurio terópodo y un ejemplar de tortuga. Todos estos ejemplares provienen de niveles del Cretácico Superior, tentativamente de la Formación Bajo de la Carpa. Debido a la cantidad y buena preservación de los materiales, se pretende continuar con las excavaciones el año próximo, las que han sido financiadas gracias al apoyo de la empresa Exxon Mobil.


Lucio M. Ibiricu, Rubén D. Martínez, Gabriel A. Casal, Ignacio A. Cerda

Central Patagonia, Argentina, preserves an abundant and rich fossil record. Among vertebrate fossils from the Upper Cretaceous Bajo Barreal Formation of Patagonia, five individuals of the small, non-avian theropod dinosaur Aniksosaurus darwini were recovered. Group behavior is an important aspect of dinosaur paleoecology, but it is not welldocumented and is poorly understood among non-avian Theropoda. The taphonomic association of individuals from the Bajo Barreal Formation and aspects of their bone histology suggest gregarious behavior for Aniksosaurus, during at least a portion of the life history of this species. Histology indicates that the specimens were juvenile to sub-adult individuals. In addition, morphological differences between individuals, particularly proportions of the appendicular bones, are probably related to body-size dimorphism rather than ontogenetic stage. Gregarious behaviour may have conferred a selective advantage on Aniksosaurus individuals, contributing to their successful exploitation of the Cretaceous paleoenvironment preserved in the Bajo Barreal Formation. The monospecific assemblage of Aniksosaurus specimens constitutes only the second body fossil association of small, coelurosaurian theropods in South America and adds valuable information about the paleoecologies of non-avian theropod dinosaurs, particularly in the early Late Cretaceous of Patagonia.
Ibiricu, L. M., Martínez, R. D., Casal, G. A., and Cerda, I. A. 2013. The Behavioral Implications of a Multi-Individual Bonebed of a Small Theropod Dinosaur. PloS ONE 8(5): e64253. doi:10.1371/journal.pone.0064253

Una importante investigación se lleva adelante en el MAU (Museo Municipal Argentino Urquiza de Rincón de los Sauces, Neuquén); el paleontólogo del Museo de Historia Natural de San Rafael, Mendoza, Marcelo De La Fuente, comenzó con el estudio de varis ejemplares de tortugas fósiles del Cretácico Superior, halladas en zonas próximas a la localidad.
Se están estudiando tortugas del período cretácico que fueron halladas durante varios trabajos de campo realizados por el paleontólogo de Rincón, Leonardo Filippi. Es un material muy interesante, ya que son restos bastante completo y bien preservados de tortugas qu pertenecen a un grupo que tiene representantes actuales. Lo interesante de esto es que se trata de una especie que ha pasado los límites de extinción cretácica-paleocénica, límite que no cruzaron, entre otros grupos, los dinosaurios, por ejemplo.
La idea es profundizar en un estudio que permita elaborar un trabajo científico que documente estos ejemplares, los que se suman a otros vertebrados entre dinosaurios, cocodrilos y serpientes, recuperados en el marco de un proyecto que tiene como objeto conocer la fauna de fósiles del norte neuquino en inmediaciones de Rincón de los Sauces.


 Gerardo Gabriel Zacarías, Marcelo Saúl De La Fuente, Marta Susana Fernández y Alfredo Eduardo Zurita

Se presenta una nueva especie de tortuga terrestre gigante recuperada de la sección superior del miembro inferior de la Formación Toropí/ Yupoí (Pleistoceno tardío, 58–22 ka). El holotipo fue hallado en Arroyo Toropí, 10 km al sur de la localidad de Bella Vista, Provincia de Corrientes, Argentina. Presenta escudos pectorales del plastrón más estrechos en la línea media y expandidos hacia las marginales en sentido antero-posterior, que permite asignarlo al género Chelonoidis fitzinger. Posee caparazón con márgenes laterales no paralelos, placas periféricas del puente lobuladas, una depresión proximal muy marcada con forma subelíptica sobre las placas periféricas III en ambos lados del caparazón dorsal, y un entoplastrón subromboidal proximalmente amplio, con proyección distal que cruza completamente el escudo pectoral, que permiten reconocerlo como una nueva especie, Chelonoidis lutzae sp. nov. El consenso estricto del análisis filogenético del clado Chelonoidis exhibe una politomía entre Ch. lutzae sp. nov., ?Ch. gallardoi (Rovereto), ?Ch. australis (Moreno) y los grupos carbonaria y chilensis. El grupo carbonaria incluye a Ch. denticulata (Linnaeus) y al clado formado por Ch. carbonaria (Spix) y Ch. hesterna (Auffenberg). El grupo chilensis, incluye dos subclados, uno integrado por Ch. chilensis (Gray), Ch. petersi (Freiberg) y Ch. nigra (Quoy y Gaimard), y otro formado por YPFB-PAL 0932 y Ch. gringorum (Simpson). Utilizando la opción “pruned tree” del TNT, se recupera un subclado formado por “tortugas terrestres gigantes continentales extintas” (Ch. lutzae sp. nov. y ?Ch. australis), claramente diferenciado de las tortugas gigantes de Galápagos.
Zacarías, G.G., De La Fuente, M. S., Fernández, M. S. y Zurita, A. E.2013 Nueva especie se tortuga terrestre gigante del Género Chelonoidis fitzinger, 1835 (Cryptodira: Testudinidae), del Miembro Inferior de la Formación Toropí/ Yupoí (Pleistoceno Tardío/ Lujanense), Bella Vista, Corrientes, Argentina. Ameghiniana 50 (3): 298 – 318.


Rodolfo A. Coria, Leonardo S. Filippi, Luis M. Chiappe, Rodolfo García y Andrea B. Arcucci

A new lithostrotian sauropod, the small-sized Overosaurus paradasorum n. gen et sp. from the Anacleto Formation (Cam-panian, Late Cretaceous, Neuquén Group, Patagonia, Argentina) is here described. The specimen (MAU-Pv-CO-439) consists of a fully articulated vertebral series from the 10th cervical to the 20th caudal vertebra, the last cervical ribs, several dorsal ribs in articulation with their respective vertebrae, the complete right ilium and fragments of the left ilium. Overosaurus paradasorum is diagnosed by a unique combination of characters that includes (1) posterior cervical vertebrae with long pre- and postzygapophyses that project beyond the anterior and posterior borders of the centrum, respectively, (2) postspinal lamina absent in all dorsal neural spines, (3) wide and massive 9th and 10th caudal centra that are slightly exca-vated laterally and have relatively flat ventral surfaces, (4) laminar projection on the posterior border of the second and third dorsal rib, (5) ilium proportionally shorter anteroposteriorly and taller dorsoventrally than in other lithostrotians, and (6) the preacetabular process of the ilium strongly deflected laterally and with a ventrolaterally tapering end. Analysis of the phylogenetic relationships of Overosaurus places it within the Aeolosaurini, as the sister taxon of a monophyletic group formed by Aeolosaurus rionegrinus, A. maximus, Gondwanatitan faustoi and Pitekunsaurus macayai. Overosaurus is a new representative of a highly diversified assemblage of Campanian lithostrotians from Patagonia that includes both Aeolosaurini and saltasaurids (e.g. Saltasaurus, Neuquensaurus) this small new taxon falls within the low end of the size spectrum represented by these Late Cretaceous sauropods.

Coria, R. A., Filippi, L. S., Chiappe, L. M., García, R. & Arcucci, A. B. 2013. Overosaurus paradasorum gen. et sp. nov., a new sauropod dinosaur (Titanosauria: Lithostrotia) from the Late Cretaceous of Neuquén, Patagonia, Argentina. Zootaxa 3683 (4): 357-376.

Ariana Paulina Carabajal, Juliana Sterli, Johannes Müller y André Hilger

Turtles are one of the least explored clades regarding endocranial anatomy with few available descriptions of the brain and inner ear of extant representatives. In addition, the paleoneurology of extinct turtles is poorly known and based on only a few natural cranial endocasts. The main goal of this study is to provide for the first time a detailed description of the neuroanatomy of an extinct turtle, the Late Jurassic Plesiochelys etalloni, including internal carotid circulation, cranial endocast and inner ear, based on the first digital 3D reconstruction using micro CT scans. The general shape of the cranial endocast of P. etalloni is tubular, with poorly marked cephalic and pontine flexures. Anteriorly, the olfactory bulbs are clearly differentiated suggesting larger bulbs than in any other described extinct or extant turtle, and indicating a higher capacity of olfaction in this taxon. The morphology of the inner ear of P. etalloni is comparable to that of extant turtles and resembles those of slow-moving terrestrial vertebrates, with markedly low, short and robust semicircular canals, and a reduced lagena. In P. etalloni the arterial pattern is similar to that found in extant cryptodires, where all the internal carotid branches are protected by bone. As the knowledge of paleoneurology in turtles is scarce and the application of modern techniques such as 3D reconstructions based on CT scans is almost unexplored in this clade, we hope this paper will trigger similar investigations of this type in other turtle taxa.

Carabajal AP, Sterli J, Müller J, Hilger A (2013) Neuroanatomy of the Marine Jurassic Turtle Plesiochelys etalloni (Testudinata, Plesiochelyidae). PLoS ONE 8(7): e69264. doi:10.1371/journal.pone.0069264

Juliana Sterli, Marcelo S. De la Fuente e Ignacio A. Cerda
Una nueva especie de meiolaniforme, Trapalcochelys sulcata gen. nov. sp. nov., de la Formación Allen (Campaniano tardío–Maastrichtiano temprano), Patagonia, Argentina, es presentada en este trabajo. Los restos postcraneanos pertenecientes a esta nueva especie son descriptos macroscópicamente (e.g., morfología externa) y microscópicamente (e.g., cortes histológicos del caparazón). Trapalcochelys sulcata gen. nov. sp. nov. comparte con otros meiolaniformes la presencia de surcos entre los escudos marginales marcadamente curvados anteriormente y la ornamentación de las placas dérmicas del caparazón constituida por pequeños forámenes. Esta nueva especie difiere de la otra especie de meiolaniforme del Cretácico Superior de Patagonia —Patagoniaemys gasparinae— en el tamaño general y en la forma de la neural 1. La histología ósea está caracterizada por una estructura diploe, donde una capa externa e interna de tejido compacto circundan una región de hueso esponjoso. El hueso compacto está compuesto mayormente por paquetes entrelazados de fibras estructurales. La abundancia de fibras estructurales en la corteza interna y la presencia de grandes canales vasculares tubulares son los caracteres histológicos mas distintivos de T. sulcata. Además, una revisión exhaustiva de los restos de Meiolaniformes del Cretácico Superior de Sudamérica es presentada. El registro sudamericano conocido de Meiolaniformes del Cretácico Superior está restringido a Argentina y en esta revisión hasta seis localidades han sido reconocidas. Se corrobora que los Meiolaniformes son un componente de la asociación sudamericana Alleniana de tetrápodos de edad campaniana tardía–maastrichtiana temprana.
Sterli, J., De la Fuente, M. S. y Cerda, I. A. 2013. New species of Meiolaniform turtle and a revision of the Late Cretaceous Meiolaniformes of South America. Ameghiniana 50 (2): 240-256.


Marcos G. Becerraa, Diego Pol, Claudia A. Marsicano and Oliver W.M. Rauhut

The recently described Manidens condorensis is one of the most completely known taxa of the family Heterodontosauridae from the southern landmasses. However, some dental aspects are not well known due to preservational problems in the type material. This contribution reports new isolated teeth found in the Canñadón Asfalto Formation (Early-Middle Jurassic). These teeth are referred to Manidens condorensis based on the presence of autapomorphic characters of the unusual dentition of this taxon, such as the highly asymmetric tooth crowns and small crenulations on each denticles. The isolated crowns are well preserved and reveal the presence of undescribed and new autapomorphical features, including apical and basal wear facets on the occlusal surface of isolated crowns and a wear surface also in the caniniform tooth. We carried out statistical analyses (including morphogeometrical and discriminant analyses), using the holotype crowns as a morphological starting point, for characterising shape variation of the crowns along the toothrow and for identifying the position of isolated crowns. These analyses allow defining morphological regions within the postcaniniform toothrow and produce a metrically based discriminant function to predict the hypothetical position of future discoveries, providing a methodological framework that could be applied to other extinct heterodont dinosaurs.

Marcos G. Becerra , Diego Pol , Claudia A. Marsicano & Oliver W.M. Rauhut (2013). The dentition of Manidens condorensis (Ornithischia; Heterodontosauridae) from the Jurassic Cañadón Asfalto Formation of Patagonia: morphology, heterodonty and the use of statistical methods for identifying isolated teeth, Historical Biology: An International Journal of Paleobiology, DOI:10.1080/08912963.2013.794227

Rodolfo García y Leonardo Salgado

The dinosaur record of the Salitral Moreno locality (Río Negro Province, Argentina) is characterized by a high diversity of herbivore taxa, among them hadrosaurs, ankylosaurs, and titanosaur sauropods, but carnivores are rare, consisting of only a few fragmentary bones of small forms. Titanosaurs are represented by Rocasaurus muniozi and Aeolosaurus sp., and at least four other taxa, represented by fragmentary material. The elements preserved include a cervical, dorsal and caudal vertebrae, chevron, humerii, ulnae, radii, metacarpal, femora, tibiae, metatarsal, ischia, pubis, and ilium. The Allen Formation is thought to be correlated with the Marília Formation in Brazil, and their faunas have certain elements in common such as aeolosaurines, but saltasaurines and hadrosaurs, are known exclusively from the Allen Formation. These absences, and particularly that of the saltasaurines, may be because those sauropods originated late in the Cretaceous, probably in southern South America (Northern Patagonia?), and they did not have time to disperse to northern South America.

Garcia, R.A. and Salgado, L. 2013. The titanosaur sauropods from the late Campanian–early Maastrichtian Allen Formation of Salitral Moreno, Río Negro, Argentina. Acta Palaeontologica Polonica 58 (2): 269–284.


Phil R. Bell and Rodolfo A. Coria
Paleoepidemiology (the study of disease and trauma in prehistoric populations) provides insight into the distribution of disease and can have implications for interpreting behavior in extinct organisms. A monospecific bonebed of the giant carcharodontosaurid Mapusaurus (minimum number of individuals = 9) from the Cañaadón del Gato site, Neuquén Province, Argentina (Cenomanian) provides a rare opportunity to investigate disease within a single population of this important apex predator. Visual inspection of 176 skeletal elements belonging to a minimum of nine individuals yielded a small number of abnormalities on a cervical vertebra, two ribs, pedal phalanx, and an ilium. These are attributed to traumatic (two cases), infectious (two cases) and anomalous (one case) conditions in a minimum of one individual. The emerging picture for large theropod (abelisaurids, allosaurids, carcharodontosaurids, tyrannosaurids) populations suggests that 1) osseous abnormalities were relatively rare (7–19% of individuals) but consistently present, and 2) trauma was a leading factor in the frequency of pathological occurrences, evidence of an active, often perilous lifestyle.
Bell, P.R. and Coria R.A. 2013. Palaeopathological Survey of a Population of Mapusaurus (Theropoda: Carcharodontosauridae) from the Late Cretaceous Huincul Formation, Argentina. PLoS ONE 8(5): e63409. doi:10.1371/journal.pone.0063409.

The oldest record of Aeolosaurini

Filippi, L. S., Martinelli, A. G. y Garrido, A. C.
The clade Aeolosaurini is represented by several specimens found, so far, only in Argentina and Brazil. The material reported here corresponds to a sauropod titanosaur consisting of four incomplete anterior caudal vertebrae, from the Narambuena Paleontological Site, Rincón de los Sauces, Neuquén Province, Argentina. The specimen comes from the Plottier Formation (late Coniacian-lower Santonian, Upper Cretaceous), Neuquén Group. The specimen has a combination of features that includes it into the clade Aeolosaurini: anterior caudal centra with anterodorsal margin bent forward; prezygapophyses elongated in anterior caudal, in correlation with the extreme displacement of the neural arch forward; and anteroposteriorly elongated articular facets of prezygapophyses, at least in the anterior caudals. However, it differs from other Aeolosaurini by having postzygapophysis with anteroposteriorly short articular facets, not as elongated in the prezygapophyses. This specimen corresponds not only to the fi rst discovery of an Aeolosaurini in the north of the Neuquén Basin (because Rinconsaurus caudamirus Calvo & Gonzalez Riga has been included in another clade, Rinconsauria), but also the oldest record of the group.
Filippi, L. S., Martinelli, A. G. y Garrido, A. C. 2013. Registro de  un dinosaurio Aeolosaurini (Sauropoda, Titanosauria) en el Cretácico Superior (Formación Plottier) del Norte de la Provincia de Neuquén, Argentina,  y comentarios sobre los Aeolosaurini sudamericanos. Revista Brasilera de Paleontología 16 (1): 147-156.

Laura Codorniú, Luis M. Chiappe, and Fabricio D. Cid.
Two nearly complete skeletons of the filter-feeding pterodactyloid Pterodaustro guinazui from the Lowe Cretaceous of Argentina exhibit clusters of poorly sorted coarse sand to fine gravel inside the abdominal cavity. These stones are interpreted as ingested gastroliths (geogastroliths), which are commonly found in a variety of archosaurs (including birds) but have never before been reported in a pterosaur. The geogastroliths found in these Pterodaustro specimens are interprete as having assisted in the digestion of hard food items such as ‘shelled’ crustaceans that are abundant in the fossil beds of this pterosaur. One of these specimens with geogastroliths has anteriormandibular teeth that are notably thicker than the posterior teeth and are somewhat procumbent. We suggest that these teeth might have facilitated the apprehension of fine gravel.
Codorniú, L., Chiappe, L.M. and Cid, F.D. 2013. First Occurrence of stomach stones in Pterosaurs. Journal of Vertebrate Paleontology 33(3): 647–654.

Eloísa Argañaraz, Gerald Grellet-Tinner, Lucas E. Fiorelli, J. Marcelo Krause y Oliver W. M. Rauhut
Para efectuar una interpretación paleobiológica del primer material oológico hallado en la provincia de Chubut, inferir su escenario paleoambiental y compararlo con huevos de dinosaurios de otras áreas, se describen detalladamente varios fragmentos y dos huevos fósiles incompletos provenientes de la localidad de Huanimán, en el centro-norte de la provincia. El material fue extraído en una arenisca tobácea fina, depositada en facies de planicie de inundación proximal asociada a canales multiepisódicos sinuosos. Esta roca es asignable al Miembro Cerro Castaño de la Formación Cerro Barcino (Aptiano–Albiano). La morfología de las cáscaras es similar a la de otros huevos megalolítidos (un grupo parafilético en la parataxonomía de huevos) de Patagonia tales como los de Auca Mahuevo (Neuquén), identificados como huevos de saurópodos titanosaurios a partir de embriones in ovo, y los de Salitral Moreno (Río Negro). Sin embargo, este nuevo material de Chubut, presenta un nuevo carácter estructural. La red de poros horizontal se ubica debajo de la superficie nodular, a diferencia de los huevos neuquinos donde se encuentra sobre la membrana testácea. Este carácter morfológico y el grosor de cáscara (1.5 mm), sugieren una novedosa adaptación a un ambiente específico de nidificación. Aunque sólo se han encontrado dos huevos aislados en Huanimán, este descubrimiento puede implicar la existencia de un nuevo sitio de nidificación en el área.

Argañaraz, E., Grellet-Tinner, G., Fiorelli, L.E.,  Krause, J. M. y  Rauhut, O.W.M. 2013. Huevos de Saurópodos del Aptiano–Albiano, Formación Cerro Barcino (Patagonia, Argentina): Un enigma Paleoambiental y Paleobiológico. Ameghiniana 50 (1): 33-50.

Durante la primera mitad del mes de abril, el MAU (Museo Municipal Argentino Urquiza), Rincón de los Sauces, Neuquén, reanudó los trabajos de campo en Cañadón Mistringa. En este sitio fue hallado durante el 2012 un enorme ejemplar de dinosaurio saurópodo titanosaurio. Durante estos trabajos se recuperaron algunos huesos que dan cuenta del gran tamaño del animal: una escápula incompleta que se estima superaría el 1,50 m de longitud y una enorme vértebra cervical (bochón de la foto) cuyas medidas estimadas superarían el 1,20 m de ancho, 0,90 m de largo y 1 m de alto aproximadamente. Las tareas de recuperación de este gigante recién comienzan, por lo que todavía será necesario remover varios metros cúbicos de roca, para así, extraer nuevas piezas que permitan estimar el tamaño real del ejemplar, el cual se cree, estaría entre los 30 y 35 m de longitud.

Mariela S. Fenández
El presente estudio es una contribución más al conocimiento de la parataxonomía de las cáscaras de huevos de dinosaurios procedentes del Salitral de Santa Rosa y Salitral Ojo de Agua de la provincia de Río Negro, Argentina. Para dicho trabajo fueron estudiados 4469 fragmentos de cáscaras de huevos de la Formación Allen, Cretácico Superior (Campaniano-Maastrichtiano). Doce de estas cáscaras fueron sometidas a un Análisis de Componentes Principales, para clasificarlas y analizar las relaciones entre los caracteres utilizados comúnmente en las clasificaciones parataxonómicas. Por otra parte se estudiaron 4264 cáscaras con lupa binocular, 57 cáscaras con microscopio óptico y microscopio de polarización y por último 14 cáscaras con microscopio electrónico de barrido. Fueron identificados dos grandes grupos, cáscaras del tipo 1 afines a la oofamilia Megaloolithidae con cinco subtipos y cáscaras del tipo 2, sin subtipos. Los caracteres relevantes encontrados con el estudio de ACP fueron: el espesor de la cáscara, la anchura de las unidades de cáscara, el diámetro de los nódulos y el diámetro de las mamilas. Los diferentes tipos de cáscaras registrados fueron comparados con diversos ootaxones de América del Sur y del resto del mundo.
Fernández, M.S. 2013. Análisis de cáscaras de huevos de Dinosaurios de la Formación Allen, Cretácico Superior de Río Negro (Campaniano-Maastrichtiano): Utilidad de los macrocaracteres de interés parataxonómico. Ameghiniana 50 (1): 79-97.

Mariela S. Fernández, Rodolfo A. García, Lucas Fiorelli, Alejandro Scolaro, Rodrigo B. Salvador, Carlos N. Cotaro, Gary W. Kaiser y Gareth J. Dyke

We report the first evidence for a nesting colony of Mesozoic birds on Gondwana: a fossil accumulation in Late Cretaceous rocks mapped and collected from within the campus of the National University of Comahue, Neuquén City, Patagonia (Argentina). Here, Cretaceous ornithothoracine birds, almost certainly Enanthiornithes, nested in an arid, shallow basinal environment among sand dunes close to an ephemeral water-course. We mapped and collected 65 complete, nearcomplete, and broken eggs across an area of more than 55 m2. These eggs were laid either singly, or occasionally in pairs, onto a sandy substrate. All eggs were found apparently in, or close to, their original nest site; they all occur within the same bedding plane and may represent the product of a single nesting season or a short series of nesting attempts. Although there is no evidence for nesting structures, all but one of the Comahue eggs were half-buried upright in the sand with their pointed end downwards, a position that would have exposed the pole containing the air cell and precluded egg turning. This egg position is not seen in living birds, with the exception of the basal galliform megapodes who place their eggs within mounds of vegetation or burrows. This accumulation reveals a novel nesting behaviour in Mesozoic Aves that was perhaps shared with the non-avian and phylogenetically more basal troodontid theropods.
Fernández MS, García RA, Fiorelli L, Scolaro A, Salvador RB, et al. (2013) A Large Accumulation of Avian Eggs from the Late Cretaceous of Patagonia (Argentina) Reveals a Novel Nesting Strategy in Mesozoic Birds. PLoS ONE 8(4): e61030. doi:10.1371/journal.pone.0061030

Filippi L. S., Cerda I. A. y Garrido, A. C.
Resumen. Se describen osteodermos de un nuevo ejemplar de crocodyliforme hallado en un afloramiento correspondiente a niveles de la Formación Plottier (Coniaciano tardío) de la localidad de Puesto Hernández, en inmediaciones de la localidad de Rincón de los Sauces, Provincia del Neuquén. Los osteodermos estudiados, que son parte del material hallado, están integrados por: región dorso-sacra, osteodermos apendiculares asociados al fémur derecho, región proximoventral de osteodermos caudales articulados y osteodermos aislados. La histología de los osteodermos permitió determinar que están constituidos por una corteza compacta que circunda una región interna más porosa. Fue posible reconocer marcas de crecimiento (annuli) en prácticamente todo el tejido compacto, pudiendo determinarse una edad mínima de 18 años para el espécimen estudiado. Los osteodermos exhiben caracteres que permiten preliminarmente asignar al ejemplar, como un Mesoeucrocodylia cercanamente relacionado con Peirosauridae.

Abstract. Osteoderms of a new crocodyliform specimen recovered from the Puesto Hernández locality are described here, found in sediments of the Plottier Formation (late Coniacian), near Rincón de los Sauces city, Neuquén Province. The studied osteoderms, that are part of the associated material, include: dorso-sacral region, appendicular osteoderms associated to the right femur, proximoventral region of articulated caudal osteoderms, and isolated osteoderms. The histology of the osteoderms allowed determining they have a compact cortex that surrounds a more cancellous internal region. It was possible to recognize growth marks (annuli) in the entire compact tissue, indicating a minimum age of 18 years for the studied specimen. The osteoderms have characters that allow preliminarily assigning the specimen to Mesoeucrocodylia closely related to Peirosauridae.
Filippi, L.S., Cerda, I.A. y Garrido, A. C. 2013 Morfología e histología de los osteodermos de un peirosauridae de la Cuenca Neuquina. Ameghiniana 50 (1):3-13.



Diego Pol, Oliver W. M. Rauhut, Agustina Lecuona, Juan M. Leardi, Xing Xu and James M. Clark

Extant crocodylians have a limited taxonomic and ecological diversity but they belong to a lineage (Crocodylomorpha) that includes basal and rather generalized species and a highly diverse clade, Crocodyliformes. The latter was among the most successful groups of Mesozoic tetrapods, both in terms of taxonomic and ecological diversity. Crocodyliforms thrived in terrestrial, semiaquatic, and marine environments, and their fossil diversity includes carnivorous, piscivorous, insectivorous, and herbivorous species. This remarkable ecological and trophic diversity is thought only to occur in forms with a completely akinetic skull, characterized by a functionally integrated and tightly sutured braincase-quadrate-palate complex. However, the patterns of evolutionary change that led to the highly modified skull of crocodyliforms and that likely enabled their diversification remain poorly understood. Herein, a new basal crocodylomorph from the Late Jurassic of Patagonia is described, Almadasuchus figarii gen. et sp. nov. The new taxon is known from a well-preserved posterior region of the skull as well as other craniomandibular and postcranial remains. Almadasuchus figarii differs from all other crocodylomorphs in the presence of six autapomorphic features, including the presence of a large lateral notch on the upper temporal bar, an otic shelf of the squamosal that is wider than long, a deep subtriangular concavity on the posterolateral surface of the squamosal, and an elongated pneumatopore on the ventral surface of the quadrate. Phylogenetic analysis focused on the origin of Crocodyliformes places Almadasuchus as the sister group of Crocodyliformes, supported by synapomorphic features of the skull (e.g. subtriangular basisphenoid, absence of basipterygoid process, absence of a sagittal ridge on the frontal, and a flat anterior skull roof with an ornamented dorsal surface). New braincase information provided by Almadasuchus and other crocodylomorphs indicates that most of the modifications on the posterior region of the skull of crocodyliforms, including the strongly sutured braincase, quadrate, and the extensive secondary palate appeared in a stepwise manner, and pre-dated the evolutionary changes in the snout, jaws, and dentition. This indicates that the progressively increased rigidity of the skull provided the structural framework that allowed the great ecological diversification of crocodyliforms during the course of the Mesozoic. The phylogenetic pattern of character acquisition inferred for the strongly sutured (akinetic) skull and the appearance of more diverse feeding behaviours that create high mechanical loads on the skull provides another interesting parallel between the evolution of Mesozoic crocodyliforms and the evolutionary origins of mammals.
Pol, D., Rauhut, O.W.M., Lecuona, A., Leardi, J. M., Xu. X. and Clark, J.M. 2013 A new fossil from the Jurassic of Patagonia reveals the early basicranial evolution and the origins of Crocodyliformes. Biological Reviews. doi: 10.1111/brv.12030

Philip J. Currie y Ariana Paulina Carabajal
There were considerable differences in Late Cretaceous faunas of the Northern and Southern Hemispheres, although the differences were breaking down during Campanian and Maastrichtian times with the appearance of hadrosaurids in Antarctica and South America, and titanosaurids in North America. However, theropods continued to be separated into northern and southern faunas until paravians were discovered in the Southern Hemisphere (Novas and Puerta, 1997; Forster et al. 1998; Calvo et al. 2004; Makovicky et al. 2005; Novas and Pol, 2005; Novas et al. 2008). During the 2008 field season, a joint expedition to the Bajo de Santa Rosa (Río Negro, Argentina) recovered a second, slightly smaller specimen of Austroraptor cabazai Novas, Pol, Canale, Porfiri and Calvo, 2008 (Novas et al. 2008; Paulina Carabajal et al., 2009). The specimen was identified on the basis of the morphology of the humerus, metatarsal III and pedal phalanx IV-2 (originally identified as IV-1 in the holotype, MML 195). Although the skeleton is incomplete, it preserves bones (radius, ulna, and elements of the metacarpus, metatarsus and pes) that were not recovered with the holotype of this large dromaeosaurid. The description of this second specimen is intended to complement the description of the holotype (Novas et al., 2008), adding information about the limb morphology, particularly the forelimb and foot of this dinosaur.
Currie, P.J. y Paulina Carabajal, A. 2012. A new specimen of Austroraptor cabazai Novas, Pol, Canale, Porfiri and Calvo, 2008 (Dinosauria, Theropoda, Unenlagiidae) from the Latest Cretaceous (Maastrichtian) of Río Negro, Ameghiniana 49(4): 662-667.

Lucio M. Ibicuru, Rubén D. Martínez y Gabriel A. Casal

The fossil record of pterosaurs is relatively abundant in South America. Remains of this group have been primarily found in Early Cretaceous rocks exposed in two different areas, i.e., in Northeastern Brazil (Kellner and Tomida, 2000) and in San Luis Province, Central Argentina (Bonaparte, 1970). Excepting the records in Neuquén Province, the fossil record of pterosaurs in Patagonia (i.e., Golfo San Jorge and Austral basins) is poor and incomplete (Codorniú and Gasparini, 2007). Continental deposits of the Bajo Barreal Formation (Cenomanian–Turonian) exposed in Central Patagonia, Argentina (Golfo San Jorge Basin), preserve an important record of South American Late Cretaceous vertebrates, particularly dinosaurs (Martínez et al., 2004; Martínez and Novas, 2006; Casal et al., 2007; Ibiricu et al., 2010). This record has been significantly increased over the past decade. The best known assemblages from Bajo Barreal come from the localities known as Estancia Ocho Hermanos and Estancia Laguna Palacios. Herein we report recently identified pterosaur material from rocks of the Bajo Barreal Formation exposed at Estancia Ocho Hermanos and discuss the implications of this material for the Patagonian fossil record of Pterosauria. The fossil is significant because it adds to the generally sparse global record of Cretaceous (especially Late Cretaceous) pterosaurs and constitutes the second most southern occurrence of Pterosauria worldwide. This material confirms the presence of pterosaurs in the Bajo Barreal Formation, increasing the number of taxa in the known fossil fauna from this unit and thus our knowledge of the early Late Cretaceous vertebrate assemblages of Central Patagonia.
Ibicuru,L. M., Martínez, R. D. y Casal, G. A. 2012. The first record of Pterosauria in the Bajo Barreal Formation (Upper Cretaceous), central Patagonia, Argentina. Ameghiniana 49(4): 657-661

Si bien hace tiempo se llevó adelante una reconstrucción en vida de Pitekunsaurus macayai por el Dr. Ezequiel Vera, recientemente el equipo del grupo de investigación científica Eofauna, integrado por Asier Larramendi y Rubén Molina, hizo estimaciones del tamaño real de esta especie de saurópodo de Patagonia. Esta tarea consistió en tomar todas las medidas de los huesos preservados, y realizar comparaciones que llevaron a establecer proporciones que permitieron obtener una estimación lo suificientemente precisa de su tamaño. El tamaño de Pitekunsaurus estaría entre los 10 a 12 m de longitud, datos que resultan coincidentes con las estimaciones que se habían realizado durante el estudio del ejemplar. Otros interesantes trabajos sobre paleorecostrucción pueden verse en www.eofauna.com.

Rodolfo Coria, Bernardo González Riga y Silvio Casadío
Abstract. New studies of a Hadrosauridae specimen collected in the Allen Formation, Late Campanian/Early Maastrichthian from La Pampa Province, Argentina, allow recognizing a new taxon, Lapampasaurus cholinoi gen. et sp. nov., which is diagnosed by the following combination of characters: anterior cervical vertebrae with lateral foramina on the dorsal side of the diapophyses, scapula with laterally sharp deltoid crest and convex dorsal surface, pedal ungual phalanx longer than wide with superficial grooves and foramina, and shallow, longitudinal ventral ridge. The identification of Lapampasaurus as a member of Hadrosauridae is confirmed by the recognition of several synapomorphies, such as cervical neural arches with zygapophysial peduncles that elevate above the neural canal, long and dorsally arched postzygapophyses, coracoid relatively small when compared with the scapula, with concave anterior margin and well developed bicipital knob, and hoof-shaped pedal ungual phalanx. The record of Lapampasaurus in the Late Cretaceous of Patagonia suggests the presence of a more diverse hadrosaurid fauna than previously recorded.
Coria, R. A., González Riga, B. y Casadío, S. 2012. Un nuevo hadrosáurido (Dinosauria, Ornithopoda) de la Formación Allen, Provincia de La Pampa, Argentina. Ameghiniana 49 (4):552-572.

Durante la primera salida de campo del 2013, el equipo del Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén,  recuperó las últimas piezas de un ejemplar de saurópodo juvenil, hallado el año pasado en un nuevo sitio dentro del Yacimiento Narambuena, cuya edad correspondería a la Fm. Anacleto,  Cretácico Superior. Este pequeño ejemplar se encuentra integrado por algunas vértebras, principalmente caudales, huesos de la cadera, del miembro delantero como del trasero. La ausencia de los arcos neurales en las vértbras, como consecuencia de la falta de fusión en estos elementos, como así también el tamaño de las piezas, son una clara evidencia de que se trata de un individuo juvenil de saurópodo que habría tenido al momento de su muerte aproximadamente unos 3 a 4 m de longitud. Los materiales ya han sido preparados por los técnicos del museo, por lo que en los próximos meses, se dará comienzo al estudio de los mismos.