Filippi, L., Barrios, F. y Arcucci, A.
La Formación Bajo de la Carpa (Santoniano) de Norpatagonia es una unidad muy fosilífera, que ha brindado restos de peces, quelonios, serpientes, dinosaurios saurópodos, terópodos avianos y no-avianos, y principalmente cocodrilos. En la localidad de Cerro Overo, al sudoeste de Rincón de los Sauces, provincia del Neuquén, hasta el momento esta unidad solo brindó restos de Sauropoda (Overosaurus paradasorum Coria et al., 2013). En esta contribución se da a conocer el primer registro de un Crocodyliforme Mesoeucrocodylia proveniente de dicha localidad. El espécimen  corresponde a la mitad anterior de ambas ramas mandibulares articuladas, integradas cada una por los dentarios con algunos dientes preservados, y los espleniales. En base a comparaciones encontramos similitudes morfológicas con Peirosauridae: por la presencia de dientes zifodontes, sínfisis esplenial y foramen intermandibular oral próximo a la región sinfiseal, particularmente de mandíbula elongada antero-posteriormente, de forma espatulada en su extremo más anterior, comprimida dorso-ventralmente, y con contacto dentario-esplenial en la región sinfiseal en forma de cuña y extendido anteriormente. La morfología recuerda a Pepesuchus Campos et al., 2011, y principalmente a Itasuchus Price, 1955, que los diferencia de otros peirosáuridos (e.g. Gasparinisuchus Martinelli et al., 2012 y Montealtosuchus Carvalho et al., 2007), que presentan mandíbula más robusta con una región sinfiseal tan ancha como larga, y superficie dorsal cóncava. Sin embargo, la ausencia de alvéolos confluentes en el material de Cerro Overo sugiere que se trata de un nuevo taxón, lo que aumentaría la diversidad de Peirosauridae en el Cretácico de Patagonia.
11º Congreso de la Asociación Paleontológica Argentina, Gral. Roca, Río Negro, Argentina, 2016.

 
Filippi, L.,  Juárez Valieri, R., Gallina, P., Méndez, A., Gianechini, F. y Garrido, A.


Paleontological fieldworks carried out on upper section of the Bajo de la Carpa Formation (Santonian, Upper Cretaceous) at La Invernada area, near  Rincón de los Sauces city (northeast Neuquén Province), result in the discovery of several specimens of derived titanosaurs, belonging to multiple taxa. One of them, consists of an articulated modest-sized individual with a nearly complete skull, the axial sequence from the atlas to the last sacral vertebrae with their respective ribs, and both ilia.This sequence is composed by thirteen cervical, ten dorsal and six sacral vertebrae. The skull displays a spatulate snout morphology, with a straight anterior margin, similar to the morphology previously recognized in other titanosaurs such as Antarctosaurus, Bonitasaura and Brasilotitan. The neurocranial morphology is highly derived compared with other titanosaur taxa with well-known skulls such as Sarmientosaurus, Nemegtosaurus, Tapuiasaurus and Rapetosaurus, with displaced frontals located behind the orbits, resulting in an opposite position to the anterior margin of the snout. The occipital condyle is not preserved, but the location of the neurocranial elements and the atlas-axis complex (found in anatomical position) allow to infer a nearly perpendicular position for the tooth row respect to the cervical sequence. This particular condition, confirmed for first time in a derived titanosaur, is morphologically convergent with derived rebbachisaurids such as Nigersaurus. Besides, their respective biochrons are in agreement with the paleoecological niche replacement of the rebbachisaurids by the spatulate snouted titanosaurs in South America, as previously suggested in the post Turonian faunal turnover.
 
11º Congreso de la Asociación Argentina de Paleontología, Gral. Roca, Río Negro, Argentina 2016.
 
 

 
El equipo del Museo Argentino Urquiza (Rincón de los Sauces, Neuquén, Argentina)  realizó trabajos preliminares en el sitio de Cañadón Mistringa, para despejar varias toneladas de roca que cubrían un ejemplar de saurópodo parcialmente recuperado. Esta tarea, llevada adelante gracias al apoyo logístico del sector de Obras Públicas de la Municipalidad de Rincón de los Sauces, permitirá agilizar notablemente los trabajos de campo. Llega la época de campañas y la posibilidad de extraer definitivamente todo el material restante de este enorme dinosaurio.

A Jurassic pterosaur from Patagonia

 
 
Pterosaurs are an extinct group of highly modified flying reptiles that thrived during the Mesozoic. This group has unique and remarkable skeletal adaptations to powered flight, including pneumatic bones and an elongate digit IV supporting a wing-membrane. Two major body plans have traditionally been recognized: the primitive, primarily long-tailed paraphyletic “rhamphorhynchoids” (preferably currently recognized as non-pterodactyloids) and the derived short-tailed pterodactyloids. These two groups differ considerably in their general anatomy and also exhibit a remarkably different neuroanatomy and inferred head posture, which has been linked to different lifestyles and behaviours and improved flying capabilities in these reptiles. Pterosaur neuroanatomy, is known from just a few three-dimensionally preserved braincases of non-pterodactyloids (as Rhamphorhynchidae) and pterodactyloids, between which there is a large morphological gap. Here we report on a new Jurassic pterosaur from Argentina, Allkaruen koi gen. et sp. nov., remains of which include a superbly preserved, uncrushed braincase that sheds light on the origins of the highly derived neuroanatomy of pterodactyloids and their close relatives. A µCT ray-generated virtual endocast shows that the new pterosaur exhibits a mosaic of plesiomorphic and derived traits of the inner ear and neuroanatomy that fills an important gap between those of non-monofenestratan breviquartossans (Rhamphorhynchidae) and derived pterodactyloids. These results suggest that, while modularity may play an important role at one anatomical level, at a finer level the evolution of structures within a module may follow a mosaic pattern.
 
Codorniú L, Paulina Carabajal A, Pol D, Unwin D, Rauhut OWM. (2016) A Jurassic pterosaur from Patagonia and the origin of the pterodactyloid neurocranium. PeerJ 4:e2311

Nuevos hallazgos en La Invernada

 
 
El pasado fin de semana, el MAU, Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén, Argentina,  realizó la evaluación de una denuncia de hallazgo de restos fósiles en el área La Invernada. Después de transitar por un camino de muy dificil acceso, se pudo dar con el lugar exacto de donde provenian los restos recuperados. Los materiales entregados al Museo correspondían a tres de los cinco huesos metacarpianos de una pata delantera de un dinosaurio saurópodo. La evaluación realizada en el lugar permitió determinar que el resto de los huesos faltantes aún estaban in situ, los cuales se encontraban muy bien preservados y articulados con el resto de dicha pata. En futuras salidas, el resto de los huesos serán recuperados y se evaluará si puede que el resto del dinosaurio se encuentre bajo la roca.


Rodolfo A. Coria and Philip J. Currie

A skeleton discovered in the Upper Cretaceous Sierra Barrosa Formation (Turonian-Coniacian) of Neuquén Province, Argentina represents a new species of theropod dinosaur related to the long snouted, highly pneumatized Megaraptoridae. The holotype specimen of Murusraptor barrosaensis n.gen et n.sp. includes much of the skull, axial skeleton, pelvis and tibia. Murusraptor is unique in having several diagnostic features that include anterodorsal process of lacrimal longer than height of preorbital process, and a thick, shelf-like thickening on the lateral surface of surangular ventral to the groove between the anterior surangular foramen and the insert for the uppermost intramandibular process of the dentary. Other characteristic features of Murusraptor barrosaensis n.gen. et n. sp. include a large mandibular fenestra, distal ends of caudal neural spines laterally thickened into lateral knob-like processes, short ischia distally flattened and slightly expanded dorsoventrally. Murusraptor belongs to a Patagonian radiation of megaraptorids together with Aerosteon, Megaraptor and Orkoraptor. In spite being immature, it is a larger but more gracile animal than existing specimens of Megaraptor, and is comparable in size with Aerosteon and Orkoraptor. The controversial phylogeny of the Megaraptoridae as members of the Allosauroidea or a clade of Coelurosauria is considered analyzing two alternative data sets.

Coria RA, Currie PJ (2016) A New Megaraptoran Dinosaur (Dinosauria, Theropoda, Megaraptoridae) from the Late Cretaceous of Patagonia. PLoS ONE 11(7): e0157973. doi:10.1371/ journal.pone.0157973


Sebastián Apesteguía, Nathan D. Smith, Rubén Juárez Valieri, Peter J. Makovicky

Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit.

A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton.

Apesteguía S, Smith ND, Juárez Valieri R, Makovicky PJ (2016) An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina. PLoS ONE 11(7): e0157793. doi:10.1371/journal.pone.0157793

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