Función en las extremidades anteriores de Monoykus olecranus (resúmen)

Function in the stunted forelimbs of Mononykus olecranus (Theropoda), a dinosaurian anteater. Senter, P. (2005). Paleobiology 31(3): 373-381.

Abstract: "Mononykus olecranus, a theropod dinosaur from the Upper Cretaceous of Mongolia, exhibits reduced forelimbs with a single functional digit. These bizarre forelimbs have aroused great curiosity as to the behavior of the animal, but until now no functional study on the forelimbs of Mononykus has been undertaken. Here I show that the orientation and range of motion in the forelimb elements of Mononykus are such that the humeri sprawl laterally, the antebrachia are held subvertically, the palms face ventrally, and intramanual movement is restricted to subparasagittal motion. This is a radical departure from the typical theropod condition, in which the palms face medially and intramanual movement is transverse. The results of this study confirm that the forelimbs of Mononykus could not have been used to grasp prey or dig burrows, but were well suited for scratch-digging or hook-and-pull movements such as are used by extant anteaters and pangolins to open tough insect nests. Mononykus likely occupied a niche equivalent to that of an anteater or pangolin, an unusual niche for a dinosaur."

Nuevos restos de Ornitisquio en el sur de Africa (Abstarcto)

NEW ORNITHISCHIAN REMAINS FROM THE UPPER ELLIOT FORMATION (LOWER JURASSIC) OF LESOTHO AND STRATIGRAPHICAI, DISTRIBUTION OF SOUTHERN AFRICAN FABROSAURIDS

FABIEN KNOLL, BERNARD BATTAIL
Knoll, F., Battail, B., 2001. New ornithischian remains from the Upper Elliot Formation (Lower Jurassic) of Lesotho and stratigraphical distribution of southern African fabrosaurids.

Abstract: Unpublished postcranial dinosaur material from the Upper Elliot Formation (Hettangian) of Likhoele Mountain (Mafeteng district, Lesotho) is described. The bone assemblage includes elements from both the axial (centra) and appendicular (ilium, femora, tibiae, fibula) skeleton, from, at least, three individuals. Although being clearly ornithischian, the specimens do not belong to heterodontosaurids. They rather appear close to Lesothosaurus diagnosticus. The stratigraphical distribution of southern African fabrosaurids is also discussed on the basis of both the skeletal and ichnological record. © 2001 Éditions scientifiques et m6dicales Elsevier SAS

Nuevo Hadrosaurio Primitivo (abstracto)

A new primitive hadrosauroid dinosaur from the Early Cretaceous of Inner Mongolia (P.R. China)

Pascal Godefroit, Hong Li, Chang-Yong Shang
a Department of Palaeontology, Institut royal des sciences naturelles de Belgique, rue Vautier 29, 1000 Bruxelles, Belgium Inner Mongolia Museum, Xinhua street 2, Hohhot 010020, People’s Republic of China Received March 2005; accepted 5 July 2005

Abstract: The right dentary of a new hadrosauroid dinosaur, Penelopognathus weishampeli, has been discovered in the Bayan Gobi Formation (Albian, Lower Cretaceous) of Inner Mongolia (P.R. China). This new taxon is characterised by its elongated, straight dental ramus, whose lateral side is pierced by about 20 irregularly distributed foramina. Its dentary teeth appear more primitive than those of Probactrosaurus, but more advanced than those of Altirhinus, both also from the Lower Cretaceous of the Gobi area. Non-hadrosaurid Hadrosauroidea were already well diversified in eastern Asia by Early Cretaceous time, suggesting an Asian origin for the hadrosauroid clade.

To cite this article: P. Godefroit et al., C. R. Palevol 4 (2005).
© 2005 Published by Elsevier SAS on behalf of Académie des sciences.

Redescripción de Nemegtosaurus (Abtracto)

Wilson, J.A. (2005). Redescription of the Mongolian sauropod "Nemegtosaurus mongoliensis" Nowinski (Dinosauria: Saurischia) and comments on Late Cretaceous sauropod diversity. Journal of Systematic Palaeontology 3: 283-318.

Abstract: "The isolated skulls of "Nemegtosaurus mongoliensis" and "Quaesitosaurus orientalis" from the Nemegt Basin of Mongolia are among the most complete sauropod cranial remains known from the Late Cretaceous, yet their evolutionary relationships to other neosauropods have remained uncertain. Redescription of the skull of "Nemegtosaurus" identifies key features that link it and its closely related counterpart "Quaesitosaurus" to titanosaur sauropods. These include a posterolaterally orientated quadrate fossa, `rocker'-like palatobasal contact, pterygoid with reduced quadrate flange and a novel basisphenoid–quadrate contact. Other features are exclusive to "Nemegtosaurus" and "Quaesitosaurus", such as the presence of a symphyseal eminence on the external aspect of the premaxillae, a highly vascularised tooth bearing portion of the maxilla, an enclosed `maxillary canal', orbital ornamentation on the postorbital, prefrontal and frontal, exclusion of the squamosal from the supratemporal fenestra and dentary teeth smaller in diameter than premaxillary and maxillary teeth.

"Re-examination of Late Cretaceous sauropod distributions in the light of this well-supported phylogenetic hypothesis has important implications for their diversity at the end of the Mesozoic in Asia and elsewhere. Cretaceous Asian sauropod faunas consist solely of titanosauriforms, which probably migrated there from other landmasses during the Late Jurassic, during which time neosauropods were absent from Asia. Globally, narrow-crowned titanosaurs and rebbachisaurids radiated during the Cretaceous, but only titanosaurs survived into the latest Cretaceous. These late-surviving sauropods flourished on most continental landmasses until the end of the Maastrichtian."

Amurosaurus riabinini

Un equipo belga de paleontólogos descubrió, cerca del río Amour, en la frontera entre Rusia y China, un nuevo ejemplar de dinosaurio del grupo de los hadrosauros.

El equipo, compuesto por once aficionados y cuatro profesionales, que estaba dirigido por el paleontólogo Pascal Godefroit, del Instituto Real de Ciencias Naturales de Bélgica, realizó durante dos semanas excavaciones en la localidad rusa de Blagoveschensk, informó ayer un portavoz del organismo científico.

El mayor descubrimiento ha sido un gran número de huesos que pertenece a una especie hasta ahora desconocida de hadrosauro, que los investigadores han bautizado como Amurosaurus riabinini, por el nombre del río en el que fue encontrado y el del paleontólogo Andrey Riabinin.

En sus excavaciones, el equipo encontró varias costillas y vértebras, un radio, tres tendones, un pequeño hueso de una pata o una mano; una parte de mandíbula y de pómulo, así como otros huesos todavía no identificados.

Los huesos descubiertos serán analizados en Bélgica y luego devueltos a Rusia, aunque en el Museo de Ciencias Naturales de Bruselas se expondrán copias en escayola, se indica.

El equipo de paleontólogos también encontró en Blagosveschensk vértebras de algunos saurópodos y, según Godefroit, es la primera vez que se hallan vestigios de este animal en esa zona.

La desaparición de los dinosaurios, hace unos 65 millones de años, es todavía un enigma científico, pero el descubrimiento de ese nuevo ejemplar apunta a que poco antes de aquella remota época la especie no se estaba extinguiendo, lo que reafirmaría la teoría de un fin súbito debido a una catástrofe, como el impacto de un meteorito, según indica la versión científica acerca del que formó el cráter de Chicxulub.

Fuente: Diario de Yucatán