Nouveaux dinos

Posté par Damien35 il y a 17 ans

UBERABATITAN RIBEIROI, A NEW TITANOSAUR FROM THE MARÍLIA FORMATION (BAURU GROUP, UPPER CRETACEOUS), MINAS GERAIS, BRAZIL (p 881-901)
LEONARDO SALGADO, ISMAR DE SOUZA CARVALHO
Abstract: A new Late Cretaceous titanosaur sauropod from the Bauru Basin of Brazil, Uberabatitan ribeiroi gen. et sp. nov., represented by at least three specimens, is described. The material comes from a level of coarse sandstone within the Serra da Galga sequence in Uberaba County, Minas Gerais State. The fossiliferous strata belong to the Marília Formation (Serra da Galga Member), Bauru Group, considered to be Maastrichtian in age. The fossils occur in the uppermost levels of the above-mentioned unit; thus, Uberabatitan ribeiroi is the youngest titanosaur to have been recorded from the Bauru Basin. The autapomorphies that support the new species are: (1) anterior and mid-cervicals with postzygodiapophyseal lamina (podl) segmented in zygapophyseal and diapophyseal laminae, of which the first extends rostrodorsally over the second; (2) mid-dorsals with a robust lateral lamina formed mainly by a diapophyseal lamina (probably homologous to the postzygodiapophyseal lamina), and, to a lesser extent, by a relic of the spinodiapophyseal lamina (spdl); (3) mid (and probably posterior) dorsals with accessory neural laminae, which are lateral to the prespinal lamina, and probably homologous to the spinoprezygapophyseal laminae (sprl); (4) mid-caudal centra with deeply excavated lateral faces; (5) pubis very thick and robust, with a very stout longitudinal crest on its external (ventral) face; and (6) proximal end of the tibia with a prominent lateral protuberance, which articulates with an equally prominent medial knob of the fibula. The titanosaurian assemblage at Uberaba includes, apart from U. ribeiroi, well-preserved specimens assigned to species of uncertain affinities (Trigonosaurus pricei and Baurutitan britoi), as well as a few vertebrae assigned to aeolosaurines.

A NEW, LARGE ORNITHOMIMID FROM THE CRETACEOUS DINOSAUR PARK FORMATION OF ALBERTA, CANADA: IMPLICATIONS FOR THE STUDY OF DISSOCIATED DINOSAUR REMAINS (p 983-997)
NICK LONGRICH
Abstract: Only two ornithomimid genera, Ornithomimus and Struthiomimus, are currently known from the Upper Cretaceous of North America. However, a number of ornithomimid elements from Alberta's Dinosaur Park Formation (Upper Campanian), cannot be assigned to either Ornithomimus or Struthiomimus. These bones, including a frontal, caudal vertebrae, and unguals of the manus and the pes, come from animals significantly larger than any previously known Judithian ornithomimid. The frontal exhibits several unusual features, including transverse expansion over the prefrontals, and extreme reduction of the supratemporal fossae. Caudal vertebrae are characterized by neural arches that are posteriorly shifted and transversely expanded. Manual unguals possess a highly concave articular surface, a flexor tubercle divided by a sulcus, and a broad claw. Pedal unguals display highly concave articular surfaces, and a ridge-like flexor tubercle dividing a deep ventral fossa. Although it is difficult to know whether these elements represent a single taxon, this is currently the most parsimonious hypothesis. This study demonstrates how isolated dinosaur bones can extend our knowledge of dinosaur faunas.

PHYLOGENETIC ANALYSIS OF REPRODUCTIVE TRAITS OF MANIRAPTORAN THEROPODS AND ITS IMPLICATIONS FOR EGG PARATAXONOMY (p 807-816)DARLA K. ZELENITSKY, FRANÇOIS THERRIEN
Published Online: Apr 14 2008 12:00AM
DOI: 10.1111/j.1475-4983.2008.00770.x
Abstract: A phylogenetic analysis of reproductive and oological (egg) traits of theropod taxa allows determination of the sequence in which these traits evolved in Theropoda. Our results indicate that several avian reproductive traits, such as adults sitting on eggs, asymmetrical eggs, unornamented eggshell surface, and complex eggshell ultrastructure, were already present in non-avian maniraptorans, and could have evolved in more basal theropods. In addition, non-avian maniraptorans laid two eggs at a time and orientated their eggs subvertically or subhorizontally in their nests, features not retained by neornithine birds. Based on our cladistic analysis it is also possible to infer the phylogenetic affinity of ootaxa of unknown parentage: Protoceratopsidovum was laid by a maniraptoran more derived than oviraptorids, and Parvoolithus probably belonged to a Cretaceous bird. Finally, our analysis reveals that many of the high-level categories of egg parataxonomy (morphotypes and basic types) are unnatural groupings (i.e. non-monophyletic). We recommend that these high-level categories be abandoned because oofamilies are sufficient to categorize egg taxa.

A NEW BASAL LINEAGE OF EARLY CRETACEOUS BIRDS FROM CHINA AND ITS IMPLICATIONS ON THE EVOLUTION OF THE AVIAN TAIL (p 775-791)CHUNLING GAO, LUIS M. CHIAPPE, QINJING MENG, JINGMAI K. O'CONNOR, XURI WANG, XIAODONG CHENG, JINYUAN LIU
Published Online: Jul 15 2008 3:38AM DOI: 10.1111/j.1475-4983.2008.00793.x
Abstract: We report on a new Early Cretaceous bird from China that sheds significant light on the evolutionary transition between primitive birds with a long bony tail and those with a short tail ending in a pygostyle. A cladistic analysis of basal birds supports the placement of the new fossil as the sister-taxon of all pygostylians. Possessing a unique hand morphology with a phalangeal formula of 2-3-3-x-x and a reduced number of caudal vertebrae lacking a pygostyle, the new specimen reveals anatomical information previously unknown and increases the taxonomic diversity of primitive, non-pygostylian birds. We infer from the specimen that during the evolution of the avian tail, a decrease in relative caudal length and number of vertebrae preceded the distal fusion of caudals into a pygostyle. [Zhongornis (dinodata) ou Hongornis (dinogenera) haoae]

Posté par Markvantomme il y a 17 ans

Vive, encore une venu de mon coin

Posté par Dinofan il y a 17 ans

Il existe une traduction on peut trouver ces infos sur futurascience ? (parce que "l'outil de traduction Yahoo Babel Fish" c'est pas ce qui a de mieux pour traduire des dossier scientifique)

Posté par Dinomaster il y a 17 ans

Le "LARGE ORNITHOMIMID " il a un nom ?

Posté par Tikémi il y a 17 ans

Non, il est "indet." dans l'article aussi.