36 research outputs found

    Comparative 3D analyses and palaeoecology of giant early amphibians (Temnospondyli: Stereospondyli)

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    Macroevolutionary, palaeoecological and biomechanical analyses in deep time offer the possibility to decipher the structural constraints, ecomorphological patterns and evolutionary history of extinct groups. Here, 3D comparative biomechanical analyses of the extinct giant early amphibian group of stereospondyls together with living lissamphibians and crocodiles, shows that: i) stereospondyls had peculiar palaeoecological niches with proper bites and stress patterns very different than those of giant salamanders and crocodiles; ii) their extinction may be correlated with the appearance of neosuchians, which display morphofunctional innovations. Stereospondyls weathered the end-Permian mass extinction, re-radiated, acquired gigantic sizes and dominated (semi) aquatic ecosystems during the Triassic. Because these ecosystems are today occupied by crocodilians, and stereospondyls are extinct amphibians, their palaeobiology is a matter of an intensive debate: stereospondyls were a priori compared with putative living analogous such as giant salamanders and/or crocodilians and our new results try to close this debate.Peer ReviewedPostprint (published version

    New information on the abelisaurid pedal elements from the Late Cretaceous of NW Madagascar (Mahajanga Basin).

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    An abelisaurid ungual phalanx of pedal digit III from the Late Cretaceous of NW Madagascar is here figured and described for the first time. Other materials include pedal phalanges whose figures and description increase the knowledge on the pes variability of the Malagasy Abelisauridae (e.g., ungual I and phalanx III-1 proportions and structures), support the identification of the pedal elements (e.g., phalanx III-2) recently proposed by Carrano (2007), and render questionable the attribution of some isolated elements to the species Majungasaurus crenatissimus

    First description of theropod remains from the Middle Jurassic (Bathonian) of Madagascar.

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    New theropod remains from the Middle Jurassic (Bathonian) of NW Madagascar are described that include 49 isolated teeth and a dorsal vertebra. Being referable to at least three taxa, they provide a first insight into the high morphological biodiversity in the Middle Jurassic theropods. They may represent the oldest Gondwanan material referable to the Abelisauridae and Coelurosauria found up to today; however, lacking more exhaustive data on theropod dentition, their affinities remain uncertain pending more complete material. Riassunto-Prima descrizione di resti di teropodi provenienti dal Giurassico medio (Bathoniano) del Madagascar

    Crocodyliform affinities for Kemkemia auditorei Cau and Maganuco, 2009, from the Late Cretaceous of Morocco.

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    Kemkemia auditorei Cau & Maganuco, 2009 was recently described as a new genus and species of theropod dinosaur on the basis on an isolated distal caudal vertebra. The holotype and only known specimen comes from Kem Kem beds (Upper Cretaceous) of Morocco. In the present paper we review the phylogenetic position of Kemkemia and we conclude that this taxon belongs to Crocodyliformes. It shares with crocodyliforms the presence of a concavity at the posterolateral margin of neural spines, an inflated neural canal, and reduced prezygapophyses, among other traits. This combination of characters clearly distinguishes Kemkemia from theropod dinosaurs. In this way, Kemkemia is here considered as a Crocodyliformes incertae sedis, and based on the absence of unique characters, the genus and species Kemkemia auditorei is proposed as a nomen dubium

    New information on the skull of the enigmatic theropod Spinosaurus with remarks on its size and affinities

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    Evidence of large theropods from the Middle Jurassic of the Mahajanga basin, NW Madagascar, with implications for the ceratosaurian pedal ungual evolution.

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    Two large theropod remains from the Middle Jurassic (Isalo IIIb, Bathonian) of the Mahajanga Basin, NW Madagascar, are here described. They consist of a large tooth crown and a pedal ungual. The tooth is similar to the teeth of some basal tetanuran theropods, but we cautiously refer it to Theropoda incertae sedis. The pedal ungual, pertaining to a close relative of the abelisauroids but not to a member of the Abelisauroidea, shows that non-abelisauroid ceratosaurian theropods were present in the Middle Jurassic of Madagascar and provides new insight into the evolution of the ceratosaurian pedal unguals. Both remains reveal the large body size attained by the Middle Jurassic Malagasy theropods
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