INVESTIGADORES
EZCURRA Martin Daniel
congresos y reuniones científicas
Título:
A NEW DESERT-DWELLING NOASAURINE THEROPOD FROM THE CAIUÁ GROUP, CRETACEOUS OF SOUTH BRAZIL
Autor/es:
LANGER, M. C.; MARTINS, NEURIDES DE OLIVEIRA; MANZIG, PAULO CÉSAR; FERREIRA, GABRIEL DE SOUZA; MARSOLA, JÚLIO CÉSAR DE ALMEIDA; VIDAL, LUCIANO DA SILVA; LIMA, ROSANA; SANT?ANA, LUCAS CESAR FREDIANI; LORENÇATO, ROSANGELA HONÓRIO DA SILVA; EZCURRA, M. D.
Reunión:
Congreso; SVP meeting; 2019
Resumen:
Noasaurines form an enigmatic group of small theropod dinosaurs knownfrom the Late Cretaceous of Gondwana. They are relatively rare, with notablerecords only in Argentina and Madagascar, and more incomplete remainsreported for Brazil, India, and continental Africa. In south-central Brazil, theBauru Basin has yielded a rich fauna of terrestrial tetrapods, most of which isknown from the fluvial deposits of the Bauru Group. The mainly aeoliandeposits of the Caiuá Group, on the contrary, bear a scarce fossil recordcomposed of rare lizards, turtles, and pterosaurs. We report here the firstdinosaur of the Caiuá Group, which also represents the best-preservedtheropod so far recovered from the entire Bauru Basin. The identified skeletalparts (vertebrae, girdles, limbs, and scarce cranial elements) show that the newtaxon was just over 1 m long, with unique anatomical traits among theropods.Metatarsals II and IV have very lateromedially compressed shafts, as are theblade-like ungual phalanges of the respective digits. This implies that the newdinosaur could have been functionally monodactyl, with a main centralweight-bearing digit, flanked by neighboring elements positioned very closeto digit III or even held free of the ground. Such anatomical adaptation isformerly unrecorded among archosaurs, but was previously inferred fromfootprints discovered during the 1970s in the same beds that yielded the newdinosaur. A phylogenetic analysis nests the new taxon within Noasaurinae,which is unresolved because of the multiple alternative positions thatNoasaurus leali can take. The exclusion of that taxon results in positioningthe new dinosaur as the sister-taxon of the Argentinean Velocisaurus unicus.