For the first time, the presence of large bodied herbivorous dinosaurs
in Antarctica has been recorded. Until now, remains of sauropoda -- one
of the most diverse and geographically widespread species of herbivorous
dinosaurs -- had been recovered from all continental landmasses, except
Antarctica. Dr. Ignacio Alejandro Cerda, from CONICET in Argentina, and
his team's identification of the remains of the sauropod dinosaur
suggests that advanced titanosaurs (plant-eating, sauropod dinosaurs)
achieved a global distribution at least by the Late Cretaceous
Sauropoda is the second most diverse group of dinosaurs, with more
than 150 recognized species. It includes the largest terrestrial
vertebrates that ever existed. Although many sauropod remains have been
discovered in North and South America, Africa, Asia, Australia and
Europe, there is no previous record of sauropoda in Antarctica. Other
important dinosaur discoveries have been made in Antarctica in the last
two decades -- principally in the James Ross Basin.Dr. Cerda and
colleagues report the first finding of a sauropod dinosaur from this
continent and provide a detailed description of an incomplete middle-tail vertebra,
recovered from James Ross Island. The specific size and morphology of
the specimen, including its distinctive ball and socket articulations,
lead the authors to identify it as an advanced titanosaur.
These titanosaurs originated during the Early Cretaceous and were the
predominant group of sauropod dinosaurs until the extinction of all
non-bird dinosaurs at the end of the Cretaceous. Although they were one
of the most widespread and successful species of sauropod dinosaurs,
their origin and dispersion are not completely understood.
The authors conclude: "Our discovery, and subsequent report, of these
sauropod dinosaur remains from Antarctica improves our current
knowledge of the dinosaurian faunas during the Late Cretaceous on this
continent."*The Cretaceous Period spanned 99.6-65.5 million years ago,
and ended with the extinction of the dinosaurs.
*Note: The Cretaceous Period spanned 99.6-65.5 million years ago, and ended with the extinction of the dinosaurs.
9 ene 2012
