For the first time, researchers have discovered a clue that a large herbivorous dinosaurs lived in Antarctica . On James Ross Island, they found 90 million year old tail vertebrae of aTitanosauriers , a long-necked, quadrupedal herbivore . Among them were giants of the Cretaceous period as more than 20 feet long Brachiosaurus. “This group of dinosaurs has been found on all continents except in Antarctica – until now,” the scientists wrote in the scientific journal “Science”.
Because a large part of the Antarctic continent more than two miles of thick ice is covered, it is difficult for scientists to find evidence of past life there. Even in the summer when ice-free areas along the coast, they usually recieve only few bones remains . Because of the thick frost, and large temperature differences between polar day and polar night, the bones brittle material rapidly destroyed.
The researchers therefore regard it as a godsend, to find 19 centimeters high and 16 centimeters wide vertebrae in the soil of James Ross Island . From the size of the vortex and the shape of the bones, they concluded that there must be a tail’s vertebra of a Titanosauriers. “Only in a single bone, we can not see much, so we know the genus or species of a dinosaur,” says said study researcher Ariana Paulina Carabajal, a paleontologist at the Carmen Funes Municipal Museum in Plaza Huincul, Argentina. But be very sure that it was a Titanosaurier.
Although this group of dinosaurs were among the most common and successful types of sauropod dinosaurs, their origin and their distribution is still not fully explored. “Our discovery shows now that the Titanosaurier were in the upper Cretaceous distributed worldwide on every continent,” Ignacio Cerda wrote from the Universidad Nacional del Comahue in Buenos Aires and his colleagues.
Route of immigration still unclear
It is still unclear when and how the large herbivorous dinosaurs inhabited the Antarctic. During the Cretaceous, the continent was still connected by land connections with Australia and South America. Antarctica was also further north than today and had a much milder climate. “It was so warm enough for these animals to live there,” said Carabajal.
There are currently two hypotheses of when Titanosaurier got into the Antarctic, the researchers say. First, they could have immigrated in the late Cretaceous period, about 90 million years ago, from South America. There was at that time numerous species of this group of dinosaurs.
“The second hypothesis assumes that the Titanosaurier during the early Cretaceous or even earlier, were already present in the Antarctic,” the researchers write. An indication of this was the discovery of Titanosauriern from that time in Australia and New Zealand. Yet it is not clear what assumption is correct agree and the point will probably show only with other findings.
Abdullah AL Abbadi
Source: LiveScience 04 November 2011