for National Geographic News
Argentine paleontologists have discovered a 13-foot (4-meter) plant-eating dinosaur with a long neck and small head that roamed the southern tip of South America about 70 million years ago.
The team, led by Fernando Novas of the Argentine Museum of Natural Sciences in Buenos Aires, named the dinosaur Talenkauen santacrucensis. Talenkauen means "small head" in the Aonikenk Indian language.
Talenkauen was an ornithischiandinosaurs that had birdlike hips. Its closest relatives include Hypsilophodon, a quick and agile dinosaur that lived 125 million years ago in Europe, and Iguanodon, a 33-foot (10-meter) herbivore that lived about 125 million years ago in Europe and North America.
The partially preserved skeleton of Talenkauen was found in 2000 in the Patagonia region on a hillside near the southeastern shore of Viedma Lake in Argentina's Santa Cruz Province. The public announcement of the discovery last Friday coincided with publication of a scientific description of the dinosaur in the Argentine paleontology journal Ameghiniana.
Talenkauen was one of just a few ornithischians known from the Cretaceous period in South America. The Cretaceous is what geologists call the period of 144 million to 65 million years ago. It was toward the end of the age of dinosaurs, when modern mammals and birds, flowering plants, and insects started to emerge.
The new find sheds light on the diversification of the plant-eating ornithischians in the southern continents, Novas said.
Patricia Vickers-Richa paleontologist from Monash University in Australia who has extensively studied dinosaurs from the southern continentssaid the find of Talenkauen is an important contribution to understanding the region's taxonomy (scientific classification of plants and animals).
"In this region there are lots of sauropods but not much else [other than] an occasional theropod. To get one in the group Fernando has is most unusual and significant," Vickers-Rich said.
Titanosaurian sauropods were huge plant-eating dinosaurs with long necks and tails like the Jurassic apatosaurs. Theropods were meat-eating dinosaurs with short arms and powerful legs.
The research by Novas and colleagues Andrea Cambiaso and Alfredo Ambrosio is supported by grants from the National Geographic Society's Committee for Research and Exploration and Argentina's National Council of Scientific and Technical Research and National Agency for Scientific and Technological Promotion. Fieldwork was also supported by the Renault and Nissan motor companies of Argentina.
Novas and his colleagues discovered Talenkauen among an abundance of petrified logs of large evergreen trees, which suggests the dinosaur roamed in a forested landscape.
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