Washington: Researchers have identified and named a 83-million-year-old species of a rare, primitive duck- billed dinosaur, after studying its fossils discovered in the eastern United States.
This new discovery also shows that duck-billed dinosaurs originated in the eastern US, what was then broadly referred to as Appalachia, before dispersing to other parts of the world.
"This is a really important animal in telling us how they came to be and how they spread all over the world," said Gregory Erickson, a professor at the Florida State University. They named the new dinosaur Eotrachodon orientalis, which
means "dawn rough tooth from the east."
This duck-billed dinosaur - also known as a Hadrosaurid - was probably 20 to 30 feet long as an adult, mostly walked on its hind legs though it could come down on all four to graze on plants with its grinding teeth, and had a scaly exterior.
A large crest on the nose, plus indentations found in the skull and its unique teeth alerted the researchers from McWane Science Centre in US and the University of Bristol in UK that the skeleton they had was something special.
The skeletal remains of this 83-million-year-old dinosaur were originally found by a team of amateur fossil enthusiasts alongside a creek in Alabama in marine sediment. The dinosaur likely was washed out to sea by river or stream sediments after it died, researchers said.
Among the recovered remains of this new dinosaur are a complete skull, dozens of backbones, a partial hip bone and a few bones from the limbs. It is one of the most complete dinosaur skeletons ever to be found in the eastern US.
Its teeth, which show this dinosaur's remarkable ability to grind up plants in a manner like cows or horses, were present in early hadrosaurids, allowing them to consume a wide variety of plants as the group radiated around the world. During the late Cretaceous Period, roughly 85 million years ago, North America was divided in half by a 1,000 mile ocean that connected the Gulf of Mexico to the Arctic Ocean.
This body of water created two North American landmasses, Laramidia to the west and Appalachia to the east. "For roughly 100 million years, the dinosaurs were not able to cross this barrier," said Jun Ebersole, director of collections at McWane Science Centre.
"The discovery of Eotrachodon suggests that duck-billed dinosaurs originated in Appalachia and dispersed to other parts of the world at some point after the seaway lowered, opening a land corridor to western North America," Ebersole
Erickson found it difficult to pinpoint the exact age of the dinosaur because no growth lines appeared in the bone samples. The study was published in the Journal of Vertebrate Paleontology.