BOZEMAN -- New research from Montana State University's Museum of the Rockies and the State Museum of Pennsylvania has unveiled enormous bones from North America's biggest dinosaur.
In a paper published Dec. 6 in Acta Palaeontologica Polonica, MSU researcher Denver W. Fowler and coauthor Robert M. Sullivan from Harrisburg, Pa., describe two gigantic vertebrae and a femur that the team collected in New Mexico from 2003 to 2006. Carrying the vertebrae alone took most of a day and was a "killer" because the paleontologists carried them 1.2 miles through 100-degree heat, Fowler said.
The bones belong to the sauropod dinosaur Alamosaurus sanjuanensis: a long-necked plant eater related to Diplodocus. The Alamosaurus roamed what is now the southwestern United States and Mexico about 69 million years ago.
"Alamosaurus has been known for some time; its remains were first described in 1922 from the Naashoibito beds of New Mexico. Since then, more bones have been discovered in New Mexico, Utah, some really nice material from Texas, and Mexico, including a few partial skeletons," Fowler said.
The sheer size of the new bones caught the researchers by surprise, however.
"We used to think that a fully grown Alamosaurus measured around 60 feet long and weighed about 30 tons; but a 2009 study by another MSU researcher, Dr. Holly Woodward, found that a femur thought to belong to an adult was still growing," Fowler said. "This told us that Alamosaurus got even bigger, but we didn't imagine that it could get quite this big."
How big? The enormity of the new bones puts Alamosaurus in the same size league as other giant sauropods from South America, including Argentinosaurus which weighed about 70 tons, and is widely considered to be the biggest dinosaur of all.
"Over the past 20 years, Argentinean and Brazilian paleontologists have been unearthing bigger
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Montana State University