North America's Biggest Dinosaur Unearthed in New Mexico

Nate Carroll, left, and Liz Freedman, a doctoral student in Jack Horner's paleontology laboratory, pose with the complete reconstruction of the neck vertebra of an Alamosaurus. (Denver Fowler/Montana.edu)

North America's biggest dinosaur has been unearthed. And it looks like it once called New Mexico home.

The revelation of the massive titanosaurus was documented in a recent issue of Acta Palaeontologica Polonica published on Dec. 6. Co-authors Denver Fowler, a researcher from Montana State University, and Robert M. Sullivan, senior curator of paleontology and geology at the State Museum of Pennsylvania, Harrisburg describe their discovery of an enormous vertebra from a sauropod dinosaur known as Alamosaurus sanjuanensis.

A cousin of the Diplodocus, the Alamosaurus habited the New Mexico region about 69 million years ago.

"When we got back to camp, we started thinking: How did this compare to the biggest specimens from South America?" Fowler told FoxNews.com. "This was so much bigger than the other material of Alamosaurus that had been found up to this time."

Fowler and Sullivan stumbled upon the bones during a dig in the New Mexico desert back in 2004. At first, no digging was necessary since the rock had eroded away enough to expose the bones to the air.

But after the full bone had been freed, Fowler said the trip back to the truck was the hardest part of the entire process.

"There was only two of us out there, and it was about 1.2 miles," Fowler told FoxNews.com. "It was pretty flat terrain, so it wasn't too difficult once we got to the top of the hill where it was exposed. But it was so heavy, and it was usually over 100 Fahrenheit. They say it's a dry heat, but it's always in direct sunlight."

"Dinosaurs never die in the shade," Fowler added.

The Alamosaurus vertebra that Fowler and Sullivan found puts the dinosaur in the same category as other Titanosaurus sauropods discovered in South America – the Argentinosaurus and the Puertasaurus which both could weigh up to 80 – 100 metric tons. Fowler says that the Alamosaurus they discovered could potentially be the same size.

"This is a neck vertebra and the only neck vertebrae of Alamosaurus that have been described are actually quite small individuals from Texas," Fowler told FoxNews.com. "One of the measurements we can take from it is the width of the condyles of the back end of the vertebra. We have a width of about 50 cm for that."

"Argnetinasaurus is certainly known from very fragmentary remains." Fowler continued. "They have a backbone from the middle of the back - the dorsal series we call it. And that's the same sort of 50 cm width."

With the discovery of such a large specimen, new questions have emerged as to the behavior of sauropods in North America. These dinosaurs are found primarily in the south, only getting as far north as Utah, leading Fowler and other researchers to wonder about their preferred environment.

"Maybe they didn't like the environment up there," Fowler told FoxNews.com. "Perhaps they actually emigrated in from South America during this time, and maybe they just haven’t got as far north quite yet. So we can start to ask questions like that. The more material we find the more comparisons we can make."

And Fowler is eager to make more comparisons. Now that the Alamosaurus's size has been confirmed and documented, Fowler is ready to get back out to the desert to see what else is out there. But he’s hoping he can have a bit more people with him.

"We only usually have two or three people out there, so there's a limit to how much you can collect," Fowler told FoxNews.com. "It would be great to go back to the site where the actual bone was found cause there may well be more of that large individual at that site."

"We'd have to dig and get permission, but it’s pretty exciting to think there might be more there."