A dog-sized dino was found in Texas, adds to debate about dinosaur diversity

The new dog-sized dino is another example of the incredible diversity found in dinosaur species. Or is it? While, some paleontologists are beginning to see evidence of ethnic dino groups, others are discovering that dinos lived as a homogeneous community.
Written by Boonsri Dickinson, Contributing Editor

It was 2008, during a stroll through Big Bend National Park in Texas that Darren Tanke discovered a dinosaur's skull.

After looking at the dome on the top of its skull, the paleontologists concluded this wee dino probably butted heads with other dinos.

The new species is called Texacephale langstoni and is part of the pachycephalosaur group. The dog-sized dino probably roamed North America 70 to 80 million years ago.

The peach-sized dome acted like a football helmet, so its skull could absorb the impact during combat. However, all this head smashing did leave some damage. The scientists found evidence of unusual holes in its skull.

Discovery News reported that the dino probably smashed heads to fight for the female or for territorial reasons.

More importantly, the paleotologists believe the dinosaurs in North America are different than the dinos found in the south. Each new dino found in Texas reveals that dinosaurs tended to stay put in closed communities. Livescience reported:

"Instead of roaming across the North American continent, we see pockets of different dinosaurs that are pretty isolated from one another," [Nicholas Longrich at Yale University] said. "Every time we get good fossils from Texas, they end up looking very different from those to the north."

However, another study in the Proceedings of the National Academy of Sciences, suggested that dinos roamed all over North America in herds. Researchers at McGill University concluded that the dinos scattered around North America were actually from the same community of dinosaurs. McGill Professor Hans Larsson said in a statement:

"What is exciting about this result is that now we can begin to ask many more questions about how such a large homogeneous community of dinosaurs lived. Did they migrate, or have adequate amounts of gene flow between regional populations, or a mixture of both? How did this widespread dinosaur megafaunal community affect other animals and plants on the regional and continental scale? We're just beginning to scratch the surface of dinosaur ecology."

And here's more evidence that dinosaurs liked roaming: The Times recently reported a "Wee Rex" found in Australia, which challenged current theories on how dinosaurs evolved. While T. Rex is primarily found in the Northern Hemisphere, finding one in the land Down Under made it clear that dinosaurs made their way around the globe.

Credit: Nicholas Longrich

This post was originally published on Smartplanet.com

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