Paleontologists have unearthed a nearly complete fossil of a dimetrodon, a reptile-like predator that roamed the Permian landscape 287 million years ago.

This weekend, the team is working to transport the 400-pound animal's torso from its resting place in north Texas to Houston, where the fossil will be prepped for display in the newly renovated Houston Museum of Natural Science (HMNS) paleontology hall in 2012.

Famous for the enormous fin on its back, dimetrodon is often mistaken for a dinosaur, although dimetrodons pre-dated dinos by millions of years. The creature could easily pass as a reptile, but dimetrodon wasn't precisely reptilian, either: It was a synapsid, a category that includes modern mammals. Think of dimetrodon as a very distant, very toothy cousin.

The first dimetrodon fossils were discovered in the late 1800s, but the new find is the most complete skeleton of the species found in 100 years, said Robert Bakker, HMNS curator of paleontology and the director of the dig that uncovered the fossil.

"It's stunning," Bakker told LiveScience. "Everyone who visits it, and there's been a steady stream of ranchers and amateur paleontologists, they just sit at the edge of the quarry and stare in reverence."

The dimetrodon, dubbed "Wet Willi" by the researchers after Samuel Williston, a paleontologist who dug at the site 100 years ago, was found in north-central Texas in the remains of an ancient sinkhole. The site has been a rich source of dimetrodon bones for decades, but the Houston team began the first meticulous exploration of the area five years ago. Since then, the researchers have turned up a number of partial dimetrodon fossils as well as the bones of smaller reptiles and amphibians.

"This site has more dimetrodon bones in it than the rest of the world put together," Bakker said.

Wet Wilii

But until this year, the researchers and their teams of volunteers hadn't turned up anything as complete as Willi. The fossil was first discovered on a steamy day in June. David Temple, the associate curator of paleontology at the Houston museum, was digging a drainage ditch in the fossil site when he came across the dimetrodon's jaw, full of steak-knife teeth.