POCATELLO, Idaho — It appears the big one got away in eastern Idaho.

Scientists using CT scans and 3-D virtual reconstructions have determined that fish fossil teeth found in the region, including Utah, don't belong to a giant shark, but instead come from a species more closely related to ratfish.

Leif Tapanila is an Idaho State University associate professor of geosciences and also a research curator with the Idaho Museum of Natural History.

He said scientists determined the teeth fit in the back of the jaw. He said shark teeth would be located in the front of the jaw.

"New CT scans of a unique specimen from Idaho show the spiral of teeth within the jaws of the animal, giving new information on what the animal looked like, how it ate," Tapanila said.

He said the study, "Jaws for a spiral toothwhorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion," is being published by the Royal Society, based in London.

The museum in eastern Idaho has the largest public collection of the fossilized teeth.

Part of the problem in classifying the fish, scientists said, is that it had cartilage for skeletal structure, rather than bone.

But based on 3-D virtual reconstruction of the fish's jaw, scientists can determine other characteristics. As a result, the Idaho Museum of Natural History is creating a 13-foot-long Helicoprion. Experts say the fish likely grew to 25 feet.