"One [find] is unusual, eight is outstanding," said Scott Foss, regional paleontologist with the Bureau of Land Management, of the newest creature featured in a paper published Wednesday in the online journal PLoS ONE.
The upper jaw bone of the meat-eating creature, small enough to fit in the palm of the hand, was discovered in 2004 in a formation in the Crystal Geyser area near Green River, where it lived 125 million years ago. It is the oldest species found in North America belonging to the "raptor-like" troodon group of dinosaurs.
Foss said worldwide there about 700 named dinosaurs.
"This string of dinosaur descriptions means that a full one percent of all known dinosaur species were described from lands in Utah during 2010," said Foss. "That's what's interesting and fun about this."
Seven of the new species were found on BLM land and one in Dinosaur National Monument.
State paleontologist Jim Kirkland, who co-authored the paper and was at the site when the discovery was made, said the jawbone is hollow and could be inflated "like a balloon."
Kirkland said he is unaware of such a characteristic in other fossilized dinosaurs and can only speculate on its purpose.
"There's no clue what it was used for," he said. "Maybe it was some kind of resonating chamber for vocalization."
He said some birds have resonance capabilities using air for calling to other birds.
He believes the jaw bone belonged to a lightweight creature about 6 to 7 feet long.
"There's no question it would have been feathered," he said.
The unique fossil was discovered by Celina and Marina Suarez, twin sisters from Temple University who were investigating the site with Kirkland and the Utah Geological Survey while working on their master's degrees in geology.
"We were just following a geologic layer when we saw these bones sticking out of a hillside and reported it to the [UGS] crew," said Celina Suarez on Wednesday.
She said the site is rich in fossilized bones, and it took staff and students at the College of Eastern Utah in Price to help excavate the area and describe what was found at the dig.
She said she and her sister were surprised when Kirkland suggested naming the creature after them. The dinosaur's name translates to: "Twin Predatory Thief of the Suarezes."
"I told [Kirkland] I thought he was joking at first," said Celina Suarez. "But he said he was serious. It's pretty cool."
Kirkland said the abundance of species discovered in Utah makes it the richest dinosaur bone yard in the country and second in the world only to China.
Utah's isolated rugged areas and searing summer climate kept the rich bone deposits from discovery for many years, Kirkland said. Paleontologist were more inclined to search for fossils in the cooler climes of Montana and Canada.
Utah's paleo-profile got big boost in notoriety beginning in the 1990s when Bill Clinton used the Antiquities Act to create the Grand Staircase-Escalante National Monument, which has since produced a steady stream of new fossils. It also made the area eligible for federal funds for research.
Kirkland said the fossils from some sites were used as the "antiquities" required for Clinton to use the Antiquities Act.
Kirkland praises China for spending large amounts on paleontology research and museums.
In the past decade, he said China has spent a billion dollars on paleontology.
"That's more than has been spent in the history of paleontology by the world," he joked. "They build museums there as fast as they build power plants."
He said world interest in all things dinosaur can be a money-maker for Utah, where visitors would be inclined to stop at museums and stay in motels.
"It brings money to Utah," Kirkland said. "Good clean tourist money."