Utah Rocks Yield 2 New Species of Dinosaurs : Paleontology: Bones of a vicious killer and a ‘war machine’ may help scientists fill a gap in the evolutionary picture.

On a routine scouting trip for fossil sites in eastern Utah, paleontologist Jim Kirkland stopped for lunch in Moab and wandered into a rock shop. What he saw changed his life, and, perhaps, the direction of dinosaur science.

In a glass case was a 250-pound block of limestone containing fossilized plates from an armored dinosaur, which Kirkland recognized as a potential new species.

“I was bouncing off the walls,” recalled Kirkland, who is employed by a group called the Dinomation International Society that organizes tours of dinosaur fossil sites.

The shop owner showed Kirkland where the fossils were found, at a hillside quarry north of Arches National Park. Now, two years later, quarry diggers are removing piece after fossilized piece of two new species of dinosaurs.

“For a dinosaur researcher, this is about as exciting as discovering a whole new planet,” Kirkland said. “I have a feeling over the next 10 years, we’re going to be finding a lot of new species in there.”

It was here that Kirkland and a co-worker discovered the predator Utahraptor, described as one of the most vicious species of dinosaur yet discovered.

At 22 feet long, Utahraptor is by far the largest of the dromaeosarids, a family of dinosaurs considered to be crucial evidence supporting the theory that dinosaurs were warm-blooded and more closely related to birds than to reptiles.

Utahraptor is thought to be a cousin of deinonychus, a 6-foot-tall predator with a large, slashing claw on each hind foot. Researchers believe deinonychus moved quickly and could pounce on much larger prey, attacking with all four limbs.

The quarry’s other species, yet to be named, is an armored “nodosaur,” 6 to 10 feet long, with body armor, bony plates running down its spine and thorns on its tail.

“This is a real war machine,” said Donald Burge, director of the Prehistoric Museum at the College of Eastern Utah, which is overseeing the dig.

Kirkland and his associates are gushing about the new find, and other paleontologists agree it is significant. But they say it is too early to tell how it fits into the scheme of dinosaur evolution.

“We’re really poking around in a whole new ball game, trying to decide where these animals fit in a large panorama,” said John Ostrom, a Yale University paleontologist. “It will take years and years to sort all that out. . . . It’s something that cannot be rushed.”

The quarry is one of only a handful in the world yielding fossils from the early Cretaceous Period, about 120 million years ago.

“It’s kind of a missing link in knowledge of dinosaurs,” Burge said. “That’s why everything found in the lower Cretaceous is so exciting.”

The Cretaceous, which ended 65 million years ago, was the last age of the dinosaurs. Its later years included species like Tyrannosaurus rex and Triceratops.

Amateur rockhound Robert Gaston discovered the quarry three years ago, on an October day when he was out “hunting bones” in the rocky high desert country northwest of Moab. At the bottom of a small butte, he spotted fossils in a piece of rock that had broken free and rolled down the hill.

The rock contained fossilized “scutes,” small armored plates the size of an almond. Gaston worked up the hill until he found an exposed edge of limestone that contained more armored plates.

“I knew when I found the plate with the scutes that it was important,” he said. “I didn’t realize it would be this important.”

Gaston, a furniture-maker from Albuquerque, N.M., returned to the quarry for several days this summer, joining other volunteers in the meticulous process of removing multimillion-year-old remains from solid rock.

On one recent day, as the sun climbed in the sky, Gaston hunched over a fossil-filled shelf of limestone, using dental tools and liquid plastic to prepare the fossils for removal. By the end of the day, he had taken out a nodosaur rib and a 5-centimeter tooth from Utahraptor.

The fossils are being taken to the College of Eastern Utah museum in Price, where they are stored, studied and displayed. Already on display are a nine-inch claw core bone and finger bone from Utahraptor, and armored plates and a shoulder blade from the nodosaur.

Since mid-August, workers have taken at least 60 bones from the quarry, bringing to 200 the number found since 1990.

“Usually when you start a dinosaur dig, your expectations are that you’re only going to find a few bones, maybe only one bone,” Burge said. “Anytime you find more than 200 bones, that’s great. There’s no end in sight, really. Hopefully there are hundreds more.”