Fossils of seagoing dinosaur show creatures roamed area 93 million years ago

By Kerry Fehr-Snyder

July 28, 2000

PHOENIX, Arizona (The Arizona Republic Online) -- Paleontologists in northern Arizona are beginning to analyze a rare find, the skeletal remains of two giant Loch Ness monsterlike creatures that lived 93 million years ago.

Two teenagers found the fossil remains of the seagoing dinosaurs, called plesiosaurs, last year in the Glen Canyon National Recreational Area near Lake Powell. The reptilian skeletons, which include teeth, vertebrae, skulls, ribs and jawbones, are among the most complete ever to end up in the Museum of Northern Arizona in Flagstaff.

"To find one intact is really rare," said Barry Albright, the museum's curator of geology and paleontology. "That's why this is such a blast."

Because of the way marine creatures die and decay, Albright said, paleontologists typically find a little bone, dig back and there's nothing else there. Or they find the bones from the neck or pieces of a skull, if they're lucky.

But in this case, those excavating the site were able to find virtually every part of the two specimens.

"This is what we live for," Albright said.

Although a thorough analysis of the specimens has only just begun, Albright and the other researchers believe they may have found a new genus of plesiosaur, based on the type of creatures the two dinosaurs ate.

Alan Titus, a paleontologist at the nearby Grand Staircase-Escalante National Monument, determined that the specimens, which fed on fish and sharks, were found near ammonites, extinct squidlike creatures that lived 93 million years ago. That makes the two plesiosaurs potentially older than most found in North America. Up until recently, most plesiosaurs were found in Kansas, Nebraska and South Dakota.

"It shouldn't be unusual, but a complete find is rare," said Mike Everhart, a biologist who maintains a Web site about dinosaurs called oceansofkansas.com. "This is more evidence for the variety of life that existed in the seaway at the time."

Everhart, who wasn't familiar with the Lake Powell find, said he was surprised to learn that two nearly complete plesiosaurs were found so close to each other.

"It would be unusual for both of them to die at the same time. They must have been stranded together or subject to some catastrophic event," he said.

The Lake Powell find is consistent with the geological view that during the Cretaceous Period, which ended 65 million years ago, a huge seaway cut in half what is now considered North America. This intercontinental seaway, which was at its widest point 93 million years ago, was inhabited by two types of plesiosaurs: one of which had a long neck and a small head and another called a pliosaur, with a short neck and big head. Both types are commonly referred to as plesiosaurs.

Based on the Lake Powell fossil measurements - the skulls were at least 6 feet long, and the bodies were at least 25 feet in length - the two appear to be pliosaurs.

The fossils initially were spotted by two teenagers from southern Utah who were hiking in the area. David Rankin, now 15, was fossil hunting with his friend, Wryht Short, when he saw a piece of bone sticking out from a hillside.

"I yelled out to 'Wryhty' as soon as I saw it," Rankin said. "I have my eye tuned to finding bone." That said, Rankin admits he got lucky. "I knew it was something big, but I didn't want to dig it up," he said.

Instead, the boys carefully gathered the exposed bones and quickly contacted their friend and mentor, Merle Graffam. A commercial artist turned amateur paleontologist, Graffam believed the bones might be prehistoric and contacted David Gillette, Colbert curator of geology and paleontology at the Museum of Northern Arizona in Flagstaff.

Gillette visited the sites and determined that yes, indeed, the bones should be excavated. But because the fossils were found on property managed by the National Park Service, Gillette and his colleagues had to apply for a special permit to excavate the find from the Glen Canyon National Recreation Area.

Two weeks ago, a crew including Rankin, Graffam and other members of the public participating in the museum's Ventures Program, went to the sites and removed the remains. Excluding Rankin and Graffam was not an option.

"It's the least we could do," said the museum's Albright. "They found the fossils, so of course, we included them in the dig.

"They sweated every much as the rest of us."

For Rankin, it was not the first time he's been on a dig. A self-described desert rat who began fossil hunting when he was 8 in the small rural town of Big Water, Utah, he's participated on seven digs in the past 18 months.

"I have a really good eye," he said. "Every time I go out, I find stuff."

But his latest find, more than the others, solidified Rankin's interest in paleontology.

"I've been thinking about it seriously," he said. "I've been doing all the right schooling and am taking correspondence classes so I can graduate a year early.

"It's just really, really cool."