Family helps unearth marine fossil

Associated Press | Posted: Tuesday, August 2, 2011

Associated Press

Preparing the skull, Patrick Druckenmiller works carefully to prepare the plesiosaur skull for its plaster jacket in this photo released by the U.S. Fish and Wildlife Service.

GREAT FALLS — Sleeping on dinosaur sheets and taping up dinosaur posters in his room, Kellen Bradt dreamed he'd be a paleontologist when he grew up.

But Kellen didn't have to wait that long.

On his eighth birthday, he and brother Garrison, 10, their parents David and Jolene and grandpa Bill were part of a paleontological mission that unearthed a 70-million-year-old, 18-foot-long elasmosaur in the C.M. Russell National Wildlife Refuge.

"Both of them loved it," David Bradt said. "It was pretty neat. We did just about everything. The main jobs were diverting the creek and digging through the mud looking for parts."

The Florence rancher spotted the ancient marine reptile's vertebrae while he was bow-hunting elk last fall.

Refuge staff kept secret the remote location about 50 miles south of Malta until a team could return this month to excavate the sea monster.

The fossil was discovered in Bearpaw Shale, which was once mud on the bottom of an ancient 1,000-mile-wide sea that stretched from the Arctic to the Gulf of Mexico when dinosaurs walked the land. Two types of marine reptiles lived in the sea, mosasaurs and plesiosaurs.

Ken Olson of Lewistown, who said he has been involved on four excavations of prehistoric marine reptiles, reviewed Bradt's pictures of his find last fall. A research associate in paleontology for the Museum of the Rockies, Olson figured the "prehistoric sea monster" was a plesiosaur.

Much like the modern-day whale, plesiosaurs breathed air. The aquatic reptiles swam through the sea with four paddlelike flippers, catching fish and other prey with razor-toothed jaws.

The long-necked plesiosaurs, called elasmosaurs, had small skulls and necks with 70 or more neck vertebrae, more than any other known creature.

Photos at first suggested Bradt's find was a short-neck plesiosaur, but the dig revealed it was an elasmosaur.

An elasmosaur could reach lengths of up to 40 feet. This one was only 18 feet, meaning it was either a juvenile or a previously undiscovered species.

Bradt said most of the skull was left encased in rock for its own protection, but he was able to see three teeth before the plaster went on.

"They're about the size of a cougar tooth," he said.

Olson also knew just the person to lead the expedition to recover the fossil, Pat Druckenmiller, one of the world's marine reptile experts and a Montana State University graduate who studied under famed paleontologist Jack Horner.

Druckenmiller, who also is excavating plesiosaurs from the Norwegian island of Svalbard, north of the Arctic Circle, warned the group how long the creature's neck could be and therefore how deeply into the hillside they could have to dig.

He told them few excavations manage to produce both the skull and the rest of the skeleton together because the joint between the neck and head is the weakest of any.

As they dug in a narrow gulch under a blazing sun, the team joked that maybe their plesiosaur cooperated by curling into a ball before dying.

On day two, the diggers found that the plesiosaur's tail was, in fact, wrapped around its body. That meant most of the fossil could be removed in two big chunks of rocks called concretions. Once the specimen is in the lab, diluted acid will dissolve the rock, leaving the bone unharmed.

The crew dragged the heavy sections up a hill on a tarp for a National Guard helicopter to pick up.

On day three, the team followed the curve of the neck bones.

"A better configuration could not have been asked for, not only to minimize work, but also to minimize impacts on the creek," refuge wildlife specialist Beverly Skinner said. She organized the dig, filled out the paperwork and arranged transport of the fossils.

Because of the spine's curve, the 6 feet of hillside removed was sufficient — instead of the 20 feet or more they may have needed to remove if the fossil stretched straight into the hill.

The ultimate prize would be the skull, if they could find it. But a lot can happen in 70 million years, said Bill Berg, deputy project leader at the 1.1-million-acre refuge.

Following a string of more than a dozen neck vertebrae through layers of shale led to the skull, upside-down and showing its teeth.

"The neat thing about this one is the majority of the specimen was right there, the head, neck and most of the body," Berg said. "It's not too often you find intact specimens. The pieces get scattered."

Some pieces of the neck Bradt found last fall washed away in the recent high water and defied a search.

Laws prohibit anyone but the state-specified curator, which in Montana is the Museum of the Rockies, from removing fossils from federal or state land. Berg said work like the excavation is generally up to professional paleontologists from the museum in Bozeman, with occasional invitations for public involvement on outdoor education events.

"This was unique with the dad finding it and showing a keen interest from the beginning," he said. "We wanted to keep them involved because without them, we wouldn't have found it in the first place."

Druckenmiller also brought his wife, Lisa, and 9-year-old daughter, Maggie, for the duration of the excavation.

After approaching the location by boat, the group trekked more than a mile and a half each way through knee-deep mud, swarms of deerflies and chest-high sweet clover — while carrying hand tools and four 50-pound bags of plaster to the site of the find.

U.S. Fish and Wildlife Service staff, among them Paul Pallas, Marcus Hockett, Erin Clark, Dan Harrell, and Jessica Larson, also helped with the excavation.

The fossils will be sent to the University of Alaska in Fairbanks, where Druckenmiller will extract the bones from the rock in which it is imbedded, a process that could take more than a year.

"It's really meticulous work, and it takes a while to do it right," Berg said. "Over the next year or two he'll get it to the point it can be put back together and displayed in Montana."

What Druckenmiller learns from the process will depend on what the creature actually was.

"The two paleontologists we had on site are thinking it's a different species than what we first thought it was, but the final determination will be done when we get further," Berg said.

"It could be a difference species of plesiosaur earlier in the evolutionary process, one they hadn't seen before. But the identification has changed twice since it was found, and it could change again."

Many of the best fossil specimens in the world have been found in north-central Montana's badlands. However, diggers usually discover land animals there, such as duckbills, triceratops and Tyrannosaurus rex.

Berg said the specimen doesn't have a nickname like the famous T-rex "Sue."

"That may be a naming contest we could initiate," he said. "I haven't even heard anyone infer there's a nickname."