Area’s fertile ground has recently yielded important relics from the dinosaur age

By Rachael Scarborough King / The Bulletin
Published: April 22. 2007 5:00AM PST

MITCHELL – Digging her toes into the steep, slippery side of a sagebrush- and wildflower-covered hill, Ellen Morris Bishop peered at a stream of loose rocks.

Picking up a yellowish, dictionary-sized rock, she displayed the streaky imprint of a 40-million-year-old plant.

“Now here we have a fossil that you can actually see,” Bishop said, identifying it as a relative of the horsetail rush. “Isn’t that cool? If you’re looking for fossils, you don’t have to show up and start hammering away at things – if you just spend some time looking at the outcrops, you can find things like this.”

Bishop, a geologist and director of the Oregon Paleo Lands Institute in Fossil, said the spot northwest of Mitchell along the banks of Cherry Creek in Jefferson County is a former marshland that now has many plant fossils.

A few miles away, where red-brown cliffs surge from the John Day River, the area’s transition over hundreds of millions of years from a marine environment to a tropical volcanic zone to today’s desert is perceptible in the landscape’s colored stripes of rocks. For scientists and amateur paleontologists, that diverse geologic history makes Central and Eastern Oregon an important site, where the most recent major find was a Jurassic-age crocodile in eastern Crook County.

Andrew Bland was visiting the county in late 2005 with the North America Research Group, a fossil enthusiasts’ group based in Beaverton, when he noticed some bone fragments poking out of the ground.

“We knew that other marine vertebrate fossils had been found in that area, so it’s something we keep an eye open (for) but never expect to find,” said Bland, who was the first to spot the Jurassic crocodile while looking for marine mollusks called ammonites.

“Initially I was excited that I had found some bone material … and luckily only a few feet up from where I found the initial material I saw some more bone sticking out.”

Bland is an amateur paleontologist who usually takes a trip a month with his group to look for fossils.

“It’s not like I imagined as a kid when you find fossils that you, like, split a rock open and there it is,” Bland said. “Over the next six months, I spent probably over 100 hours working under a microscope chipping away at the limestone to expose all the bone material.” From the rocky formations of Central Oregon’s High Desert, paleontologists, archaeologists and amateur fossil hunters have dug up prehistoric creatures like Bland’s Jurassic crocodile, a plesiosaur – a 25-foot-long marine reptile – and a pterosaur, a flying reptile with a 15-foot wingspan.

Amateur fossil collectors have made many of the most significant finds, which Bishop called “the coolest part about the plesiosaur and the crocodile.”

“Collecting fossils is a very Zen thing … you train your eye and you stay in a place for a very long time and, gradually, you begin to see little differences in the rocks,” she said. “If you find something that’s going to be a contribution to the knowledge of mankind, I think it’s part of your responsibility to help people understand what it is.”

The geology of the High Desert

The bands of volcanoes that blanketed Central Oregon with ash and lava between 40 and 50 million years ago left behind a rich swath of fossilized plant and animal remains, local scientists said.

“If you had to design something to preserve a fossil, there’s nothing better than volcanic ash – it’s like those Styrofoam popcorn things, it’s the perfect packing,” said William Orr, a retired geologist and director of the Thomas Condon State Museum of Fossils at the University of Oregon. “So the reason our fossil record is so good is because the volcanic record is complete.”

Many of the lava vents from those now-eroded volcanoes cooled into the jagged cliffs in areas of Jefferson and Wheeler counties. Orr described Central and Eastern Oregon – where the John Day Fossil Beds National Monument is located – as “real dinosaur country, but they haven’t found dinosaurs yet.”

Some bones from a pterosaur were found in Crook County in the late 1800s, Orr said. Like the pterosaur, he added, the plesiosaur and Jurassic crocodile date from the age of dinosaurs, which lasted from 250 million years ago to 65 million years ago.

Although the crocodile skeleton was discovered in 2005, the University of Oregon didn’t announce the find until last month.

“It’s not a dinosaur, but it coexisted within the water when the dinosaurs were bopping around on land,” he said, adding that only one possible dinosaur skeleton has been found in Oregon. “I always thought in my heart, well, they’re here, we just haven’t looked for them.”

And while Central and Eastern Oregon have not produced a dinosaur, Bishop said, “we do have dinosaur relatives – we have lots of fearsome and toothed creatures that lived mostly in the seas.”

Piecing together the puzzle

Even before the volcanoes, in the Cretaceous Era 100 million years ago, much of the state of Oregon was under water. Meat-eating reptiles such as plesiosaurs, which may have looked a lot like the mythical Loch Ness monster, roamed the ocean.

Today, fossils like the plesiosaur and Jurassic crocodile discovered in the Crook County area in 2004 and 2005, respectively, help scientists paint a picture of what life was like hundreds of millions of years ago, said John Zancanella, a geologist and the paleontology program coordinator for the Bureau of Land Management in Oregon and Washington.

In both cases, hobbyists looking for fossilized sea shells found the bones and enlisted trained scientists to help with the analysis, Zancanella said. When amateur paleontologists, Mike Kelly and Greg Kovalchuk, found the remnants of the plesiosaur near Prineville in 2004, they contacted Zancanella.

“We find plesiosaurs in other parts of the country, but this was the first one found in the Northwest, so what it does is it adds another piece of the puzzle to our understanding of ancient times and ancient environments,” said Zancanella, who works in the BLM’s Prineville office. “The context is one of the most important things about any fossil that you find.”

The plesiosaur Kelly and Kovalchuk uncovered probably lived about 90 to 100 million years ago, and scientists think it had an alligator-like head with sharp teeth that it used to eat mostly fish.

The fossil, which included the teeth and 3-foot-long lower jaw of the animal, is now housed at the South Dakota Museum of Geo-logy.

“It had been 85 years since anyone had actually found a vertebrate specimen from this rock type,” Zancanella said. “So I was pretty excited about the find and very excited about the two individuals, who showed a lot of restraint and ethics and character to not rip this thing out of the ground.”

Unlike the plesiosaur, the thalattosuchia – or Jurassic-age crocodile – found in eastern Crook County in 2005 was not a native Oregonian.

The reptile probably lived in the tropical seas near south China about 150 to 180 million years ago, Orr said, and was about 6 to 8 feet long. It had a long, fishlike tail and needle teeth for eating fish and squid. When it died it became fossilized in the ocean floor and then drifted to North America through a process known as continental shift or plate tectonics.

“The stuff from, let’s say, 30 million years ago – that’s the John Day formation – that’s all local, that’s homegrown, but the older stuff … was all produced somewhere else and imported here and stuck on,” Orr said. “Crook County has this great diversity of fossils because some of it came from as far away as China.”

A Jurassic crocodile is also an important find because crocodiles’ basic physiological structure has not changed drastically even over such a long time period, Orr said. He is currently analyzing the fossil, which will be sent to the University of Iowa for further research and eventually displayed at the Rice Northwest Museum of Rocks and Minerals in Hillsboro.

“If we ever get to the bottom of what knocked off the dinosaurs, it will not be looking at dinosaurs because the dinosaurs were what I call the losers – it will be through looking at crocodiles or turtles,” he said. “One of those two creatures has the answer to one of the biggest crises in the history of life.”

‘An addictive hobby’

While the dramatic geology of Crook County and surrounding areas has led to some important finds for scientific research, it also offers smaller scale thrills for the amateur fossil hunter.

“I was probably interested in dinosaurs as a kid, but I really didn’t realize that even though Oregon doesn’t have dinosaurs, there’s some very exciting things that could be found by everyone,” said Bland, who found the Jurassic crocodile bones. “You could probably find a fossil in every county of Oregon, and for me as a kid that would have been great to have that information.”

He said that the four-year-old North America Research Group has about 60 members who take monthly trips to look for fossils in different parts of Oregon and Washington. A software quality engineer from Vancouver, Wash., Bland said fossil hunting is “just an addictive hobby I’ve picked up.”

Because Bland and the other members of the group found the bones on private property, they were able to remove them with the permission of the owner. He then worked with Orr, at the University of Oregon, and other scientists to identify the creature.

Usually, when the group goes fossil hunting, Bland said, they look for previously unknown species of invertebrates that may have scientific value. He described the crocodile as the most “sexy” fossil the group has found so far, but added that they have donated many others to Hillsboro’s Rice Museum.

“Most of Oregon throughout history, up until the end of the Cretaceous, was a marine environment and in a marine environment you get a lot of sedimentation, and that’s primarily where you find fossils,” he said. “In Central Oregon because it’s high desert, there’s a lot of exposure. You’re more apt to find fossils there than, say, in the Willamette Valley where you have a lot of vegetation and overgrowth.”

But, he added, people often “spend a lot of time looking and finding nothing.” He doesn’t have a particular method for finding fossils, other than reading up beforehand on the area’s geology and then trying to scout the ground as thoroughly as possible.

“If you’re in an area that’s fossiliferous, you usually either find them or you don’t,” he said. “They’re usually obvious, or you’re not finding anything.”

Judy Elkins, the owner of Elkins Gem Stones in Prineville, said she often directs tourists to interesting fossil areas in Crook County.

“People have a much better chance of finding something if they know what they’re looking for,” Elkins said.

Zancanella, of the BLM, said collecting fossils on private land is legal, as long as the owner is aware. On federal lands there are limits on the amount of invertebrate and botanical fossils people can collect, and removing vertebrates is not allowed.

“When you think about life on Earth generally, the invertebrates and the plants make up the bulk of life, so those fossils tend to be more common, and the vertebrates make up a very small percentage of life on Earth, so they tend to be more rare,” he said.

Educational tourism

In the aptly named town of Fossil, about two hours northeast of Prineville, the two-year-old Oregon Paleo Lands Institute is working to expose tourists and locals alike to Central Oregon’s unique geology.

Bishop, the institute’s director, described its mission as “educational tourism.” Programs often combine artistic activities with outdoor trips to learn about the environment.

“The idea is basically to connect people with the landscape, sort of past, present and future, and think about our impact on these landscapes and understand how to become stewards,” she said.

She added that the layers of rocks in Central and Eastern Oregon can help geologists understand more about past cycles of climate change and extinction.

“To me, the lessons of the past are something that, just like in human history we need to look back at the lessons we learned in the past and apply those to today. We also need to take the lessons we learned from past ecosystems and apply those to today,” she said.

Sites like the Painted Hills in Wheeler County demonstrate the changing environment, Bishop said, as the bands of tropical red soil merge into yellow dirt that demonstrates a more temperate climate.

Zancanella agreed that the area’s rock formations are important for climate change scientists.

“This is one of the few places in the world where you can get rocks that represent 40 million years of continuous sequence exposed in the same place,” he said.

That unique geology benefits both scientists and amateurs. Judy Elkins, whose father opened Prineville’s Elkins Gem Stones in 1958, said she doesn’t find much time for rock hunting anymore, but still has exciting moments.

“It’s a real thrill to find a leaf (fossil) – I was up there one time with some friends, and we pulled a piece of rock off and it opened up and there it was,” she said. “My friend says, ‘Oh, the last time this leaf was in the sunlight was 40 million years ago,’ and it kind of hit me right then how remarkable it was. That was kind of a moment of revelation for me, despite having been in this business since I was a small child.”

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to Top