Montana/Dakotas

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Fossilized Remains of Giant Sea Predator Found in the Breaks

 story and photos by
Craig Flentie
Central Montana District

 Ray Rogers at fossil site

It did not take long for Ray Rogers to identify the fossils as those of a plesiosaur.

Jacob Greenwood at fossil site
Jacob Greenwood begins piecing together fossilized bones at the discovery site.

It was another hot, still day in the Missouri Breaks--the kind of July day that makes the cattle and wild things lay-up in the shade and wait for the cool of evening before moving about much. About the only things moving across the landscape during the heat of this day was a rolling blanket of grasshoppers and two BLMers.

Jacob Greenwood and Katelyn Miller (summer seasonals on the Lewistown Field Office range staff) had parked their BLM pickup and hiked about a half mile into a remote coulee to complete a regularly scheduled monitoring/condition check on a BLM livestock reservoir.

Aside from a little saline seep above the reservoir and slightly brackish water (both fairly common conditions in this country this time of year) the reservoir was in good shape.  On their way out, Greenwood and Miller changed their route and walked north through a different coulee to reach the ridge that would take them back toward the vehicle.

They had nearly reached the ridge top when they noticed a cluster of rock-like objects exposed on an open, shale hillside that looked somehow out of place. Closer examination revealed a cluster of fossilized bones--some about the size of a lemon, others as large as a grapefruit. Some of the pieces were clearly identifiable as portions of a ball joint, vertebras, and a variety of other bone segments.    

Neither Greenwood nor Miller was entirely sure what they had found. However, they both recognized it was a unique moment as they were looking at a particular set of fossil remains (65 million years old or older) that in all probability no human had previously seen. 

Jacob and Katelyn took a GPS reading to mark the location and collected some of the larger, exposed pieces.

Back in Lewistown, Greenwood and Miller reported the find and gave the collected pieces to Zane Fulbright, an archaeologist in the Lewistown Field Office. While paleontology is not exactly Fulbright’s forte, Zane has a long list of professional contacts and knew where to turn for answers.

Team Rogers

Zane contacted Ray and Kristi Rogers, who happened to be in Lewistown this summer, about viewing the collected pieces and possibly helping with a site visit to identify the creature Jacob and Katelyn found.

Ray and Kristi are somewhat unique characters to find kickin’ around a coffee shop in Lewistown, Mont.

Ray Rogers holds a Ph.D. in geology from the University of Montana and is a professor and chair of the geology department at Macalester College in Saint Paul, Minn. Kristi Rogers holds a Ph.D. in biology and is an assistant professor of biology and geology at Macalester College.

They are well known in the scientific community for their paleontological research and have worked in seemingly exotic sites scattered from Antarctica to Madagascar. Ray is currently on a one-year sabbatical from Macalester College. Ray and Kristi recently purchased a house in Lewistown because of its proximity to the Missouri Breaks, an area they feel is a treasure trove of fossilized information about micro-invertebrates and other life forms of prehistoric days.

Their passion for paleontological research first brought them to Montana in the early 1990s and they have made it a point to return every summer since then to continue their quest. Their drive is not to find museum display pieces, but to continue searching for answers to the web of questions that connect prehistoric life to present life. 

The Rogers’ research is designed to answer questions about how a particular set of fossils formed in a certain set of rocks; whether the fossilized creature was from the local area or was moved here by water, glacier or time; whether or not dinosaurs migrated across the Breaks; how do previous extinctions relate to today’s increased stress and climate change; and is the rate of extinction increasing?

Answering these connecting questions in the fossil record can help mankind understand where life has been and perhaps where life is going.    

Ray and Kristi conduct their research under the administrative umbrella of a permit agreement between the BLM and Macalester College. They bring undergraduate geology students to the Missouri River Breaks every year for field school opportunities and many of them have published papers based on their research in the Breaks. In 2010, the BLM formalized this relationship by establishing a Challenge Cost Share agreement with Macalester College with the goal of developing interpretive and educational material for Monument visitors and staff.

Late in August, Ray and Kristi had a chance to examine the collected fossils in the Lewistown Field Office. Then Ray accompanied Zane, Jacob, and Katelyn back to the site to confirm the identity of the creature buried in this remote coulee in the Breaks.

The ride to the site took much longer than the identification process. After excavating a few buried fossils and vacuuming the surface for additional remains, Ray quickly identified the fossilized remains as those of a plesiosaur, similar to the find recently excavated on the Charles M. Russell National Wildlife Refuge.

Plesiosaur

The fossil record has yielded enough information to help scientists piece together a pretty good understanding of the plesiosaur.

The plesiosaur family occupied the top of the water-based food chain in the seas that covered much of the world and Montana 300 – 150 million years ago.

If other creatures of the prehistoric day could reason, they recognized the plesiosaur as sea dwelling predator that cast a long shadow of fear wherever it swam.

A plesiosaur could grow to over 50 feet long and weigh over 12 tons. It had a long slender neck, a relatively small head, teeth and jaws designed for killing, and four fins on the lower side of its bulky body to propel itself. 

They were opportunistic hunters/killers that killed with brute force; finesse was not in their tool box. Scientists believe a plesiosaur would bite into a victim of the moment with a powerfully built jaw, then thrash about until they started tearing chucks off of their unfortunate victim. Their hunting/feeding technique has been deemed a real blood bath that could make a T. rex feel queasy.

Significance of this Find   

This particular find probably is not complete enough to be of museum display quality, but that’s not the emphasis of this field of research.

Ray Rogers has since contacted several of his scientific peers and they all agree that this find has the potential to provide information that could help unravel the web of questions surrounding the link between prehistoric life and present life. The remains definitely have value for educational purposes and countertop displays for public enjoyment.

Time will tell what this find may provide. It appears that next field season Team Rogers, several of their peers and students and perhaps a graduate student or two from the University of Alaska-Fairbanks will be trekking back into this lonely ridge to excavate the remains of this plesiosaur.

Research, discovery, and learning are often very structured processes, but on occasion they’re as random as taking a different route back to the truck.