WORLAND, Wyo. — For the past couple weeks, people have been seen doing something strange on the edge of the Big Horn River in Worland’s Riverside Rotary Park.
Those people are a crew of graduate and post doctorate students from the University of Florida, University of Minnesota, Duke University and the Florida Museum of Natural History and what they are doing is washing dirt taken from an area east of Worland in search of small animal fossils.
The crew is led by Johnathan Bloch, a researcher at the Florida Museum of Natural History, who has been coming to Worland for over 20 years in search of fossils.
Crew members Natasha Vitek and Paul Morse explained that the dirt that they are washing comes from the badlands about 10 miles east of Worland, about half way between Worland and Ten Sleep on BLM (Bureau of Land Management) lands. The dirt is about 56 million years old and contains small animal fossils that are important in learning what was going on at that time.
“The environment was going crazy back then, all kinds of things were happening,” Vitek said. “The climate was changing, the plants were changing and so we are trying to figure out what the animals were doing in all of this chaos.”
The badlands in the Big Horn Basin preserves one of the best records in the world of land animals, according to Vitek. That’s what the researchers are searching, and Vitek said they are finding the little stuff is particularly interesting.
“The big medium-sized mammals that would have been yea tall (three foot) in life you can see their bits and pieces on the ground as you are walking around,” she said. “But the little things, the little things that would fit in your hand, mouse-size, shrew-size, even small cat-size, if you’re just walking around the badlands you’re not going to see a little tooth, it’s just too tiny.”
“The only way to really find those animals and really document all of the animals is to find a site that looks promising, put your shovel into the dirt, bag it up and wash it through screens. Once you get rid of the bentonite and clays and stuff what you have left are fossils,” Vitek said.
Based on what researchers know about small animals today, they tend to be more responsive to changes in temperature or seasonality, added Morse. And the team is also interested in documenting what was happening at that time.
Some people are under the assumption that the crew is searching for fossils at the river’s edge, but Morse said that is a common misconception.
“The river is carrying sediment from the entire course of the river,” Morse said. “There could possibly be bones in it but if we were to find them we would have no idea where or when it was from. When we are out there in the badlands we can use those nice colorful soil horizons and get a very accurate estimation of when we’re sampling from. That’s important to us; to try to be as accurate as possible about the timing of these different fossils.”
The crew had been camping at the dig site for about two weeks using only man power and handheld tools to collect the dirt. Morse stated that about half the crew moved on to Bridger Basin while the remaining crew finishes up passing the remaining collected dirt through the screens and will join the team when they are done.
“It takes a big crew as it turns out,” he said. “You need people out there all the time putting shovels in the ground and you need people here all the time passing that dirt through the screens. It’s a big operation.”
Many of the fossils are quite small but once in while the crew discovers a larger small fossil such as the tiny jaw bone they found in June, is an invaluable discovery.
“It sounds very small but what’s incredibly impressive for us would be say a whole half of a lower jaw of an animal and all eight teeth or something like that. We get a lot of information out of something like that and because all these fossils are usually coming out of ancient river deposits and stuff if you think about the animals, like if you are ever walking out in the badlands and you see just like a dead rabbit you don’t normally see like the whole rabbit skeleton laying out. You will see like a little rabbit toe, a little chunk of the skull and it just breaks up more and more the further it’s out. Those are the kinds of remains that we are getting out of these fossil deposits, little bits of and pieces of things. So to have one piece all together like that, that’s the kind of stuff that we are getting out of the screen wash and it’s really incredible for us,” Vitek said.
Vitek explained that the crew takes the fossils that they find back to the Florida Museum of Natural History where the fossils are given a second wash using even finer screens and given to herself, Morse and Bloch in small vials to be identified and cataloged. We sit at microscopes and go through the fossils tooth by tooth and bone by bone, she said.
The whole process could take almost a year.
“Usually we will finish this up right around next June and then we will come back out here and do it again,” Morse said.
Last year, the team moved about 7,000 pound of dirt, and Morse believes they exceed that amount this year. Out of all that dirt, Morse said they typically find about 2,500 fossils.
“It’s tremendously useful information,” he explained. “Many of these animals that we are finding are discussed in the display at the Washakie Museum here in town. They have interviews with a couple of other great paleontologists out here like Kenneth Rose and Scott Wing.”
Information from: Northern Wyoming Daily News, http://www.wyodaily.com