“I was flown to Vancouver to present my research at the annual meeting of the Geological Society of America.” — Patrick Sullivan

BY | Patrick Sullivan ’16
Shoreview, Minn.

Photos by Jeff Thole

I study the origin and taphonomy of Late Cretaceous vertebrate microfossils collected from Montana bonebeds with my research mentor, Professor Raymond Rogers. Taphonomy is halfway between geology and paleontology; taphonomists study how animals decay over time and how their bones are preserved in the fossil record.

When people think about paleontology, they generally think of Jurassic Park with rugged, dusty researchers revealing perfectly articulated dinosaur skeletons. In my case, the majority of the bones we discover are no bigger than a small ant. We consider a microscopic frog jaw to be just as important as a large dinosaur bone because we are trying to reconstruct the paleoenvironment (or ancient environment) of a 75-million-year-old Cretaceous swamp, and every bone gives us insight into what was living there and in what abundance.

My collection tools include a microscope, a paintbrush, and a cardboard tray. The sediment is sieved using a machine invented by Macalester’s genius resident mechanic, Ken Moffett. After a couple hours of repeated dunking in buckets of water, the soil turns to mud and dissolves, leaving only clam shell and bone. Research assistants then pick out the bones from the shell and sediment using a tiny, wetted paintbrush under a microscope and sort the fossils into identifiable and unidentifiable bins.

Amphibian skeletons, dinosaur and crocodilian teeth, fish scales and vertebrae, dinosaur eggshell, and turtle carapace are some of the elements that we pick out every day in the lab. The majority of fossils found are tiny fragments, but these can tell us about the conditions in which these bones were buried.

For the last year, I have been working on characterizing the feeding ecology in these microfossil accumulations. A small fraction of the bones have feeding traces like tooth marks and digestion traces that could tell us about who was eating whom in this swamp. Last semester, Ray and I contacted a professor at the University of Florida who has access to captive alligators and asked him to conduct a feeding experiment on fish scale digestion in alligators. I’m very excited to receive the gut and fecal samples to see if they show similarities with the presumably digested remnants that we are recovering from these ancient swamps.

Sometimes I have to step back and realize how cool this all is. I have gone to a beautiful area—the Upper Missouri River Breaks National Monument in central Montana—every summer to collect these amazing deposits. Last fall, I was flown to Vancouver to present my research at the annual meeting of the Geological Society of America.

At Macalester, if a student is interested in a professor’s research, it isn’t very hard to end up working in that research lab. In my case, I just spent a lot of my free time in my second semester at Mac picking fossils in Ray’s lab. By summer, I was a lab employee and got to go to Montana with Ray and the other research students. Now I am a lab manager working on independent research.

To prospective students thinking about pursuing any science at Macalester: These opportunities won’t present themselves until you do, so if you hear about a lab doing something cool, talk to the professor.

Sullivan’s research is supported by grants from the National Science Foundation and the Bureau of Land Management.

November 17 2015

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