It is pretty unusual to see fish in the UCMP. It’s not that we don’t have any fish specimens — we have over a million fossilized fish fragments. It’s just that none of our museum scientists focus on fish, and so the museum’s fish parts tend to stay in the cabinets. But this past summer, Ralph Stearley of Calvin College visited the UCMP, and he did a little fishing.
Ralph pulled some spectacular specimens from the murky depths of the cabinets. The two specimens shown here are exceptional — nearly all the bones are in place, and one of the specimens even has imprints of scales! It is really rare for fish to fossilize like this — most of the time, fish break apart into individual bones and tiny scales.
These two specimens are salmonids. They are related to salmon, char, and trout — their closest living relative is probably the Dolly Varden. They lived 15-10 million years ago, in the ancient lakes that back then dotted Western Nevada. They were collected by UCMP curator Howard Hutchison in 1975, in an area called Stewart Valley. This site contains fossilized vertebrate, insect, fish, and plant material — it is rare to find so much taxonomic diversity in one place. Hutchison and his colleagues really got a sense of the entire fauna that once inhabited the area.
Ralph was excited to find these salmonid specimens in our collection — he and his collaborator, Gerald Smith of the University of Michigan, study the biogeographic history of salmonid fish. These specimens provide evidence that salmonids once lived in Western Nevada. For Ralph and Gerald, these fish are definitely keepers.
Daniel Fortier visited the UCMP for two weeks this summer, investigating the taxonomy of South American crocodilians — crocodiles, caymans, and gharials. Daniel is from Brazil, where crocodiles are fairly common. He is a Ph.D. student at the Universidade Federal Do Rio Grande Do Sul in Porto Alegre, and is spending the year at the University of Iowa, in Iowa City. He is using fossils and modern skeletal materials to learn about crocodilian evolutionary history, places of origin, dispersal routes, speciation, and extinction events.
During the Miocene (from about 23 to 5 million years ago), Columbia was home to great crocodilian diversity. The UCMP has the best collection of Columbian crocodilian fossils. “Actually,” says Daniel, the UCMP “is the only one with Columbian fossils.”
This is a fossil gharial skull. Gharials (also called gavials) are a group of crocodilians with long, narrow jaws. They lived in South America during the Miocene, but are now extinct in South America. Gharials still live in parts of India. Daniel is trying to learn more about their evolution, biogeography, and extinction.
Daniel's visit was supported by the Welles Fund, an endowment that supports paleontological research at the UCMP. Click here to learn how you can support research at the UCMP.
David Dufeau, a graduate student from Ohio University, spent a few days at the UCMP this July, studying the development and evolution of the middle-ear sinuses in archosaurs — birds and crocodilians. He explains that the sinuses in these animals were so greatly expanded that they completely surrounded the braincase. By understanding these super-sized sinuses in the archosaurs, David hopes to infer something about the nature of auditory receptivity. Maybe the sinuses expanded as adaptations for hearing in terrestrial and aquatic habitats. David can look at the sinuses in fossilized skulls, but he has no way of knowing whether these animals suffered from middle ear infections or terrible sinus headaches.
David's visit was supported by the Welles Fund, an endowment that supports paleontological research at the UCMP. Click here to learn how you can support research at the UCMP.
This summer, Carolyn Rounds visited the UCMP to study our Moropus fossils. Carolyn is a grad student in Organismic and Evolutionary Biology at the University of Massachusetts Amherst. And Moropus is an extinct horse-like creature, part of a taxonomic group called chalicotheres.
Chalicotheres are pretty unique — they had claws instead of hooves. They didn’t use their claws to rip apart prey; they were herbivores, and they probably used their claws to pull vegetation down from trees. Chalicotheres lived in North America, Europe, Asia, and Africa; they are all now extinct. Chalicotheres are part of a larger group, the perissodactyls, or odd-toed ungulates. Living perissodactyls include horses, zebras, tapirs, and rhinos.
For her Masters degree, Carolyn is describing a species of Moropus that has not been described before — a new species. Here at the UCMP, she’s looking at fossils from the Flint Hill formation in South Dakota. The differences between Carolyn’s Moropus and the species that have already been described are subtle. The facets of the ankle bones — where the bones meet each other — have a slightly different shape than other species. The vertebrae of this species are also a bit different. Carolyn is taking careful notes and making beautiful drawings of the UCMP fossils, so she can compare them to fossils she’s examining at other museums. This summer, she’s making a grand tour of natural history museums. So far, she’s visited The American Museum of Natural History in New York City, the University of Nebraska State Museum, and the South Dakota School of Mines. Next week, she’ll travel to the Los Angeles County Museum.