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Dr. Benjamin Dattilo
Department of Geosciences
Indiana University – Purdue University Fort Wayne
Fossilized remains of an unknown species of cyprinidontiformes (top minnows/pupfish) fish were recovered on the grounds of the Nevada Test Site (area of which is currently closed off to the public). The specimens were found in Miocene volcaniclastic lake sediments and range in size up to 10 cm. The original bone material of most specimens was missing, leaving highfidelity natural molds in hard silicified silt. Silicone rubber molding compound was used to reproduce the original appearance of the bones. Images of these rubber casts were made with a high-resolution, flat-bed scanner and with a scanning electron microscope. From these images it is possible to compare the skeletal structure of these fish to modern fish, and to other Miocene fish fossils. While the species has not yet been determined, it appears that only one species is represented, suggesting a stressed environment in these volcanic lakes. The highresolution casts also show growth lines on the scales and ostracods in the gut, giving a clue to the food web of the original community. This study gives us a window into the late Cenozoic era, and the environment of the fish. Like their ancient counterparts, modern topminnows live in extreme habitats. Finding how these fish met their end could give us insight into how we might protect similar, threatened, species today.
Earth Sciences | Physical Sciences and Mathematics
Stoller, Michael and Gillespie, Robert B. Ph.D, "Osteology of Miocene fossil fishes from the Nevada Test Site" (2015). 2015 IPFW Student Research and Creative Endeavor Symposium. 65.