A Glimpse into a Middle Devonian Ecosystem; Penn Dixie Fossil Beds, Erie County, New York

Penn Dixie Fossil Quarry and Nature Reserve is an educational center located in Erie County, New York. It provides an opportunity for individuals to explore the geology and paleontology of Western New York. The Reserve allows visitors to collect fossils to study and to dig for simple fascination. The diverse fossil assemblage preserved in the rocks provide researchers with a unique opportunity to learn about life in the past. The fossil faunas collected at this location were used to reconstruct the Middle Devonian (393-382 million years ago) paleoenvironment. The Devonian was a pivotal period in the history of life on Earth as plants were beginning to populate land and early tetrapods were experimenting with life out of the water. Marine invertebrates were also thriving in newly formed tropical marine environments. Intense tectonism was occurring as island arcs began to accrete to the eastern margin of North America. This resulted in a mountain range along the east coast with extensive, deltaic river systems draining toward the west into an interior marine basin. Life thrived along the edge of the delta, and diverse organisms interacted forming unique ecosystems. The rocks deposited at this location belong to the Middle Devonian Hamilton Group, specifically the Windom Shale of the Moscow Formation. This soft, fissile, medium-grey shale contains abundant fossil brachiopods, corals, trilobites, echinoderms, and bryozoans. The bryozoan and solitary rugose corals formed thickets that provided habitats for the trilobites, echinoderms, and brachiopods to flourish. The faunal assemblage collected from Penn Dixie Fossil Quarry represents this unique ecosystem thriving along the edge of a well oxygenated marine basin during the Middle Devonian.