12-Fossiliferous limestone

Limestone slab showing brachiopod fossils. This rock surface is part of an ancient seafloor, and the brachiopod fossils are shells of extinct marine animals. The brachiopods lived in an epicontinental sea that flooded the Midwest during Middle Devonian time, about 385 million years ago. Rock slab is from the top of the rock sequence in the May Stone and Sand Ardmore Avenue quarry, Fort Wayne.