The Ingersoll Shale is an informal Late Cretaceous geological unit in eastern Alabama from the Santonian age. Rather than a large named formation, it survives as a small clay-rich body within the region’s sedimentary record. The unit forms a clay-dominated lens with an asymmetrical cross-section, reaching about 90 centimeters in thickness and less than 30 meters in estimated width. Its significance far exceeds its size because it preserved fourteen theropod feathers, attributed to birds and possibly dromaeosaurids, making it an important fossil site in North American Mesozoic rocks.