Fossilized exoskeleton parts of barnacles in the genus Arcoscalpellum from the University of Alabama‘s Harrell Station Paleontological Site in Dallas County. They date to the Campanian age of the Cretaceous period, approximately 72 to 83 million years ago. Unlike the barnacles most commonly seen encrusting boats and marine life, these barnacles attached to surfaces with stalklike appendages.

Courtesy of the University of Alabama Museums/Alabama Museum of Natural History