A fossilized feather is simply called a fossil feather. When a feather or its remains are preserved in the fossil record, it can undergo various processes that lead to fossilization. Fossil feathers provide valuable information about ancient bird species, their plumage, flight adaptations, and evolutionary history. They can be used to study the evolution of feathers, track changes in feather morphology, understand the diversity of ancient bird groups, and reconstruct past avian ecosystems. Fossil feathers have been found in various types of deposits, including sedimentary rocks, shale, limestone, and fossil-rich formations. They can provide important insights into the appearance and behavior of ancient birds throughout geological time.