Introduction to the Morphology, Development, and Ecology of Feathers

Abstract

Feathers are a characteristic of modern birds that differentiate them from all other extant non-avian reptiles. The origin of feathers goes back deep into the Mesozoic, preceding the origin of flight, and early protofeathers were probably present in the ancestral Tetanurae, Dinosauria, or even Ornithodira. Among extant vertebrates, the feathers of modern birds are morphologically the most complex integumentary structure with enormous shape diversity resulting from a hierarchical organization of repetitive morphological and developmental modules. In this chapter, the morphological ground patterns of modern feathers, their underlying developmental processes, and the biological roles of different feather types are reviewed.