Epidexipteryx

Epidexipteryx is a genus of small, feathered paravian dinosaurs from the Late Jurassic period, specifically from the Solnhofen Formation in China. It is known from a single exceptionally preserved fossil specimen, which has provided significant insights into the evolution of feathers and the early diversification of birds.

The name Epidexipteryx means "illustration feather" in Greek, referring to the unique and elaborately developed feathers found on its forelimbs. These feathers, unlike those of modern birds, lacked a central rachis and were more like filamentous strands. They are thought to have been ornamental rather than for flight. The dinosaur itself was small, estimated to be around 30 centimeters long, with a relatively short tail and a distinctive beak-like snout.

Its skeletal features suggest it was a theropod dinosaur closely related to the lineage that led to birds. The combination of bird-like feathers and reptilian characteristics makes Epidexipteryx a crucial piece in understanding the transition from non-avian dinosaurs to birds. It demonstrates that some early bird-like dinosaurs possessed complex feather structures for purposes other than flight, such as display or thermoregulation. The discovery of Epidexipteryx has contributed to the ongoing debate about the function and evolution of feathers in the Mesozoic Era.