Archaeopteryx

Archaeopteryx is an extinct genus of early avialan dinosaurs from the Late Jurassic, widely regarded as one of the earliest known birds or near-bird dinosaurs. It is considered a transitional fossil that displays a mix of both avian and non-avian features, illustrating the evolutionary link between theropod dinosaurs and birds.

Fossils of Archaeopteryx have been recovered from the Solnhofen limestone formation in Bavaria, Germany, dating to about 150 million years ago. The first skeleton was described in 1861, and several well-preserved specimens with impressions of feathers have been found since. These fossil discoveries provided some of the most compelling evidence for the dinosaur-bird transition and for the origin of flight in birds.

Anatomically, Archaeopteryx possessed wings with clearly formed flight feathers and a tail adorned with feather impressions, indicating avian affinities. It also retained numerous theropod traits, such as teeth in the jaws, a long bony tail, and clawed fingers. A furcula, or wishbone, is present, as in modern birds. However, the sternum lacks a pronounced keel, which suggests it may have been capable of limited powered flight or primarily gliding rather than sustained flapping like contemporary birds.

Significance and classification: Archaeopteryx occupies a central place in discussions of avian origins and early bird evolution. It is generally placed within Avialae and is viewed as a key transitional form between non-avian dinosaurs and true birds. Ongoing research continues to refine its taxonomy and to clarify its flight capabilities and ecological role during the Jurassic.