Archaeopteryx (är´kēŏp´tərĬks) [Gr.,=primitive wing], a 150 million-year-old fossil animal first discovered in 1860 in the late Jurassic limestone of Solnhofen, Bavaria, and described the following year. All eight known fossils of Archaeopteryx, discovered between 1860 and 1992, were found in a 516 sq-mi (1,336 sq-km) area of the Solnhofen quarries. First classified as a bird because of the presence of feathers and the structure of the legs and wings, it nevertheless has many characteristics now found only in reptiles or in bird embryos. It was long regarded as the most primitive known bird, but more recent discoveries of fossils that have feathers and other birdlike features while also retaining strong dinosaurlike characteristics has led some to argue that Archaeopteryx is in fact a feathered dinosaur that should be grouped with the theropods. It is still debated whether Archaeopteryx, which was about the size of a pigeon or grackle, was arboreal or a swiftly running terrestrial animal and poor flyer; its feathers appear to have been too weakly constructed to be useful for active flight. Some claimed that a fossil discovered in West Texas in 1983 and dubbed Protoavis represents a primitive bird that predated Archaeopteryx by some 75 million years, but many experts also have questioned whether Protoavis is in fact a bird or even an correctly reconstructed animal.

See L. M. Witmer, The Search for the Origin of Birds (1995); A. Feduccia, The Origin and Evolution of Birds (1996); S. Chatterjee, The Rise of Birds (1997); P. Shipman, Taking Flight: Archaeopteryx and the Evolution of Bird Flight (1998).

Archaeopteryx lithographica The first known bird, of which only six specimens and one feather imprint have been found, all of them from the Lithographic Limestone of the Solnhofen region of Bavaria, Germany. The bird was first described by H. von Meyer in 1861 and is of Middle Kimmeridgian (Upper Jurassic) age. Work by several palaeontologists tends to support the theory that the birds, through Archaeopteryx, evolved from coelurosaur dinosaurs (Coelurosauria) similar to Compsognathus. The species A. lithographica possesses several primitive characters such as teeth, as well as specialized features such as feathers and hollow bones. It is a good example of a connecting species which exhibits a mosaic of evolutionary features.

Archaeopteryx lithographica Only five specimens of this species, the first bird, are known. Archaeopteryx is recorded solely from the Lithographic Limestone of the Solnhofen region of Bavaria, Germany. It was first described by H. von Meyer in 1861 and is of Middle Kimmeridgian or Upper Jurassic age. Recent work on this species by several palaeontologists tends to support the theory that the birds, through Archaeopteryx, evolved from coelurosaur dinosaurs similar to Compsognathus. The species A. lithographica possesses several primitive characters such as teeth, as well as specialized features such as feathers and hollow bones. It is a good example of a connecting species which exhibits a mosaic of evolutionary features.

archaeopteryx First known bird. About the size of a crow and fully feathered, its fossilized skeleton is more like that of a reptile than a modern bird, and its beak had pronounced jaws with teeth. It was capable probably only of weak flight.

http://www.ucmp.berkeley.edu/diapsids/birds/archaeopteryx.html