Distinctive features of the first bird and Archeopteryx.

Archeopteryx is a genus of feathered dinosaur that was once the oldest known fossilized bird. The 11-12 specimens described date from about 150 million years ago to the Late Jurassic (163.5 million to 145 million years ago), and all have been found in limestone formations at Solfhofen in Bavaria, Germany, beginning in 1861. However, in the late 20th and early 21st centuries, other bird-like fossils of the same age were discovered, and their deposits in China prompted several paleontologists to classify Archeopteryx as a dinosaur.