What Was The First Bird?

The remains of the first birds were found in 1861 in a limestone quarry in Bavaria. The second skeleton was discovered in 1877 and almost a century later, in 1956, the third. It is significant that all three skeletons were found at a distance of 15 km.
It is believed that all three skeletons belonged to the same species Archaeopteryx lithographica, in short Archaeopteryx.
This animal lived 150 million years ago.

Fossil of complete Archaeopteryx, including indentations of feathers on wings and tail
"Archaeopteryx lithographica (Berlin specimen)" by H. Raab (User: Vesta) - Own work. Licensed under CC BY-SA 3.0 via Commons.