The Miocene has yielded by far the greatest number of bird-bones, including even eggs and imprints of feathers.
The imprints in the enormously older new red sandstone or Lower Trias of Connecticut, and originally named Ornithichnites, belong to Dinosaurian Reptiles.
The character of this skull and the compound rhamphotheca (known by the imprints left upon the jaws) indicate affinities with the Steganopodes.
Ephemeridae belong to a very ancient type of insects, and fossil imprints of allied forms occur even in the Devonian and Carboniferous formations.
The first of the numerous imprints of the Historia Polonica appeared in 1614, the first complete edition in 1711.