Specimens of Archaeopteryx in 1860 or 1861 and described in 1861 by Christian Erich Hermann von Meyer. The fossil consists of two counterslabs, designated BSP 1869 VIII 1 (main slab) and MB.Av.100 (counterslab). Its two counterslabs are currently located at the Bavarian State Collection of Paleontology and Geology of Munich University and the Natural History Museum in Berlin, respectively. This feather is generally assigned to "Archaeopteryx" and was the initial holotype, but whether it actually is a feather of this species or another, as yet undiscovered, avialan is unknown. There are some indications it is not from the same animal as most of
Archaeopteryx are limited to a sort of "proto-down" not dissimilar to that found in the dinosaur "Sinosauropteryx": decomposed and fluffy, and possibly even appearing more like fur than feathers in life (although not in their microscopic structure). These occur on the remainder of the body—although some feathers did not fossilize and others were obliterated during preparation, leaving bare patches on specimens—and the lower neck. There is no indication of feathering on the upper neck and head. While these conceivably may have been nude, this may still be an artefact of preservation. It appears that most "Archaeopteryx" specimens became embedded in anoxic