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
Specimens of Archaeopteryx that "Archaeopteryx" could have raised its short second toe in a similar manner to its dromaeosaur cousin "Deinonychus", whose second toe bore an enlarged "sickle claw" for probable use in predation. It remains unclear whether "Archaeopteryx" also used its hyperextended toe-claw in a similar fashion or for some other purpose. Taken together, many of the unique features of the skull, feet and coracoid strengthen a close relationship of archaeopterygids to deinonychosaurian theropods. Well-preserved imprints of wing and tail plumage show details of the barbs, but not barbules, and the shafts of 11 primaries can be counted on the right wing.