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 be related particularly closely to "Anchiornis" and "Xiaotingia", which were recovered as basal troodontids instead. Agnolín and Novas (2013) found "Archaeopteryx" and (possibly synonymous) "Wellnhoferia" to be the basalmost avialans (Avialae being defined by the authors as including "Archaeopteryx lithographica" and "Passer", their most recent common ancestor and all of its descendants), with Microraptoria, Unenlagiinae, and the clade containing "Anchiornis" and "Xiaotingia" being successively closer outgroups to the Avialae. Another phylogenetic study by Godefroit, "et al.", using a more inclusive matrix than the one from the analysis in the description of "Eosinopteryx brevipenna", also found "Archaeopteryx" to be a member