Specimens of Archaeopteryx length. These hindlimb proportions agree roughly with those of the London specimen. The claw arc of the central pedal digit is about 120 degrees, which is close to the average for all "Archaeopteryx" specimens. This arc is also close to the average for that in perching birds and is well above the mean for ground-dwelling birds, despite conclusions against perching habits based on the short hallux and weak flexor tubercles. The remarkably preserved plumage is one of many features that sets the Berlin specimen head-and-coracoids above all other "Archaeopteryx" fossils to date. Clear feather impressions are visible on both wings,
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