Specimens of Archaeopteryx original classification of a new taxon, "Archaeopteryx bavarica". The hind limbs, while showing no morphological differences from previously known specimens, were perhaps the best preserved yet and showed some unprecedented details. For example, the right foot was preserved so tightly flexed that the claws of the first and fourth toes are overlapping, indicating that a grasping or perching function was present in "Archaeopteryx", possibly as sophisticated as that of modern birds. Only the imprints of wing and tail feathers are present, and all sign of feathers comes from the counterslab. No body feathers are evident. The right wing displays a
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