Archaeopteryx of Avialae (defined by the authors as the most inclusive clade containing "Passer domesticus", but not "Dromaeosaurus albertensis" or "Troodon formosus"). "Archaeopteryx" was found to form a grade at the base of Avialae with "Xiaotingia", "Anchiornis", and "Aurornis". Compared to "Archaeopteryx", "Xiaotingia" was found to be more closely related to extant birds, while both "Anchiornis" and "Aurornis" were found to be more distantly so. Archaeopteryx Archaeopteryx (), meaning "old wing" (sometimes referred to by its German name ("original bird" or "first bird")), is a genus of bird-like dinosaurs that is transitional between non-avian feathered dinosaurs and modern birds. The name
Specimens of Archaeopteryx 1998, Vieser 1988). The Eichstätt specimen of "Archaeopteryx" is represented by an almost-complete skeleton visible on both slab and counter-slab, though the majority of the skeleton is on the main (overlying) slab. The animal is preserved lying on its right side, as in the Berlin specimen. The specimen is in almost complete articulation with many items in their original positions. The vertebral column, which had become strongly recurved in death, enabled the animal's head to lie above the pelvis in near-perfect preservation. This excellently-preserved skull is one of the most notable features of this specimen. The majority of the Eichstätt