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 on the main slab. Both arms are preserved close to their natural articulation with the shoulder girdle, though displaced. The ulna is more robust and curved than the slender radius. A confusing jumble of metacarpals has led some researchers to conclude the beginning of fusion between carpals and metacarpals; this has been rejected by later researchers. Most manual bones of the right wing are missing, and the left wing preserves two metacarpals, the semilunate carpal, and two long, slender phalanges with large, strongly-curved claws. The missing third finger led Owen to conclude a two-fingered hand for "Archaeopteryx" in his original