Archaeopteryx 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 derives from the ancient Greek ("archaīos") meaning "ancient", and ("ptéryx"), meaning "feather" or "wing". Between the late nineteenth century and the early twenty-first century, "Archaeopteryx" had been generally accepted by palaeontologists and popular reference books as the oldest known bird (member of the group Avialae). Older potential avialans have since been identified, including "Anchiornis", "Xiaotingia", and "Aurornis". "Archaeopteryx" lived in the Late Jurassic around
Archaeopteryx or trunk-climbing lifestyle. This has been interpreted as evidence of theropod ancestry. In 1988, Gregory S. Paul claimed to have found evidence of a hyperextensible second toe, but this was not verified and accepted by other scientists until the Thermopolis specimen was described. "Until now, the feature was thought to belong only to the species' close relatives, the deinonychosaurs." The Thermopolis Specimen was assigned to "Archaeopteryx siemensii" in 2007. The specimen is considered to represent the most complete and best-preserved "Archaeopteryx" remains yet. The discovery of an eleventh specimen was announced in 2011, and it was described in 2014. It