While assignment of such a fragmentary fossil is always problematical, the ulna is a fairly distinctive bone and that of Alcodes is quite peculiar. However, it is more allied with the Mancallines as a matter of convenience; additional material would be needed to confirm this relationship. From the bone's measurements, it seems probable that this species was flightless and judging from its age, it either represents an earlier development parallelling Mancalla, or a third lineage of flightless auks. Praemancalla is known from Clarendonian to Early Pliocene remains. It is similar to Mancalla, but less extreme in its adaptations and it is quite possibly that the latter genus evolved from one of the two known species. Mancalla was a common species throughout the Pliocene, appearing in the Hemphillian stage of the Late Miocene (5–9 mya), and spreading in the Pliocene, with 4 species apparently coexisting at one time on the coast of southern California. As with many marine birds, the mancalline auks were much affected by the extinction crisis in the late Pliocene oceans. This coincided with the diversification of marine mammals, but may ultimately have been caused by increased supernova activity in the vicinity of the solar system. Despite their apparent awkwardness, they seem to have been quite well adapted for flightless birds, with the fossil record suggesting that the last remnants did not disappear until the Early Pleistocene (c. 7 mya), some time after the ecological changes had passed their peak. References Auks Extinct flightless birds Neogene birds Bird subfamilies