Which is the only extant species of the genus charadriiform?

The razorbill (Alca torda) is a North Atlantic colonial seabird and the only extant member of the genus Alca of the family Alcidae, the auks. It is the closest living relative of the extinct great auk (Pinguinus impennis). Historically, it has also been known as "auk", "razor-billed auk" and "lesser auk".

Razorbills are primarily black with a white underside. The male and female are identical in plumage; however, males are generally larger than females. This agile bird, which is capable of both flight and diving, has a predominantly aquatic lifestyle and only comes to land in order to breed. It is monogamous, choosing one partner for life.

Presently, this species faces major threats, including the destruction of breeding sites, oil spills, and deterioration of food quality.

Alca is a genus of charadriiform bird that contains a single extant species, the razorbill (Alca torda). Many fossil species are known, the oldest dating back to the Miocene.

Species are:

Alca torda, Alca ausonia, Alca carolinensis,

Alca grandis, Alca minor, Alca olsoni, and

Alca stewarti.