Turnstone traits are apomorphic and plesiomorphic, it may be an ancestral representative of either lineage. Turnstone Turnstones are two bird species that comprise the genus Arenaria in the family Scolopacidae. They are closely related to calidrid sandpipers and might be considered members of the tribe Calidriini. The genus name "arenaria" is from Latin "arenarius", "inhabiting sand", from "arena", "sand". Both birds are distinctive medium-sized waders. Roughly speaking, length is typically between 20 and 25 cm, with a wingspan between 50 and 60 cm and a body mass between 110 and 130gm. For waders their build is stocky, with short, slightly upturned,
Black turnstone and breast become largely dark brown with little white. Juveniles are similar to winter adults but browner with buff fringes to the wing-coverts and scapulars and a grey-brown tip to the tail. The ruddy turnstone is similar but has rufous-brown markings on the upperparts and more white on the head and breast, particularly in breeding plumage. It has narrower wings and a narrower white wingbar. Its legs are orange and brighter than those of the black turnstone though there can be some overlap. The black turnstone has a variety of calls, especially a rattling trill which can be heard throughout