Black tinamou  The black tinamou ("Tinamus osgoodi") is a species of ground bird found in humid foothill and montane forest in the Andes of South America. All tinamous are from the family Tinamidae and members of the infraclass Palaeognathae. Tinamous are the only members from their infraclass that aren't ratites, and can even fly, albeit poorly. All paleognaths evolved from prehistoric flying birds, and tinamous are the closest living relative of these birds. This species of tinamous was first described by Henry Boardman Conover in 1949 based on a specimen from Cusco in Peru. It has two subspecies:  The black tinamou is a stocky terrestrial bird with a short tail and rounded wings. It is comparatively larger than other tinamous and tends to be about long, with females being a little larger than males. A male black tinamou has an average wingspan of about , and a female black tinamou has an average wingspan of . While there is no record of the average mass of a black tinamou, a male specimen weighing has been examined at the Field Museum of Natural History. It is primarily slate grey, rather than truly black as its name would imply. The upperparts of an adult black tinamou are a uniform grey, while its midsection and greater wing coverts are sometimes edged with brown. Its lower breasts and flanks are a sooty brown color, as well as its belly. It has a rufescent vent, which may or may not have black speckling, depending on the subspecies. Its maxilla is black, and its mandible is a light grey. The black tinamou has blue-grey legs and dark brown eyes. An adolescent black tinamou is similar in color, but with whitish spots on the coverts of its wings. Black tinamou chicks generally have a light brown head with a broad, cinnamon-brown stripe extending from the crest of their heads to the napes of their necks. They have whitish throats and chins. Their neck, upper back and upper breast are a dusty brown. A black tinamou chick's lower back and rump is a dirty buff color, and its lower breast and belly range from dusky brown to pale brown. The black tinamou has a tremulous and descending whistle lasting about one second. The whistle is similar to that of a white-throated tinamou, even sharing the same first note.