Phelps & Wetmore, 1956
The Táchira Antpitta (Grallaria chthonia) is a cryptical bird species. It is provisionally placed in the family Grallariidae, pending revision of this group. This species was only sighted and collected between 1955 and 1956, and may be extinct.
The Táchira Antpitta reaches a length of 17 cm. Its upperparts are brownish. Crown and nape are coloured grey. The mantle has black barrings. Throat and ear coverts are brown. It is further characterised by a white malar stripe. The lower belly is whitish, the flanks and the breast have grey barrings.
The Táchira Antpitta was last seen in 1956. Between 1955 and 1956 the ornithologists William Henry Phelps and Alexander Wetmore collected four specimens in the type locality at the hacienda La Providencia at the Rio Chiquita in the south-western part of Táchira, Venezuela. The type locality is located in the El Tamá National Park where some suitable habitat still remains. However, between 1990 and 1996 the cloud forest in the Rio Chiquita valley - including parts of the national park and the type locality - was entirely changed into coffee plantations below 1,600 m ASL, and largely cut down for vegetable gardens between 1,900 and 2,200 m ASL.
Despite extensive searches from 1990 to 1996, this species has not been observed since more than half a century. It was formerly classified as Endangered by the IUCN. But with current research failing to relocate this species, it is uplisted to Critically Endangered status in 2008.