The Cryptic Antthrush also known as the Such's Antthrush, is a species of bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 in the Formicariidae

Formicariidae

The Formicariidae, formicariids, or ground antbirds are a family of smallish passerine birds of subtropical and tropical Central and South America. They are between 10 and 20 cm in length, and are related to the antbirds, Thamnophilidae, and gnateaters, Conopophagidae...

 family. It is endemic to Atlantic Forest in southeastern Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

. Although first described almost 200 years ago, it was long overlooked (hence, cryptic) due to confusion with the Rufous-tailed Antthrush

Rufous-tailed Antthrush

The Rufous-tailed Antthrush or Brazilian Antthrush is a species of bird in the Formicariidae family. It is endemic to Atlantic Forest in southeastern Brazil and far northeastern Argentina...

 and Short-tailed Antthrush

Short-tailed Antthrush

The Short-tailed Antthrush is a South American species of bird in the Formicariidae family. Its distribution is highly disjunct with populations in the Atlantic Forest in eastern Brazil, eastern Paraguay and northeastern Argentina, isolated highland forests in northeastern Brazil, forests on the...

, which inhabit the same region. The Cryptic Antthrush is mainly found at altitudes above the Short-tailed Antthrush, but below the Rufous-tailed Antthrush. When Nicholas Aylward Vigors

Nicholas Aylward Vigors

Nicholas Aylward Vigors was an Irish zoologist and politician.Vigors was born at Old Leighlin, County Carlow. He studied at Trinity College, Oxford. He served in the army during the Peninsular War from 1809 to 1811. He then returned to Oxford, graduating with a B.A. in 1815 and in 1817 with an...

 described this species in 1825, he based it on two specimen

Specimen

A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...

s collected by George Such, and this is the reason for the other common name, Such's Antthrush.