Gymnotocinclus anosteos is a species of armored catfish (Loricariidae) endemic to Brazil, where it is found in the Tocantinzinho River in the Tocantins River basin.[1] This species grows to a length of 4.4cm (01.7inches) SL.
The genus Gymnotocinclus is unusual among the Loricariidae due to its extremely reduced armor plates that are characteristic of the family, giving the fish a relatively naked body.[1] This fish probably has a basal position in the subfamily Hypoptopomatinae.[1]