A new species of South American side-necked turtle is described from the state of Piauí, Brazil. It is related to the Amazonian species of the genus Mesoclemmys s.l. (new acceptation) and is apparently a biogeographically relictual population of a species formerly living under a more humid climate in northeastern Brazil.
BOUR, R., & ZAHER, H. (2005). A NEW SPECIES OF MESOCLEMMYS, FROM THE OPEN FORMATIONS OF NORTHEASTERN BRAZIL (CHELONII, CHELIDAE). Papéis Avulsos de Zoologia, 45(24), 295–311. https://doi.org/1807-0205