Thorius adelos
family: Plethodontidae
subfamily: Hemidactyliinae
Taxonomic Notes: This is a small species known from fewer than 10 individuals. It has not been seen for many years, but the habitat in which it occurred is intact. It was originally placed in Nototriton, but when that taxon was subdivided by Garcia-Paris and Wake (2000, Copeia) it ended up in a new genus Cryptotriton. What made this assignment problematic was the fact that adelos was the only member of the genus north/west of the Isthmus of Tehuantepec. Wake, Rovito, Maisano and Hanken (2012, Zootaxa) studied ct scans of the skeleton of a specimen and concluded that adelos is a member of Thorius, despite the fact that it lacks the subocular groove, present in all other species of Thorius. Several unique osteological features demonstrate that it is in the Thorius clade and should be assigned to that genus. These include the presence of a large dorsal fonatanelle in the skull and a columnar posterior process of the squamosal (see for osteological features).
Conservation Status (definitions)
IUCN (Red List) Status Endangered (EN)
Other International Status None
National Status None
Regional Status None

Country distribution from AmphibiaWeb's database: Mexico


View distribution map using BerkeleyMapper.


From the IUCN Red List Species Account:


Range Description

This species is known only from the Atlantic slopes of the Sierra de Juarez, Pena Verde, and at Sierra de Mazateca on the Guelatao-Vista Hermosa transect, north-central Oaxaca, Mexico. Its altitudinal range is 1,530-2,050m asl. The species is presumed to occur between the known localities in appropriate habitat, but further data are required.

Habitat and Ecology

The species inhabits undisturbed cloud forests, being found in bromeliads and other epiphytic plants, and in leaf-litter, and does not tolerate disturbance of its habitat. It is terrestrial and reproduces by direct development.


It is still occasionally recorded but considered to be very rare.

Population Trend


Major Threats

The major threat to the species is loss of habitat due to logging, expanding agricultural activity, and human settlements.

Conservation Actions

It has not been recorded in any protected areas, making formal protection of its remaining cloud forest habitat an urgent priority.

Red List Status

Endangered (EN)


Listed as Endangered because its Extent of Occurrence is less than 5,000 km2, it is severely fragmented, and there is continuing decline in the extent and quality of its habitat in Oaxaca, Mexico.


Gabriela Parra-Olea, David Wake, James Hanken 2008. Thorius adelos. The IUCN Red List of Threatened Species 2008: e.T59233A11904017. .Downloaded on 17 November 2018


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