Thorius minutissimus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Caudata Plethodontidae

Scientific Name: Thorius minutissimus
Species Authority: Taylor, 1949
Common Name(s):
English Oaxacan Pigmy Salamander
Taxonomic Source(s): Frost, D.R. 2015. Amphibian Species of the World: an Online Reference. Version 6.0. New York, USA. Available at:
Taxonomic Notes: The name Thorius minutissimus has been applied to populations at other localities, but these are now known to belong to other species in the genus (Hanken and Wake pers. comm.).

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(iii) ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Gabriela Parra-Olea, David Wake, James Hanken
Reviewer(s): Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)
Listed as Critically Endangered because its Extent of Occurrence is less than 100 km2, all individuals are known from a single location, and there is continuing decline in the extent and quality of its habitat in south-eastern Oaxaca, Mexico.
Previously published Red List assessments:
2004 Critically Endangered (CR)

Geographic Range [top]

Range Description: This species is known only from one site near Santo Tomás Tecpan, in the Sierra Madre del Sur de Oaxaca, south-eastern Oaxaca, Mexico, at 2,458m asl.
Countries occurrence:
Number of Locations: 1
Lower elevation limit (metres): 2458
Upper elevation limit (metres): 2458
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Observed only twice in 60 years. Recently rediscovered (two specimens found at the type locality in 2001); this species is extremely rare, and very few specimens are known (Hanken and Wake pers. comm. 2007).
Current Population Trend: Decreasing
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: It lives terrestrially in pine-oak forest. It presumably reproduces by direct development.
Systems: Terrestrial

Threats [top]

Major Threat(s): The forests where it is found have been severely altered as a result of logging, agriculture, and human settlement, and very little good habitat remains.

Conservation Actions [top]

Conservation Actions: Habitat protection is the most urgently needed conservation action for this species, since it is not known from any protected areas. It is protected by Mexican law under the "Special Protection" category (Pr).

Citation: Gabriela Parra-Olea, David Wake, James Hanken. 2008. Thorius minutissimus. The IUCN Red List of Threatened Species 2008: e.T59417A11935966. . Downloaded on 25 November 2015.
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