Euathlus

Dominik Alexander
Nov 22
2 min read

Euathlus is a genus of South American tarantulas first established by Anton Ausserer in 1875, with Euathlus truculentus designated as the type species. These are small- to medium-sized terrestrial tarantulas, mostly from temperate, often higher-elevation habitats along the Andes in Chile and Argentina, with a few species reaching northern Chile and southern Peru.

The group has a famously tangled taxonomic history. Over the last century various Chilean and Mexican species were shuffled into and out of Euathlus, and at one point the genus was even treated as a senior synonym of Brachypelma before later studies rejected that idea. Modern revisions using detailed morphology and cladistic analyses re-defined the genus, synonymised the Chilean genus Paraphysa with Euathlus, and revalidated Phrixotrichus, which cleaned up many of the earlier misplacements.

Recent work continues to add species and refine its range. New descriptions from Argentina, Chile and Peru have expanded the genus and produced the first confirmed records for Peru (E. vanessae) and for the far-northern Chilean region of Tarapacá (E. walteri), highlighting that some Euathlus are very localised and potentially vulnerable to habitat change. As of the latest updates, the World Spider Catalog recognises roughly 17 valid Euathlus species, all restricted to South America and concentrated in Chile and Argentina.