Euathlus Ausserer, 1875 is a South American genus of spiders of the family Theraphosidae known from Chile and Argentina. Three new species from Argentina: Euathlus mauryi sp. n. (from San Juan province), Euathlus grismadoi sp. n. (from La Rioja province), and Euathlus pampa sp. n. (from Salta province) are described here. New records of the previous species Euathlus diamante and Euathlus tenebrarum are contributed. The distribution of these new species expands the geographical distribution of the genus along the Andean hills, with Salta province as the northernmost record of the genus. A key is provided for identification of Euathlus species as well as a map with all the records in Argentina.
New specimens of the genus Hapalotremus (Theraphosinae) are revised based on the examination of types and additional material collected in Argentina, Bolivia and Peru. A new generic diagnosis is proposed. New information and illustrations are provided for known species and seven new species were recognized and are newly described and illustrated. Hence, Hapalotremus comprises 10 valid species, distributed along the Andes and Yungas in western South America. All species are keyed and mapped. New taxonomic features are included in the descriptions and the detail of embolus keels morphology and positions are described for the first time for the genus. Information on species habitat is included. The highest altitude record for a Theraphosidae spider, living at 4524 m above sea level, is reported.
A detailed re-description of the type specimen of Trichopelma cubanum (Simon, 1903) is presented. Comments and observations are made regarding morphological characters, such as the absence of teeth on the paired claws and the presence of small teeth on the anterior edge of the booklung opening. These characters, found in other species of Trichopelma Simon, 1888 (represented in the Neotropical region by 16 species), suggest that the recent transfer of the genus to Theraphosidae may be unjustified, and that Trichopelma may indeed be more closely related to the Barychelidae.