The new genus Yanomamius n. gen. from Brazilian and Venezuelan Amazon is described, with three new species from Brazil: Y. franciscoi n. sp. (type species), Y. raonii n. sp., and Y. neblina n. sp. The enigmatic Venezuelan species described as Holothele waikoshiemi Bertani & Araújo, 2006 and presently included in Guyruita Guadanucci et al. (2007) is transferred to the new genus, making the new combination Y. waikoshiemi (Bertani & Araújo, 2006) n. comb. Yanomamius n. gen. is closely related with the schismatotheline genera Schismatothele Karsch, 1879 and Euthycaelus Simon, 1889 sharing as probable synapomorphies a group of short spines on the retrolateral distal tibia of male palp and the shape of bulb. They differ by the position of the spines in a compact group instead of in rows and by a tapering embolus. Females differ from Schismatothele and Euthycaelus by the spermathecae weakly sclerotized. A series of recent phylogenies based on molecular data suggested a close relationship between schimatothelines and psalmopoeines. The male tibia I of Yanomamius n. gen. species have a series of ridges or a single protuberance behind the tibial apophyses that resemble those of psalmopoeines and strengthen the idea of close relationship of the two subfamilies.
A new species of Ami Pérez-Miles, 2008 is described from the state of Amazonas in Brazil based on three males from Manaus. Ami valentinae sp. nov. is closely related to A. armihuariensis and A. caxiuana by the presence of a granular area on the embolus, but it differs from the first species by the presence of two retrolateral process on the male palpal tibia and differs by the latter by the morphology of the male palpal organ. A. valentinae sp. nov. is the first species of Ami reported for the Amazonas state and second species described for Brazil.
We present the first record for Theraphosa apophysis (Tinter, 1991) for Brazil. A male of T. apophysis was collected in São Gabriel da Cachoeira, Amazonas state, Brazil. This is the third species of Theraphosa in Brazil along with T. blondi (Latreille, 1804) and T. stirmi Rudloff & Weinmann, 2010.