Theraphosinae is the most diverse subfamily of Theraphosidae spiders, but their evolutionary history remains unresolved to date. This problem is common in taxonomic groups with phylogenetic hypotheses that have often been based only on qualitative morphological characters and, rarely, on molecular analyses. Phylogenomics has significantly contributed to the understanding of the evolution ofmany non-model groups, such as spiders. Herein, we employed ultraconserved elements (UCEs) phylogenomics to propose a new hypothesis for a group of Theraphosinae genera, namely Lasiodoriforms: Vitalius, Lasiodora, Eupalaestrus, Pterinopelma, Proshapalopus, and Nhandu. We propose three genera and their respective morphological diagnoses are provided. Our phylogeny supports the transfer of species from the genus Vitalius to Pterinopelma and Proshapalopus and from Proshapalopus to Eupalaestrus. Finally, we describe a new species of Vitalius from Southern Brazil. Based on these three new generic descriptions and transferred species, the Lasiodoriform tarantulas comprise nine genera from Argentina, Brazil, Paraguay, and Uruguay, and the genus Vitalius now includes seven species.