The arboreal Neotropical “thorellii” clade of Centruroides Marx, 1890, bark scorpions (Buthidae C.L. Koch, 1837) is revised, using a novel approach to species delimitation. A phylogenetic analysis, based on 112 morphological characters and 1078 aligned DNA nucleotides from the mitochondrial Cytochrome c Oxidase Subunit I (COI) gene, provided the framework for placing singletons from geographically disparate localities (and often with suboptimal preservation) using COI minibarcodes, thereby enlarging the taxon sample for diagnosis and delimitation of morphological species. Six new species are described, tripling the known diversity in the clade to nine: Centruroides berstoni, sp. nov.; Centruroides catemacoensis, sp. nov.; Centruroides chanae, sp. nov.; Centruroides cuauhmapan, sp. nov.; Centruroides hamadryas, sp. nov.; Centruroides yucatanensis, sp. nov. Revised diagnoses are presented for Centruroides hoffmanni Armas, 1996, Centruroides rileyi Sissom, 1995, and Centruroides schmidti Sissom, 1995. Comparative images, a key and distribution maps for all species of the clade are provided, along with a summary of available data for their ecology.