Among the fifteen Bufo species we examined, only nine are represented in this piece of the Tree of Life from Frost et al. Nonetheless, with the addition of Dendrobates auratus and Melanophryniscus stelzneri (which we presume would be associated here with M. klappenbachi), we cover this terminal region of the Hyloides limb rather well. In M. stelzneri, we found no caudal extension. In Dendrobates auratus, the average proportion of total AP hair cells in the caudal extension was 0.36 (n = 2 animals, 4 APs). Among the 15 species of Bufo, the proportion ranged from 0.20 in an AP from B. debilis to 0.39 in APs from B. mauritanicus. The proportion was greater than 35% in only one other specimen—an AP from B. valliceps. It was less than 25% in B. punctatus as well as B. debilis. In addition to those mentioned above and those indicated by arrows in the tree, the Bufo species we examined included B. americanus, B. bocourti, and B. speciosus.