This presentation will illustrate how microtomographic imaging of some famous but also contentious fossil hominid teeth from Africa and Asia helps to revise the taxonomic diagnosis and to reconstruct phylogenetic relationships. The first example will focus on Africa fossils. Following recent fossil discoveries, the South African Plio-Pleistocene hominin diversity is increasing, with the inferred (co)existence of a number of species representing the three genera Australopithecus, Paranthropus and Homo. For the latter taxon, three Early Pleistocene species have been proposed, including H. habilis, H. erectus/ergaster, H. gautengensis, and one Middle Pleistocene taxon, H. naledi, was recently described. But is this taxonomic diversity real or the result of incorrect attributions to the genus Homo? In a second example, the issue of hominid paleodiversity in Asia will question the variability of Homo erectus and the potential existence of one or more unrecognized “mystery ape” taxa in the fossil record.