Data from: Genetics, morphology, advertisement calls, and historical records distinguish six new polyploid species of African clawed frog (Xenopus, Pipidae) from West and Central Africa

African clawed frogs, genus Xenopus, are extraordinary among vertebrates
in the diversity of their polyploid species and the high number of
independent polyploidization events that occurred during their
diversification. Here we update current understanding of the evolutionary
history of this group and describe six new species from west and central
sub-Saharan Africa, including four tetraploids and two dodecaploids. We
provide information on molecular variation, morphology, karyotypes,
vocalizations, and estimated geographic ranges, which support the
distinctiveness of these new species. We resurrect Xenopus calcaratus from
synonymy of Xenopus tropicalis and refer populations from Bioko Island and
coastal Cameroon (near Mt. Cameroon) to this species. To facilitate
comparisons to the new species, we also provide comments on the type
specimens, morphology, and distributions of X. epitropicalis, X.
tropicalis, and X. fraseri. This includes significantly restricted
application of the names X. fraseri and X. epitropicalis, the first of
which we argue is known definitively only from type specimens and possibly
one other specimen. Inferring the evolutionary histories of these new
species allows refinement of species groups within Xenopus and leads to
our recognition of two subgenera (Xenopus and Silurana) and three species
groups within the subgenus Xenopus (amieti, laevis, and muelleri species
groups).