Duellman et al. (2016, Zootaxa 4104: 1–109) restricted Hyla to Eurasia and North Africa and referred the North American and east Asian sister taxa of this group to Dryophytes, although the acceptance of this taxonomy within the user community is controversial at this point.

Based on a re-analysis of previously published molecular data, Duellman et al. (2016, Zootaxa 4104: 1–109) restricted the name Pseudacris to the eastern and Rocky Mountain species related to P. nigrita and allocated the western species, P. cadaverina, P. hypochondriaca, P. regilla, and P. sierra to Hyliola Mocquard, 1899. Based on genome-wide nDNA data, Banker et al. (2020, Systematic Biology 69: 756–773) argued that Hyliola should not be recognized because (a) the genus Pseudacris already is a monophyletic taxon without the change, and (b) the geographic separation rationale cited by Duellman et al. (2016, Zootaxa 4104: 1–109) is insufficient as the sole criterion for splitting a long-recognized monophyletic clade, causing unnecessary taxonomic instability. Use of Hyliola has not gained any traction in the systematic community, presumably because of the small number of species involved.

The generic taxonomy of American ranids is controversial, with three nomenclatural arrangements being consistent with current understandings of phylogeny. Reasonable but subjective arguments could be made for any of these three taxonomies. The least particulate is the single-genus arrangement of Yuan et al. (2016, Systematic Biology, 65: 824–842), which placed all Eurasian Rana and Pseudorana as well as all American ranids into Rana (thus including approximately 115 species). There is the three-genus model of Che et al. (2007, Molecular Phylogenetics and Evolution 43: 1–13), largely in agreement with the earlier arrangement by Frost et al. (2006, Bulletin of the American Museum of Natural History, (297): 1-370), which recognizes Pseudorana in Asia, Rana in Eurasia and western North America, and Lithobates in the Americas. The three-genus model has been widely, but not uniformly, accepted in publications for more than 15 years and this suggests relative taxonomic stability in a group sometimes considered to be controversial. Most recently, Dubois et al. (2021, Megataxa 5: 1–738) presented a seven-genus model that recognizes Pseudorana, Rana, and Liuhurana in Eurasia and Amerana (the Pacific Coast ranids of North America), Aquarana (for the bullfrogs and allies), Boreorana (a monotypic genus for Wood Frog, L. sylvaticus), and Lithobates (for the leopard frogs and allies). Although understanding of the phylogeny of these frogs appears to be stabilizing and the seven-genus model provides the most morphological coherence of units within the overall phylogeny as currently understood, we defer from recognizing Amerana, Aquarana, or Boreorana at this time pending achievement of more phylogenetic stability, especially with respect to the position of the taxon sylvaticus which inconsistently is recovered as sister to the proposed Aquarana or as sister to Lithobates. Because both the three-genus model and the seven-genus model embrace monophyly as a basic principle, the perspectives on the preferred taxonomy are subjective, and this subjectivity is the root of the ongoing controversy among mostly U.S. herpetologists regarding the generic allocations of these frogs. The recent seven-genus model may be unpopular in some circles, particularly in the U.S., so we do not think that the controversy will be resolved in the near-term.

The taxon Amerana Dubois, 1992 (Bulletin Mensuel de la Société Linnéenne de Lyon, 61: 305–352) was applied to this group of species from western North America as a subgenus based on phenetic criteria. It was recognized as a genus by Fei et al. (2010, Herpetologica Sinica 12: 1–43) and by Dubois et al. (2021, Megataxa 5: 1–738) based on phylogenetic criteria. We have chosen not to recognize Amerana at this time, pending a more stable phylogeny for the North American ranids, especially with respect to Lithobates sylvaticus. See additional comments under Lithobates.