All three English names are misleading or potentially confusing. Many species in the genusBrachycephalus are bright yellow-orange, hence the name "Brazilian gold frog", butB. didactylus is all brown.[2] "Izecksohn's toad" leads to easy confusion with another species in the genus,B. izecksohni, and both names refer to the herpetologistEugênio Izecksohn.[4] "Flea-frog" or "flea-toad" was historically restricted toB. didactylus, once placed in its own genusPsyllophryne instead ofBrachycephalus, but a second species,B. hermogenesi, was described in 1998 and two others,B. pulex andB. sulfuratus, have been described since then, bringing it to four species of flea-frogs/toads.[5]
At 8.6–10.2 mm (0.34–0.40 in) in snout–to–vent length,[6]B. didactylus is one of thesmallest frogs in the world. This species and the roughly similar-sizedEleutherodactylus iberia from Cuba were once regarded asthe smallest,[7] but several others that are smaller have since been discovered, including the closely relatedB. pulex at 8–8.4 mm (0.31–0.33 in),[6]Stumpffia contumelia from Madagascar at 8–9 mm (0.31–0.35 in),[8] andPaedophryne amauensis from New Guinea at 7–8 mm (0.28–0.31 in).[9]
A relative comparison of some of the world's smallest frogs
^abIzecksohn, E. (1971). "Novo genero e novo especie de Brachycephalidae do estado do Rio de Janeiro, Brasil (Amphibia: Anura)".Boletim do Museu Nacional. Nova Serie, Zoologia.280:1–12.
^abcFrost, Darrel R. (2018)."Brachycephalus didactylus (Izecksohn, 1971)".Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved1 May 2018.
^Ribeiro, L.F.; Alves, A.C.R.; Haddad, C.F.B.; Dos Reis, S.F. (2005). "Two new species of Brachycephalus Günther, 1858 from the State of Paraná, southern Brazil (Amphibia, Anura, Brachycephalidae)".Bol. Mus. Nac. Rio J. Zool.519:1–18.
^Condez, T.H.; Monteiro, J.P.D.; Comitti, E.J.; Garcia, P.C.A.; Amaral, I.B.; Haddad, C.F.B. (2016). "A new species of flea-toad (Anura: Brachycephalidae) from southern Atlantic Forest, Brazil".Zootaxa.4083 (1):40–56.doi:10.11646/zootaxa.4083.1.2.PMID27394218.
^Zweifel, Richard G. (1998). Cogger, H.G.; Zweifel, R.G. (eds.).Encyclopedia of Reptiles and Amphibians. San Diego: Academic Press. p. 103.ISBN0-12-178560-2.
