Taxonomic Review of Allobates (Anura, Aromobatidae) from the Atlantic Forest, Brazil VANESSA K. VERDADE 1 AND MIGUEL T. RODRIGUES Departamento de Zoologia, Instituto de Biocie ˆncias, Universidade de Sa ˜o Paulo, Caixa Postal 11461, CEP 05422–970, Sa ˜o Paulo, Brazil ABSTRACT.—We present the results of a taxonomic review of the four species of Allobates endemic to the Atlantic Forest Domain in Brazil. A total of 880 preserved specimens from 29 localities covering their range in Atlantic Forest were studied based on external attributes. Characters formerly described as diagnostic in original descriptions and others cited for dendrobatids in the literature were studied along the total geographic range of the populations of these species, including the type localities. We found no discrete characters, qualitative or quantitative, capable of differentiating the species. Most local and geographic variation was limited to snout-vent length and color pattern. Considering the lack of evidence otherwise, we use the results of our morphological analysis to allocate all Atlantic Forest species of Allobates to synonymy with Allobates olfersioides. Dendrobatids are a monophyletic group of frogs that are mostly known for their bright color and poisonous skin. Nevertheless, about half of the species are cryptically and dull colored, presumably nontoxic and until recently (Grant et al., 2006) placed in the genus Colos- tethus sensu lato. There had been about a hun- dred recognized species in the genus ranging from Nicaragua to southeastern Brazil (Frost, 2006). The systematics of the family has recently gone through significant changes (Grant et al., 2006) supported by a molecular and morpho- logical based phylogeny. The family Dendroba- tidae, as previously known, corresponds now to Dendrobatoidea, which includes the families Aromobatidae and Dendrobatidae. The four species of Colostethus from Atlantic Forest, now allocated to the genus Allobates, are placed in the family Aromobatidae. The Brazilian species of Allobates are leaf litter inhabitants of forests and can be found through- out the Amazon Basin, Brazilian Savannas, and Atlantic Forest. Most of the 17 currently recognized species are Amazonian and de- scribed recently, probably as a consequence of a vast and poorly sampled territory along with increased knowledge of the natural history of these frogs (e.g., Morales, 2000; Lima and Caldwell, 2001; Caldwell and Lima, 2003). There are four species in eastern Brazil, endemic to the Atlantic Forest Domain (Ab’Saber, 1977): Allo- bates alagoanus (Bokermann, 1967), Allobates capixaba (Bokermann, 1967), Allobates carioca (Bokermann, 1967), and Allobates olfersioides (Lutz, 1925). Allobates olfersioides was described as Eupem- phix olfersioides Lutz, 1925 from the coastal region of the state of Rio de Janeiro (RJ). Cochran (1955) considered it a synonym of Phyllobates brunneus Cope, 1887. Bokermann (1966) restricted the type locality of A. olfer- sioides to Angra dos Reis (RJ) and, in 1967, described the other three Atlantic Forest species: Phyllobates alagoanus from Usina Sinimbu, Man- gabeiras, state of Alagoas; Phyllobates capixaba from Lagoa do Macuco, Refu ´ gio Sooretama, Linhares, state of Espı ´rito Santo; and Phyllobates carioca from Represa Rio Grande, Jacarepagua ´, Rio de Janeiro, state of Rio de Janeiro. Boker- mann (1967) also considered P. olfersioides re- lated to P. alagoanus, P. capixaba and P. carioca. Edwards (1974) placed these four species in Colostethus, as did Silverstone (1975). Grant et al. (2006) based on an extensive sampling and molecular plus morphological based phylogeny allocated them to the genus Allobates. The four species are very similar in external attributes and were described based on small and geographically remote samples. The char- acters used by Bokermann (1967) to separate these species were basically color pattern, length of limbs and fingers, size of carpal and tarsal tubercles, shape of head, and snout-vent length. All of these characters are presumably subject to geographical variation, a possibility that could not be tested at that time. Bokermann (1967) also presented information on call variation, pointing out that the calls of A. capixaba and A. carioca were distinct from that of A. olfersioides, but, except for saying that the call of A. capixaba was more spaced than those of A. olfersioides, no further description was given. Besides, the putative call differences between 1 Corresponding Author. E–mail: vverdade@usp.br Journal of Herpetology, Vol. 41, No. 4, pp. 566–580, 2007 Copyright 2007 Society for the Study of Amphibians and Reptiles