Accepted by S. Castroviejo-Fisher: 16 Jan. 2014; published: 25 Feb. 2014 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2014 Magnolia Press Zootaxa 3768 (2): 159–177 www.mapress.com/zootaxa/ Article 159 http://dx.doi.org/10.11646/zootaxa.3768.2.4 http://zoobank.org/urn:lsid:zoobank.org:pub:FA258098-7021-40F7-B341-D339DE5C0EA6 Cryptic species diversity in marsupial frogs (Anura: Hemiphractidae: Gastrotheca) in the Andes of northern Peru WILLIAM E. DUELLMAN 1,3 , ANTHONY J. BARLEY 1 & PABLO J. VENEGAS 2 1 Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045-7561 USA 2 División de Herpetología, Centro de Ornitolgía y Biodiversidad, Santa Rita N o 20 Of. 202, Urb. Huertos de San Antonio, Surco, Lima, Perú 3 Corresponding author. E-mail: duellman@ku.edu Abstract Molecular phylogenetic analysis revealed the existence of two undescribed species of the hemiphractid genus Gastrotheca in the Andes in northern Peru. Both species are similar morphologically to Gastrotheca dysprosita and G. monticola, but they differ from these species and from one another in subtleties of coloration and minor variances in size and proportions. Gastrotheca aguaruna sp. nov. (6˚10'50"S, 77˚37'01"W, 2480 m) is from humid forested areas in the northern part of the Cordillera Central, whereas G. aratia sp. nov. (6˚14'00"S, 78˚51'24"W, 2560 m ) is known from the northern part of the Cordillera Occidental. Key words: Anura, Hemiphractidae, Gastrotheca, new species, phylogenetic relationships Resumen Un análisis filogenético molecular reveló la existencia de dos especies no descritas de hemiphráctidos del género Gas- trotheca en los Andes del norte de Perú. Ambas especies son morfológicamente similares a Gastrotheca dysprosita y G. monticola, pero se diferencian de estas y entre ellas por sutilezas en la coloración y variaciones menores en tamaño y proporciones. Gastrotheca aguaruna sp. nov. (6˚10'50"S, 77˚37'01"O, 2480 m) proviene de los bosques húmedos de la zona norte de la Cordillera Central, mientras que G. aratia sp. nov. (6˚14'00"S, 78˚51'24"O, 2560 m) es conocida de la zona norte de la Cordillera Occidental. Palabras claves: Anura, Hemiphractidae, Gastrotheca, nuevas especies, relaciones filogenéticas Introduction Analyses of molecular data have revealed novel phylogenetic relationships that have been proposed for many groups of anurans, viz.: terraranan frogs by Hedges et al. (2008), glass frogs of the family Centrolenidae by Guayasamin et al. (2009), and phyllomedusine hylids by Faivovich et al. (2010). Phylogeographic studies of molecular data have revealed significant biogeographic results, as demonstrated for groups of African frogs (e.g., Blackburn 2008; van der Meijden et al. 2005). On a finer scale, analyses of mitochondrial and nuclear genes have shown the existence of so-called cryptic species. Taxonomy supported by these phylogeographic studies has greatly heightened the number of known species of anurans, especially in the neotropics (e.g., Köhler et al. 2010; Coloma et al. 2012). Collections of frogs made in the Andes in northern Peru in 1979 and 1989 by Duellman and his field companions contained numerous specimens that were referred to Gastrotheca monticola Barbour and Noble. These frogs displayed considerable variation in color pattern and few differences in morphology. Consequently, all were considered to belong to a single species. Subsequently, Venegas collected additional specimens in northern Peru