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The status of Elachistocleis pearsei, E. surinamensis, E. sikuani and E. tinigua Elachistocleissurinamensis and E. pearsei aretheoldest available names in this group. The former was named by Daudin (1802) as Bufo surinamensis, and the latter was named by Ruthven (1914) as Hypopachus pearsei. Both were considered synonyms of Elachistocleis ovalis by Parker (1934). Dunn (1944; 1949) commented on H. pearsei under the new combination Elachistocleis pearsei. Carvalho (1954) placed it into the new genus Relictivomer Carvalho, 1954 based on the presence of the posterior part of the prevomer and, recently, de Sá et al. (2012) reallocated it into Elachistocleis based on DNA data. Kenny (1969) redescribed E. surinamensis from specimens from Trinidad and cited a personal communication from A. Grandison, who had found no differences between specimens of E. surinamensis from Trinidad and a paratype of E. pearsei. Duellman (1997) also compared specimens of E. pearsei from Panama and specimens of Elachistocleis sp. from Gran Sabana, south-eastern Venezuela (which he did not assign to any species, but which falls in the range of occurrence of E. surinamensis; see Fig. 3) and did not find any noticeable difference in the external morphology of adults or in their advertisement calls. Jowers et al. (2021) recently redescribed and designated a neotype for E. surinamensis from Trinidad but, unfortunately, provided no comparisons of the species with E. pearsei. While the present paper was in review, two new species from Colombia were described and named: Elachistocleis sikuani and E. tinigua (AcostaGalvis et al., 2022). Although we did not access the vouchers and did not include the new sequences generated therein in our analyses, we confirmed that two lineages already represented in our tree correspond to them (based on genetic similarity, 99.8%). The authors made a brief comparison of the new species with E. pearsei and E. surinamensis, mentioning some differences in body size, quantity and colour of the blotches in live specimens, degree of conspicuousness of the post-commissural glands and presence/absence of the mid-dorsal white line (Acosta-Galvis et al., 2022). The latter feature was reported as absent in E. sikuani and E. tinigua but present (‘evident’) in E. surinamensis. However, as mentioned above in discussion about the variation of E. surumu, the presence of a mid-dorsal white line in E. surinamensis was not reported in its original description (see: Daudin, 1802) or in its redescription and neotype designation (see: Jowers et al., 2021). On the contrary, Jowers et al. (2021) used the absence of the mid-dorsal line in E. surinamensis to distinguish it from E. nigrogularis. We also have not observed a mid-dorsal white line in any examined specimens of E. surinamensis (Fig. 1). Acosta-Galvis et al. (2022) did not provide a comparison between E. pearsei and E. surinamensis. Instead, they added more pieces to the puzzle by giving new names to two allopatric lineages. They followed the prevailing tradition in the taxonomy of Elachistocleis of creating more and more nomina rather than conducting a thorough review addressing the validity and application of available names. We reiterate that a comprehensive morphological revision of Elachistocleis is needed and should take priority over the naming of additional new Elachistocleis species. Unfortunately, our sampling of specimens of those species is limited, and a reassessment of the taxonomic status of those species is beyond the scope of the present work. Therefore, for time being, we recognize E. pearsei, E. surinamensis, E. sikuani and E. tinigua as valid species., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on page 560, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Daudin FM. 1802. Histoire naturelle des rainettes, des grenouilles et des crapauds. Paris: Levrault.","Ruthven AG. 1914. Description of a new engystomatid frog of the genus Hypopachus. Proceedings of the Biological Society of Washington 27: 77 - 80.","Parker H. 1934. A monograph of the frogs of the family Microhylidae. London: Trustees of the British Museum.","Dunn ER. 1944. Los generos de anfibios y reptiles de Colombia, 1. Primera parte: anfibios. Caldasia 2: 497 - 529.","Dunn ER. 1949. Notes on South American frogs of the family Microhylidae. American Museum NoVitates 1419: 1 - 21.","de Carvalho AL. 1954. A preliminary synopsis of the genera of American microhylid frogs. Occasional Papers of the Museum of Zoology. UniVersity of Michigan 555: 1 - 22.","de Sa RO, Streicher JW, Sekonyela R, Forlani MC, Loader SP, Greenbaum E, Richards S, Haddad CFB. 2012. Molecular phylogeny of microhylid frogs (Anura: Microhylidae) with emphasis on relationships among New World genera. BMC EVolutionary Biology 12: 241.","Kenny JS. 1969. The amphibia of Trinidad. Studies on the fauna of Curacao and other Caribbean islands 108: 1 - 78.","Duellman WE. 1997. Amphibians of La Escalera region, southeastern Venezuela: taxonomy, ecology, and biogeography. Scientific Papers Natural History Museum the UniVersity of Kansas 2: 1 - 52.","Jowers MJ, Othman SN, Borzee A, Rivas GA, Sanchez- Ramirez S, Auguste RJ, Downie JR, Read M, Murphy JC. 2021. Unraveling unique island colonization events in Elachistocleis frogs: phylogeography, cryptic divergence, and taxonomical implications. Organisms DiVersity & EVolution 21: 189 - 206.","Acosta-Galvis AR, Tonini JFR, de Sa RO. 2022. Two new species of Elachistocleis Parker, 1927 (Anura: Microhylidae: Gastrophryninae) from Colombia. Zootaxa 5099: 527 - 548."]}

Elachistocleis surumu Caramaschi, 2010 as a junior subjective synonym of Elachistocleis surinamensis (Daudin, 1802) Although we do not have samples from the type locality of E. surumu (Vila Surumu, Municipality of Pacaraima, State of Roraima, Brazil), we sampled many specimens from nearby localities surrounding the type locality (Fig. 3) and all of them are recovered in a single lineage that is widespread in the eastern portion of the Guiana Shield (Figs 1, 3). The proposed morphological differences between E. surumu and E. surinamensis are subtle. Caramaschi (2010) differentiated E. surumu from E. surinamensis based on the alleged presence of a light vertebral stripe in E. surinamensis (absent in E. surumu) and minor details in the ventral colour patterns. However, neither the original description of E. surinamensis (Daudin, 1802) nor the recent species redescription and neotype designation (Jowers et al., 2021) stated that E. surinamensis has any kind of dorsal stripe or line. Caramaschi (2010) did not list any voucher specimens of E. surinamensis in his list of examined material. Ventral colour patterns of E. surumu are contained in the variation found herein for specimens of E. surinamensis (see also: Jowers et al., 2021). Therefore, we consider Elachistocleis surumu Caramaschi, 2010 as a junior subjective synonym of Elachistocleis surinamensis (Daudin, 1802)., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on page 558, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Caramaschi U. 2010. Notes on the taxonomic status of Elachistocleis oValis (Schneider, 1799) and description of five new species of Elachistocleis Parker, 1927 (Amphibia, Anura, Microhylidae). Boletim do Museu Nacional 527: 1 - 30.","Daudin FM. 1802. Histoire naturelle des rainettes, des grenouilles et des crapauds. Paris: Levrault.","Jowers MJ, Othman SN, Borzee A, Rivas GA, Sanchez- Ramirez S, Auguste RJ, Downie JR, Read M, Murphy JC. 2021. Unraveling unique island colonization events in Elachistocleis frogs: phylogeography, cryptic divergence, and taxonomical implications. Organisms DiVersity & EVolution 21: 189 - 206."]}

THE ELACHISTOCLEIS BICOLOR GROUP We recognize four nominal species in the E. bicolor group: E. bicolor, E. haroi, E. helianneae and E. nigrogularis. Except for E. nigrogularis, species of this group predominantly have an immaculate belly, but see comments below., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on page 557, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481

Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill, Peloso, Pedro (2023): A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis). Zoological Journal of the Linnean Society 197: 545-568, DOI: 10.1093/zoolinnean/zlac057

The (unsettling) status of Elachistocleis ovalis There has been a long controversy regarding the validity and applicability of this nomen, especially regarding whether it should be applied to immaculate or to maculate-bellied specimens of Elachistocleis [see Lavilla et al. (2003) and Caramaschi (2010) for lengthy discussions on the issue]. While some authors (e.g. Parker, 1927; Dunn, 1949; Kenny, 1969; De la Riva et al., 2000) applied this name to maculate-bellied specimens – thus conveniently distinguishing them from the immaculate-bellied E. bicolor – others did not. In a meeting abstract of his unpublished dissertation, Carcerelli (1992) regarded E. bicolor a junior synonym of E. ovalis; a view that was followed by a few other authors (e.g. Klappenbach & Langone, 1992; Olmos & Achaval, 1997; Kwet & Di-Bernardo, 1998). That decision was mainly grounded on the fact that Schneider (1799) stated that Rana ovalis had an ‘ inferne flavidus ’ (yellow venter). Lavilla et al. (2003) also remarked that, considering Schneider’s description, E. ovalis should be applied to the specimens with ‘immaculate, yellow, ventral colouration’; but they did not adhere to the idea of synonymizing E. ovalis and E. bicolor. Instead, they regarded E. ovalis as restricted to the ‘northern portion of the generic range’, whereas E. bicolor would be restricted to the ‘southern portion of the generic range’. Nevertheless, ventral patterns have been recorded idiosyncratically in the literature and ‘uniform’, ‘yellow’ and ‘immaculate’ bellies have often been treated as synonyms, although this is not necessarily the case. Some individuals of typically maculatebellied species can present the venter almost entirely covered by yellow blotches (e.g. Fig. 5G, J, L) and thus could also fit into the ‘ inferne flavidus ’ description. Thus, assuming that the type of E. ovalis had an immaculate venter, because Schneider (1799) stated that it has ‘ inferne flavidus ’, is not solid reasoning in itself. Moreover, as described above for our samples from Cuiabá (AAG-UFU 5953 and AAG-UFU 5954), sympatric specimens may present different ventral patterns and still be genetically similar, increasing the complexity of this puzzle. The identity of E. ovalis is still a conundrum, especially difficult to solve due to the lack of a type locality and the unknown whereabouts of the type specimen. For these reasons, among others, Caramaschi (2010) proposed an operational solution: he considered Rana ovalis Schneider, 1799 and the combination Elachistocleis ovalis a nomen dubium associated with a species inquirenda; a decision that was followed by Jowers et al. (2021). Since we could not find any new evidence on the contrary, we also adhere to that decision by Caramaschi (2010). AmphibiaWeb (2022) and Frost (2022), the two largest amphibian taxonomic catalogues, have essentially also followed this suggestion and, although both still include this species in their list of 22 recognized Elachistocleis species, the following notes are added for E. ovalis: ‘Nominally, Elachistocleis ovalis is a nomen inquirenda (see comment), not applied to a biological population. But, pending revision, this name is applied to populations from Bolivia, although a great deal of confusion surrounds the identification of specimens mentioned from other countries’ (Frost, 2022); ‘This ancient name (1799) lacks type material and there is no type locality. Despite wide usage it should be considered an invalid name and not used [...] Pending revision, AmphibiaWeb continues to use the name E. ovalis ’ (AmphibiaWeb, 2022)., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on pages 561-562, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Lavilla EO, Vaira M, Ferrari L. 2003. A new species of Elachistocleis (Anura: Microhylidae) from the Andean Yungas of Argentina, with comments on the Elachistocleis oValis - E. bicolor controversy. Amphibia-Reptilia 24: 269 - 284.","Caramaschi U. 2010. Notes on the taxonomic status of Elachistocleis oValis (Schneider, 1799) and description of five new species of Elachistocleis Parker, 1927 (Amphibia, Anura, Microhylidae). Boletim do Museu Nacional 527: 1 - 30.","Parker HW. 1927. The brevicipitid frogs allied to the genus Gastrophryne. Occasional Papers of the Museum of Zoology. UniVersity of Michigan 187: 1 - 6.","Dunn ER. 1949. Notes on South American frogs of the family Microhylidae. American Museum NoVitates 1419: 1 - 21.","Kenny JS. 1969. The amphibia of Trinidad. Studies on the fauna of Curacao and other Caribbean islands 108: 1 - 78.","De la Riva I, Kohler J, Lotters S, Reichle S. 2000. Ten years of research on Bolivian amphibians: updated checklist, distribution, taxonomic problems, literature and iconography. ReVista Espanola de Herpetologia 14: 19 - 164.","Klappenbach MA, Langone JA. 1992. Lista sistematica y sinonimica de los anfibios del Uruguay con comentarios y notas sobre su distribucion. Anales del Museo Nacional de Historia Natural de MonteVideo (2. a Serie) 8: 163 - 222.","Olmos A, Achaval F. 1997. Anfibios y reptiles del Uruguay. Montevideo: Barreiro y Ramos.","Kwet A, Di-Bernardo M. 1998. Elachistocleis erythrogaster, a new microhylid species from Rio Grande do Sul, Brazil. Studies on Neotropical Fauna and EnVironment 33: 7 - 18.","Schneider JG. 1799. Historia amphibiorum naturalis et literarariae. Fasciculus primus. Continens ranas, calamitas, bufones, salamandras et hydros in genera et species descriptos notisque suis distinctos. Jena: Friederici Frommanni.","Jowers MJ, Othman SN, Borzee A, Rivas GA, Sanchez- Ramirez S, Auguste RJ, Downie JR, Read M, Murphy JC. 2021. Unraveling unique island colonization events in Elachistocleis frogs: phylogeography, cryptic divergence, and taxonomical implications. Organisms DiVersity & EVolution 21: 189 - 206.","Frost DR. 2022. Amphibian species of the aeorld: an online reference, V. 6.1. New York: American Museum of Natural History. Doi: 10.5531 / db. vz. 0001. Electronic database available at https: // amphibiansoftheworld. amnh. org / index. php (accessed 2 April 2022)."]}

The status of Elachistocleis cesarii, E. piauiensis and E. magna Miranda-Ribeiro (1920) described two subspecies of Engystoma ovale based on maculate-bellied specimens from the state of São Paulo, Brazil, which were later synonymized by Parker (1934) with Elachistocleis ovalis. Toledo et al. (2010) recently resurrected and redescribed them under the new combination Elachistocleis cesarii. Herein we recognize E. cesarii as a species distributed in south-eastern and central-western Brazil (Fig. 3) and closely related to E. piauiensis and E. magna (Fig. 1). Elachistocleis piauiensis was described and named by Caramaschi & Jim (1983) from Picos, Piauí. We found four lineages distributed in north-eastern Brazil, but we could not confidently assign any to E. piauiensis, because we did not have access to data from the type locality. Specimens assigned to each of these four lineages are morphologically similar to each other and to the original species description of E. piauiensis. The ventral colour pattern varies widely and similarly along the clade composed of E. cesarii, E. magna and the four candidate species E. cf. piauiensis 1–4, with no clear difference between them. The presence/absence of the mid-dorsal line also varies, except for E. cf. piauiensis 3, in which all examined vouchers lack the line. The holotype of E. piauiensis also lacks the line, and this could be evidence to assign the name to this specific clade. However, we cannot rule out that the consistent absence in E. cf. piauiensis 3 is not an effect of our sampling, given the high variability of this character state in several of our delimited species (Fig. 1). Elachistocleis cesarii was distinguished from E. piauiensis by differences in the advertisement call, size of the post-commissural gland and details of the inguinal region colouration (Toledo et al., 2010) – phenotypic traits that we have not explored for the present contribution. On the other hand, E. magna was distinguished from E. cesarii and E. piauiensis solely by its size (male SVL above 31 mm in E. magna, against SVL below 29 mm in E. cesarii and E. piauiensis; Toledo, 2010). Among examined specimens, we observed a consistent difference in size between E. magna and E. cf. piauiensis 1–4, but not between E. magna and E. cesarii. Males of E. cesarii can have SVL up to 31 mm, whereas some males of E. magna have SVL below 29 mm. Therefore, a thorough evaluation of phenotypic data allied with a denser molecular sampling is needed to verify if the differential diagnoses among E. cesarii, E. piauiensis and E. magna will hold true with additional data., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on pages 560-561, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Miranda-Ribeiro A. 1920. Os engystomatideos do Museu Paulista (com um genero e tres especies novos). ReVista do Museu Paulista. Sao Paulo 12: 281 - 288.","Parker H. 1934. A monograph of the frogs of the family Microhylidae. London: Trustees of the British Museum.","Toledo LF, Loebmann D, Haddad CFB. 2010. Revalidation and redescription of Elachistocleis cesarii (Miranda-Ribeiro, 1920) (Anura: Microhylidae). Zootaxa 2418: 50 - 60.","Caramaschi U, Jim J. 1983. A new microhylid frog, genus Elachistocleis (Amphibia, Anura), from northeastern Brasil. Herpetologica 39: 390 - 394."]}

The (mysterious) status of Elachistocleis corumbaensis Unfortunately, we have no samples confidently assignable to E. corumbaensis. We have two samples from two localities near (around 20 km and 80 km) but not from the type locality of the species (Parque Municipal de Piraputangas, Corumbá municipality; Piva et al., 2017) (Fig. 3). For one of these tissue samples (CFBHT 00078), we were unable to find the voucher specimen. The other (MAPT 1363) was identified by the collectors as E. matogrosso (see: Koroiva et al., 2020). So we assume, albeit tentatively, that it has an immaculate venter. Both samples fall with E. bicolor in our species delimitation (Fig. 1). However, E. corumbaensis was described as having a maculate belly (Piva et al., 2017). The closest locality that we have a sample of a maculate-bellied species (E. cesarii) is Campo Grande, state of Mato Grosso do Sul, Brazil, 357 km from the type locality of E. corumbaensis. It is also worth remarking that E. corumbaensis has several similarities with E. haroi, particularly the dorsal pattern with a dark mark in the shape of a pine tree (Pereyra et al., 2013; Piva et al., 2017). Our closest sample of E. haroi is from Puerto Carmelo Peralta, Department of Alto Paraguay (Paraguay), 275 km south of the type locality of E. corumbaensis. For the moment, we consider E. corumbaensis a valid species, although it is unclear if this species belongs to the E. bicolor group or to the E. surinamensis group. The (unresolved) status of Elachistocleis erythrogaster This species is apparently restricted to the Centre of Research and Nature Conservation Pró-Mata, state of Rio Grande do Sul, above 900 m a.s.l. (Kwet & Di-Bernardo, 1998). It was distinguished from E. bicolor [treated as E. ovalis in Kwet & Di-Bernardo (1998)], which occurs in sympatry, by the unique red belly, larger size and other bioacoustic and reproductive characteristics (Kwet & Di-Bernardo, 1998). We have sampled some individuals from localities close to the type locality – although from the lowland – and they all fall with E. bicolor. This species has not been collected for nearly 20 years and is considered to be rare (Kwet et al., 2010)., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on page 561, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Piva A, Caramaschi U, Albuquerque NR. 2017. A new species of Elachistocleis (Anura: Microhylidae) from the Brazilian Pantanal. Phyllomedusa. Journal of Herpetology 16: 143 - 154.","Koroiva R, Rodrigues LRR, Santana DJ. 2020. DNA barcoding for identification of anuran species in the central region of South America. PeerJ 8: e 10189.","Pereyra LC, Akmentins MS, Laufer G, Vaira M. 2013. A new species of Elachistocleis (Anura: Microhylidae) from north-western Argentina. Zootaxa 3694: 525 - 544.","Kwet A, Di-Bernardo M. 1998. Elachistocleis erythrogaster, a new microhylid species from Rio Grande do Sul, Brazil. Studies on Neotropical Fauna and EnVironment 33: 7 - 18.","Kwet A, Lingnau R, Di-Bernardo M. 2010. Pro-Mata: anfibios da Serra Gaucha, sul do Brasil - Amphibien der Serra Gaucha, Sudbrasilien - amphibians of the Serra Gaucha, south of Brazil. Tubingen and Porto Alegre: Brasilien-Zentrum de Universitat Tubingen and EDIPUCRS."]}

Elachistocleis bumbameuboi Caramaschi, 2010 and Elachistocleis carvalhoi Caramaschi, 2010 as junior subjective synonyms of Elachistocleis magna Toledo, 2010 Caramaschi (2010) distinguished E. bumbameuboi and E. carvalhoi from E. magna based on subtle differences in the dorsal and ventral colour patterns, as follows: regarding the dorsal pattern, E. magna has ‘dorsum uniform dark greyish with scarce minute brighter dots in the outer boundaries’, whereas E. bumbameuboi and E. carvalhoi have, respectively, ‘dorsum uniformly dark grey or black without marks’ and ‘dorsum uniformly brown or dark grey without marks’; regarding the ventral pattern, E. magna has ‘venter grey with minute scattered white spots, mainly on the belly and ventral surfaces of legs’, whereas E. bumbameuboi and E. carvalhoi have, respectively, ‘venter grey with minute anastomosed whitish spots, producing a salt-and-pepper pattern’ and ‘venter greyish with large anastomosed yellow or whitish yellow blotches, producing a coarse marbled pattern, mainly in the chest area. Photographs of the holotypes of E. carvalhoi (Caramaschi, 2010: fig. 3) and E. bumbameuboi (Caramaschi, 2010: fig. 4) and a photograph of a paratype of E. bumbameuboi (Nunes et al., 2010: fig. 1) depict specimens with dorsa scattered with minute white dots. Thus, our examination of specimens of E. bumbameuboi, E. carvalhoi and E. magna show a broad overlap among the various shades of dorsal colour and the size and distribution pattern of ventral markings (e.g. see Fig. 5). Based on our phylogenetic hypothesis, on the broad geographic sampling, which included a paratype of E. bumbameuboi, topotypes of E. carvalhoi and E. magna, and on the examination of several voucher specimens, we consider that E. bumbameuboi Caramaschi, 2010 and E. carvalhoi Caramaschi, 2010 are junior subjective synonyms of E. magna Toledo, 2010., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on pages 558-560, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Caramaschi U. 2010. Notes on the taxonomic status of Elachistocleis oValis (Schneider, 1799) and description of five new species of Elachistocleis Parker, 1927 (Amphibia, Anura, Microhylidae). Boletim do Museu Nacional 527: 1 - 30.","Nunes I, Canedo C, Carvalho RR. 2010. Advertisement call and geographic distribution of Elachistocleis piauiensis Caramaschi & Jim, 1983 (Amphibia, Microhylidae), with notes on the presence of post-commissural gland in the genus. South American Journal of Herpetology 5: 30 - 34."]}

TAXONOMY OF ELACHISTOCLEIS – A COMPLEX MATTER Parker (1927) erected Elachistocleis to allocate Rana ovalis Schneider, 1799 and Engystoma ovale bicolor (Guérin-Méneville, 1838). As usual at the time, the descriptions of both species were brief and did not designate type specimens. Lavilla et al. (2003) suggested that these names apply to complexes of species, because species of this genus are morphologically similar, with few obvious external characters that can be used as reliable diagnostic characters (i.e. non-overlapping and fixed). Ultimately, as mentioned throughout our contribution, diagnoses in this genus rely heavily on the ventral colour pattern, head proportions and the presence/absence and extension of body lines, such as a mid-dorsal white line and lines on the hidden surface of hindlimbs (Parker, 1927; Lavilla et al., 2003; Caramaschi, 2010; Pereyra et al., 2013). Caramaschi (2010) and Piva et al. (2017) suggested the ventral colour pattern as a diagnostic character for two internal species groups: a group with immaculate bellies (uniformly clear, free of markings) and another with maculate bellies. We found that the groups proposed by the above-cited authors are not monophyletic. For example, Elachistocleis muiraquitan (immaculate-bellied) is not related to the remaining immaculate-bellied species; instead, it was recovered in the E. surinamensis species group, a clade composed of species with predominantly maculate bellies. Furthermore, whereas E. panamensis has a maculate belly (Dunn et al., 1948; Nelson, 1972), E. araios has an immaculate belly (Sánchez-Nivicela et al., 2020). Given their phylogenetic position as successive sistertaxa to the remaining species of the genus (but see our comments on the position of E. araios), the description of E. araios already rendered the immaculate-bellied species group as paraphyletic. Also, it implies that the optimization of the ventral pattern of the Elachistocleis ancestor is ambiguous, given our topology and that of Sánchez-Nivicela et al. (2020). More importantly, we found intraspecific variation of the ventral pattern in some species, such as E. bicolor and E. nigrogularis (Figs 1, 4). Ontogenetic variation of the ventral pattern has also been recently reported for E. haroi (Bueno-Villafañe et al., 2020). Therefore, the available phylogenetic and morphological evidence emphatically rejects the existence of groups diagnosed solely by the colour of their bellies. It is noteworthy that this discussion seems far from settled. Ventral patterns have been recorded idiosyncratically in the literature. Sánchez-Nivicela et al. (2020) cite E. cesarii as ‘having uniform, immaculate, ventral colouration’, although Toledo et al. (2010) when resurrecting the species clearly state that it has ‘ventral colouration white or yellow with grey marks and reticulations’, and their figure 3d depicts a specimen with a maculate belly. Jowers et al. (2021) state that E. cesarii has a ‘uniform’ belly. This same was said of E. erythrogaster and E. bicolor. While E. cesarii and E. erythrogaster are maculate (the latter comparatively less maculate), E. bicolor bellies usually present no markings whatsoever (but see discussion on E. bicolor below). Given the historical use of the ventral pattern in the taxonomy of Elachistocleis, we attempted to verify as many specimens as possible for this trait. We have not extensively checked our vouchers for other morphological diagnostic traits (male throat colour; presence and shape of the femoral stripe; post-commissural gland). Nevertheless, our preliminary data suggest that none of the above-cited morphological traits is as reliable as suggested in the literature [see also comments in Nunes et al. (2010) and Marinho et al. (2018)]. Data from other sources are scarce. Tadpoles of few species are described (e.g. Rossa-Feres & Nomura, 2006; Pereyra et al., 2013; Schulze et al., 2015; Ferreira & Weber, 2021), but it is difficult to confidently assign these descriptions to lineages recovered because most lack an association with available DNA sequences. Moreover, there is no comprehensive understanding of variation, although Gómez & Kehr (2012) reported some variability in larval morphology related to chemical cues in the presence of predators. Advertisement calls of several Elachistocleis have been described (e.g. Nelson, 1972; Duellman, 1997; Kwet & Di-Bernardo, 1998; Lavilla et al., 2003; Nunes et al., 2010; Toledo, 2010; Marinho et al., 2018; Pansonato et al., 2018; Jowers et al., 2021). Some of these are associated with vouchers present in our phylogeny (see: Marinho et al., 2018; Jowers et al., 2021). These are not adequately distributed in our topology and most are described from a few specimens and localities. Published data have already shown that even slight increases in sample size may affect recorded variation (see: Marinho et al., 2018). Finally, some localities present at least two sympatric species of Elachistocleis. For instance, both E. nigrogularis and E. surinamensis are syntopically found at the type locality of E. nigrogularis (Jowers et al., 2021), and both E. bicolor and E. erythrogaster are found at the type locality of E. erythrogaster (Kwet & Di-Bernardo, 1998) (also see Fig. 3). This makes it even more difficult to associate larvae with adults and advertisement calls of unvouchered specimens to named species without molecular data. A fine line A white or light yellow mid-dorsal line is present in many individuals of Elachistocleis, and other genera of Gastrophryninae, such as Chiasmocleis Méhelÿ, 1904 (e.g. Peloso et al., 2014), Ctenophryne Mocquard, 1904 (e.g. Duellman, 1978), Hamptophryne A.L. Carvalho, 1954 (e.g. Parker, 1927; Duellman, 1978), Hypopachus [e.g. Cope (1889); see also figure 5 in Greenbaum et al. (2011)], Dasypops Miranda-Ribeiro, 1924 and Stereocyclops Cope, 1870 (PP, personal observation). Many authors have noticed important intraspecific or intrapopulational variation (i.e. being present in some individuals and absent in others) in this character in other genera (e.g. Chiasmocleis, Peloso et al., 2014; Ctenophryne, Zweifel & Myers, 1989; Stereocyclops, GNF, personal observation) and in Elachistocleis (e.g. Nelson, 1972; Toledo, 2010; Toledo et al., 2010; Marinho et al., 2018). Notwithstanding, the occurrence of this line and the variation of its extension when present (e.g. from snout to vent or from post-cephalic fold to vent) were used in diagnoses of several Elachistocleis species (e.g. Caramaschi & Jim, 1983; Caramaschi, 2010; Nunes-de-Almeida & Toledo, 2012; Piva et al., 2017). We found a remarkable variation in the occurrence of the mid-dorsal white line in and among species (Fig. 1), similar to the variation reported for Chiasmocleis (Peloso et al., 2014). This variation challenges the reliability of the trait as a diagnostic feature and weakens the known diagnoses of several currently recognized species (see below). It was impossible to confidently evaluate the extension of the mid-dorsal line, thus we only scored the presence or the absence of the line. Hence, we recommend caution when using the mid-dorsal line in the systematics of Elachistocleis, especially for diagnostic purposes., Published as part of Novaes-E-Fagundes, Gabriel, Lyra, Mariana L., Loredam, Vinicius S. A., Carvalho, Thiago R., Haddad, Célio F. B., Rodrigues, Miguel T., Baldo, Diego, Barrasso, Diego A., Loebmann, Daniel, Ávila, Robson W., Brusquetti, Francisco, Prudente, Ana L. C., Wheeler, Ward C., Orrico, Victor Goyannes Dill & Peloso, Pedro, 2023, A tale of two bellies: systematics of the oval frogs (Anura: Microhylidae: Elachistocleis), pp. 545-568 in Zoological Journal of the Linnean Society 197 on pages 554-555, DOI: 10.1093/zoolinnean/zlac057, http://zenodo.org/record/7695481, {"references":["Parker HW. 1927. The brevicipitid frogs allied to the genus Gastrophryne. Occasional Papers of the Museum of Zoology. UniVersity of Michigan 187: 1 - 6.","Schneider JG. 1799. Historia amphibiorum naturalis et literarariae. Fasciculus primus. Continens ranas, calamitas, bufones, salamandras et hydros in genera et species descriptos notisque suis distinctos. Jena: Friederici Frommanni.","Guerin-Meneville F-E. 1838. Iconographie du regne Animal de G. CuVier ou representation d'apres nature de l'une des especes les plus remarquables et souVent non enVore figurees, de chaque genre d'animaux, aVec un texte descriptiff mis au courant de la science, Vol. 3 (Part - Reptiles). Paris: J. B. Balliere.","Lavilla EO, Vaira M, Ferrari L. 2003. A new species of Elachistocleis (Anura: Microhylidae) from the Andean Yungas of Argentina, with comments on the Elachistocleis oValis - E. bicolor controversy. Amphibia-Reptilia 24: 269 - 284.","Caramaschi U. 2010. Notes on the taxonomic status of Elachistocleis oValis (Schneider, 1799) and description of five new species of Elachistocleis Parker, 1927 (Amphibia, Anura, Microhylidae). Boletim do Museu Nacional 527: 1 - 30.","Pereyra LC, Akmentins MS, Laufer G, Vaira M. 2013. A new species of Elachistocleis (Anura: Microhylidae) from north-western Argentina. Zootaxa 3694: 525 - 544.","Piva A, Caramaschi U, Albuquerque NR. 2017. A new species of Elachistocleis (Anura: Microhylidae) from the Brazilian Pantanal. Phyllomedusa. Journal of Herpetology 16: 143 - 154.","Dunn ER, Trapido H, Evans H. 1948. A new species of the microhylid frog genus Chiasmocleis from Panama. American Museum NoVitates 1376: 1 - 8.","Nelson CE. 1972. Distribution and biology of Chiasmocleis panamensis (Amphibia: Microhylidae). Copeia 1972: 895 - 898.","Sanchez-Nivicela JC, Peloso PLV, Urgiles VL, Yanez- Munoz MH, Sagredo Y, Paez N, Ron S. 2020. Description and phylogenetic relationships of a new trans-Andean species of Elachistocleis Parker 1927 (Amphibia, Anura, Microhylidae). Zootaxa 4779: 323 - 340.","Bueno-Villafane D, Caballlero-Gini A, Ferreira M, Netto F, Fernandez Rios D, Brusquetti F. 2020. Ontogenetic changes in the ventral colouration of post metamorphic Elachistocleis haroi Pereyra, Akmentins, Laufer, Vaira, 2013 (Anura: Microhylidae). Amphibia-Reptilia 41: 191 - 200.","Toledo LF, Loebmann D, Haddad CFB. 2010. Revalidation and redescription of Elachistocleis cesarii (Miranda-Ribeiro, 1920) (Anura: Microhylidae). Zootaxa 2418: 50 - 60.","Jowers MJ, Othman SN, Borzee A, Rivas GA, Sanchez- Ramirez S, Auguste RJ, Downie JR, Read M, Murphy JC. 2021. Unraveling unique island colonization events in Elachistocleis frogs: phylogeography, cryptic divergence, and taxonomical implications. Organisms DiVersity & EVolution 21: 189 - 206.","Nunes I, Canedo C, Carvalho RR. 2010. Advertisement call and geographic distribution of Elachistocleis piauiensis Caramaschi & Jim, 1983 (Amphibia, Microhylidae), with notes on the presence of post-commissural gland in the genus. South American Journal of Herpetology 5: 30 - 34.","Marinho P, Carvalho TR, Bang DL, Teixeira BFDV, Azarak PA, Campos CEC, Giaretta AA. 2018. Advertisement calls, intraspecific variation and species diagnosis of six Brazilian species of Elachistocleis (Anura: Microhylidae: Gastrophryninae). Zootaxa 4521: 357 - 375.","Rossa-Feres D de C, Nomura F. 2006. Characterization and taxonomic key for tadpoles (Amphibia: Anura) from the northwestern region of Sao Paulo State, Brazil. Biota Neotropica 6: 1 - 26.","Schulze A, Jansen M, Kohler G. 2015. Tadpole diversity of Bolivia's lowland anuran communities: molecular identification, morphological characterisation, and ecological assignment. Zootaxa 4016: 1 - 111.","Ferreira JS, Weber LN. 2021. A survey of the external morphology, internal oral morphology, chondrocranium and hyobranchial apparatus of Elachistocleis larvae Parker, 1927 (Anura, Microhylidae). Journal of Morphology 282: 472 - 484.","Gomez VI, Kehr AI. 2012. The effect of chemical signal of predatory fish and water bug on the morphology and development of Elachistocleis bicolor tadpoles (Anura: Microhylidae). Biologia 67: 1001 - 1006.","Duellman WE. 1997. Amphibians of La Escalera region, southeastern Venezuela: taxonomy, ecology, and biogeography. Scientific Papers Natural History Museum the UniVersity of Kansas 2: 1 - 52.","Kwet A, Di-Bernardo M. 1998. Elachistocleis erythrogaster, a new microhylid species from Rio Grande do Sul, Brazil. Studies on Neotropical Fauna and EnVironment 33: 7 - 18.","Pansonato A, Mudrek JR, Nunes CA, Strussmann C. 2018. Advertisement calls of topotypes of Elachistocleis matogrosso (Anura: Microhylidae). Salamandra 54: 92 - 96.","Peloso PLV, Sturaro MJ, Forlani MC, Gaucher P, Motta AP, Wheeler WC. 2014. Phylogeny, taxonomic revision, and character evolution of the genera Chiasmocleis and Syncope (Anura, Microhylidae) in Amazonia, with descriptions of three new species. Bulletin of the American Museum of Natural History 386: 1 - 112.","Duellman WE. 1978. The Biology of an Equatorial Herpetofauna in Amazonian Ecuador. Lawrence: University of Kansas.","de Carvalho AL. 1954. A preliminary synopsis of the genera of American microhylid frogs. Occasional Papers of the Museum of Zoology. UniVersity of Michigan 555: 1 - 22.","Cope ED. 1889. Batrachia of North America. Bulletin of the United States National Museum 34: 5 - 525.","Greenbaum E, Smith EN, de Sa RO. 2011. Molecular systematics of the Middle American genus Hypopachus (Anura: Microhylidae). Molecular Phylogenetics and EVolution 61: 265 - 277.","Zweifel RG, Myers CW. 1989. A New Frog of the Genus Ctenophryne (Microhylidae) from the Pacific Lowlands of Northwestern South America. American Museum NoVitates 2947: 1 - 16.","Caramaschi U, Jim J. 1983. A new microhylid frog, genus Elachistocleis (Amphibia, Anura), from northeastern Brasil. Herpetologica 39: 390 - 394.","Nunes-de-Almeida CHL, Toledo LF. 2012. A new species of Elachistocleis Parker (Anura, Microhylidae) from the state of Acre, northern Brazil. Zootaxa 3424: 43 - 50."]}