Occidozyga Kuhl and Van Hasselt, 1822

Class: Amphibia > Order: Anura > Family: Dicroglossidae > Subfamily: Occidozyginae > Genus: Occidozyga
16 species

Occidozyga Kuhl and Van Hasselt, 1822, Algemeene Konst-en Letter-Bode, 7: 103. Type species: Rana lima Gravenhorst, 1829, by subsequent designation of Stejneger, 1925, Proc. U.S. Natl. Mus., 66: 33.

OoeidozygaKuhl and Van Hasselt, 1822, Isis von Oken, 10: 475. Incorrect subsequent spelling according to Dubois, 1981, Monit. Zool. Ital., N.S., Suppl., 15: 245, and Dubois, 1982, Bull. Mus. Natl. Hist. Nat. Paris, Sect. A, Zool., 4: 269-272.

OccidogynaGray, 1825, Ann. Philos., London, Ser. 2, 10: 215. Incorrect subsequent spelling of Occidozyga Kuhl and Hasselt, 1822.

Houlema Gray, 1831, Zool. Misc., Part 1: 38. Type species: Houlema obscura Gray, 1831, by monotypy. Synonymy by Dubois, 1981, Monit. Zool. Ital., N.S., Suppl., 15: 245.

Oxyglossus Tschudi, 1838, Classif. Batr.: 48. Type species: Rana lima Gravenhorst, 1829, by monotypy. Synonymy by Stejneger, 1925, Proc. U.S. Natl. Mus., 66: 33.

OxydozygaTschudi, 1838, Classif. Batr.: 85. Incorrect subsequent spelling of Occidozyga Kuhl and Van Hasselt, 1822.

Rhomboglossus Duméril and Bibron, 1841, Erp. Gen., 8: 332. Substitute name for Oxyglossus Tschudi, 1838.

Phrynoglossus Peters, 1867, Monatsber. Preuss. Akad. Wiss. Berlin, 1867: 29. Type species: Phrynoglossus martensii Peters, 1867, by monotypy. 

Microdiscopus Peters, 1877, Monatsber. Preuss. Akad. Wiss. Berlin, 1877: 421. Type species: Microdiscopus sumatranus Peters, 1877, by monotypy. Synonymy with Occidozyga by Boulenger, 1882, Cat. Batr. Sal. Coll. Brit. Mus., Ed. 2: 5 (although O'Shaughnessy, 1879, Zool. Rec., 14: 12, suggested that Microdiscopus and Oxyglossus "correspond closely"). Transfer of synonym to Phrynoglossus by Fei, Ye, and Jiang, 2010, Herpetol. Sinica, 12: 30. 

Oreobatrachus Boulenger, 1896, Ann. Mag. Nat. Hist., Ser. 6, 17: 401. Type species: Oreobatrachus baluensis Boulenger, 1896. Synonymy with Phrynoglossus by Smith, 1931, Bull. Raffles Mus., 5: 16. See comment. 

OxyglossisSmith, 1916, J. Nat. Hist. Soc. Siam, 2: 164. Incorrect subsequent spelling.

Osteosternum Wu, 1929, Contrib. Biol. Lab. Sci. Soc., China, Zool. Ser., 5: 3. Type species: Osteosternum amoyense Wu, 1929, by original designation. Synonymy by Smith, 1931, Bull. Raffles Mus., 5: 16.

Frethia Dubois, Ohler, and Pyron, 2021, Megataxa, 5: 243. Type species: Oxyglossus laevis Günther, 1859. See comment. 

English Names

Java Frogs (Frank and Ramus, 1995, Compl. Guide Scient. Common Names Amph. Rept. World: 102).

Oriental Frogs (Phrynoglossus [no longer recognized]: Frank and Ramus, 1995, Compl. Guide Scient. Common Names Amph. Rept. World: 104).


West Bengal (India) through Bangladesh, Myanmar, Thailand, and Laos, to southern China (southern Yunnan, southern Guangxi, Guangdong, Hainan, to southern Jiangxi, and eastern Fujian), Vietnam, to Malaya (Malaysia) and into the Greater Sundas, Bali, and Philippines. 


In the subfamily Occidozyginae Fei, Ye, and Huang, 1990, according to Dubois, Ohler, and Biju, 2001, Alytes, 19: 55. Dubois, 1987 "1986", Alytes, 5: 59, resurrected Phrynoglossus from synonymy and recognized two species groups noted in the accounts: the Phrynoglossus laevis group (including Phrynoglossus baluensis, Phrynoglossus celebensis, Phrynoglossus floresianus, Phrynoglossus laevis, Phrynoglossus magnapustulosus, Phrynoglossus martensii, Phrynoglossus semipalmatus, and possibly Phrynoglossus vittatus) and the Phrynoglossus borealis group (including Phrynoglossus borealis and Occidozyga diminutivus). Inger, 1996, Herpetologica, 52: 241-246, discussed inconsistencies in the diagnosis of Phrynoglossus, replaced it in the synonymy of Occidozyga, and noted that the species Occidozyga lima (in Occidozyga of Dubois) and Occidozyga baluensis, Occidozyga celebensis, Occidozyga laevis, and Occidozyga semipalmatus (all in Phrynoglossus sensu Dubois) likely formed a monophyletic group. Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006, Bull. Am. Mus. Nat. Hist., 297: 243, confirmed the synonymy of Phrynoglossus and Occidozyga, as did Pyron and Wiens, 2011, Mol. Phylogenet. Evol., 61: 558. Köhler, Vargas, Than, Schell, Janke, Pauls, and Thammachoti, 2021, Vert. Zool., Senckenberg, 71: 1–26, discussed and redelimited the generic boundaries of Phrynoglossus and Occidozyga on the basis of morphology and a 16s mtDNA tree of 4 of 12 species restricted to one segment of the overall range, Indochina, which differs significantly from the presumably more data-heavy (not checked by DRF), and somewhat more terminal-heave terminal-light (5 of 12 species) tree of Pyron and Wiens, 2011, Mol. Phylogenet. Evol., 61: 558. TPreviously, Phrynoglossus was considered a junior synonym of Occidozyga by Stoliczka, 1872, Proc. Asiat. Soc. Bengal, 1872: 101; Inger, 1996, Herpetologica, 52: 243; and Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006, Bull. Am. Mus. Nat. Hist., 297: 243. Zug, Mulcahy, Vindum, and Wilkinson, 2018, Alytes, 36: 272, briefly discussed five cryptic lineages of nominal Phrynoglossus found in Tanintharyi Province, peninsular Myanmar, although this was not cited by Köhler et al., 2021, nor were the lineages detected in their rather slim dataset. Dubois, Ohler, and Pyron, 2021, Megataxa, 5: 1–738, based on what is probably nearly the same dataset as studied by Jetz and Pyron, 2018, Nature Ecol. & Evol., 2: 850–858), a substantially larger amount of sequence but less dense taxon sampling than employed by Köhler et al. (2021), came to very different phylogenetic conclusions and recognized two other genera, even though only 5 of 12 species were included in their study. These new genera are Frethia and Oreobatrachus, besides Phrynoglossus and Occidozyga, rendering by their lights a monophyletic classification. However, inasmuch as retaining everything in Occidozyga also provides a monophyletic classification, DRF retains the older generic classification in order to let the water settle a bit and see how the community responds to the three alternative classifications and to see what develops once the species are geographically and taxonomically densely sampled genetically. Flury, Haas, Brown, Das, Min, Kueh, Scheidt, Iskandar, Jankowski, and Hertwig, 2021, Mol. Phylogenet. Evol., 163 (107210): 1–17, provided an mt + nuDNA study of Occidozyga populations from the Philippines, Borneo, Sumatra, Thailand, Laos, and Cambodia, with the focus primarily on Sundaland and the Philippines, suggesting that most or all of the nominal species are complexes (which they delimited as groups, e.g., the rhacoda group) and that many species need to be named before we have a good understanding of the phylogenetic and biogeographic history of the lineages within Occidozyga. Within their Occidozyga they recognized 29 divergent lineages (>5% sequence divergence) which fall into five well-supported clades of cryptic species with resolution within the groups only weakly supported: (1) baluensis group; (2) laevis group; (3) sumatrana group; (4) rhacoda group; and (5) lima group. In addition, the latest revision to appear, that of Trageser, Al-Razi, Maria, Nobel, Asaduzzaman, and Rahman, 2021, PeerJ, 9 (e11998): 1–32, based solely on 16s mtDNA (what seems to be the standard in India and Bangladesh regardless of the obvious problems with a dataset of solely maternally-inherited genetic material), adopted the taxonomy of Köhler et al. Interestingly enough, when the four trees (Dubois et al., 2021; Köhler et al., 2021; Jetz and Pyron, 2018; and Trageser et al., 2021) are superimposed the need for increased taxon and locus-sampling is made obvious. One interesting item is that Occidozyga baluensis of Frost (2006), employed by Jetz & Pyron (2018) and Dubois et al. (2021) appears far removed from the Occidozyga baluensis of Trageser et al., 2021. This may be due to misidentification or to analytic differences. Rather than competing generic arrangements, what we need is a dense study of well-identified and vouchered terminals (DRF). Chan, Hutter, Wood, Su, and Brown, 2021, Syst. Biol.: 40–57, suggested that gene flow increases cryptic species estimates employing Occidozyga laevis populations in the Philippines. Chan, Hertwig, Neokleous, Flury, and Brown, 2022, BMC Ecol. Evol., 22 (37): 1–9, reported on the instability of results based solely on 16S rDNA, employing Occidozyga (sensu lato) as an example. 

Contained taxa (16 sp.):

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