POTAMORANA, Brown & Siler & Richards & Diesmos & Cannatella, 2015

Brown, Rafe M., Siler, Cameron D., Richards, Stephen J., Diesmos, Arvin C. & Cannatella, David C., 2015, Multilocus phylogeny and a new classification for Southeast Asian and Melanesian forest frogs (family Ceratobatrachidae), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 174 (1), pp. 130-168 : 149-150

POTAMORANA SUBGEN. NOV.

Type species

Rana bufoniformis Boulenger, 1884 .

Diagnosis

River frog species of the subgenus Potamorana differ from other subgenera of Cornufer , except giant water frogs of the subgenus Discodeles , and Fijian frogs subgenus Cornufer (= Tanuboto) by having (1) a large body size (males 50–75 mm SVL; females 65–140; vs. most species male SVL ∼ 25–40 mm; (2) moderately extensive, but reduced compared with Co. (Discodeles) guppyi , interdigital webbing of feet (vs. highly reduced to vestiges ( Cornufer nexipus ) or absent (all other species); (3) extensive rugosity of dorsal body skin (vs. smooth, weakly rugose, or slightly shagreened body skin); (4) non-expanded terminal discs of fingers and toes (vs. widely expanded in some arboreal riddle frogs of subgenus Aenigmanura , palm frogs of subgenus Palmatorappia , giant water frogs of subgenus Discodeles , and a few sticky-toed frogs of subgenus Batrachylodes ); and (5) semiaquatic microhabitat preferences (vs. terrestrial). Based on the phylogeny, we consider their large body size, interdigital webbing of the feet, and semiaquatic microhabitat preferences to be shared, derived characters that unambiguously distinguish the species of Potamorana from all other species of Cornufer except Discodeles guppyi , in which these characters most likely have independently evolved ( Fig. 2).

Phylogenetic definition

Potamorana (NCN) is an apomorphy-based name for the clade ( Fig. 2, Clade F) originating in the ancestor of Cornufer bufoniformis and Cornufer malukuna in which the following apomorphy, synapomorphic with that in the various populations of Co. bufoniformis , originated: moderately extensive webbing between the digits of the feet.

Content

Cornufer malukuna and Co. bufoniformis ( Table 3). We did not sample Cornufer (Discodeles) opisthodon or Cornufer (Discodeles) vogti but we tentatively place them in Potamorana because these species share the synapomorphy (moderately extensive webbing between the digits of the feet) of the clade Potamorana .

Comment

The newly discovered relationships of the former ‘ Discodeles ’ malukuna and ‘ Discodeles ’ bufoniformis reveal that Discodeles was polyphyletic in its former sense. These species are unrelated to the clade ( Fig. 2, Clade H) containing the type species D. guppyi . In retrospect, it is not surprising that these four morphologically similar (moderate body size, moderate interdigital webbing, terminal digital discs non-expanded) species are now recognized as distinct from Co. (Discodeles) guppyi , a much larger species with full interdigital webbing between the toes and moderately expanded terminal digital discs.

Etymology

Derived from the Greek term potamo, meaning ‘river or stream’, and the Latin rana, meaning ‘frog’, in reference to the semiaquatic habitat preferences of the new clade. The name is feminine in gender. Suggest- ed common name: Solomon−Bismarck river frogs.