Wednesday, August 8, 2018

[Herpetology • 2018] Taxonomy of Litoria graminea (Anura: Hylidae), with Descriptions of Two closely related New Species; Litoria nullicedens & L. pallidofemora

Litoria nullicedens Kraus, 2018

I clarify the correct provenance and taxonomic identity of the poorly known canopy-dwelling frog, Litoria graminea, from New Guinea. I base my redescription upon analysis of relevant historical material as well as upon more recently obtained specimens from several localities in Papua New Guinea. Determining the correct identity of L. graminea makes clear that one recently named species (L. dux Richards & Oliver) is a junior synonym of that taxon and that additional close relatives of that species remain undescribed, two of which I describe here. The first is known from a series of localities along the southern versant of the Central Dividing Range and the Owen Stanley Mountains. The second is known from a single site in the foothills of the Owen Stanley Mountains in Central Province, Papua New Guinea. Differences among the species are largely confined to pigmentation features and the shape of the male nuptial pads. Further, I show that several morphometric and color-pattern features earlier thought to distinguish among members of this complex are encompassed by natural variation within true L. graminea, making the characters taxonomically uninformative. The two newly described species share the unusual feature of having green oral mucosa, although their bones were white in life. This coloration is presumably due to sequestration of biliverdin, as seen in a few other tropical treefrogs, but the function of this sequestration remains unknown.

Keywords: Litoria nullicedens sp. nov., Litoria pallidofemora sp. nov., Papua New Guinea, sibling species, species complex, treefrog, Amphibia

Litoria graminea (Boulenger, 1905)
Etymology. The name is a feminine Latin adjective meaning “grassy” and is no doubt in reference to the species’ green coloration.

Litoria pallidofemora, sp. nov.
Etymology. A feminine compound adjective derived from the Latin “pallidus”, meaning “pale”, and “femoris”, meaning “femoral”, in recognition of one of the diagnostic features of this species.

Portraits in life of holotype of Litoria nullicedens sp. nov. (BPBM 18440), Dorobisoro, Central Province.

Litoria nullicedens, sp. nov.
Etymology. The name is an invariant compound adjective derived from combining the Latin first-person present participle “cedo”, meaning “I yield”, and the dative of “nullus”, meaning “none” (hence, “I yield to none”), in recognition of the striking color pattern of the species among Papuan frogs.

Fred Kraus. 2018. Taxonomy of Litoria graminea (Anura: Hylidae), with Descriptions of Two closely related New Species. Zootaxa. 4457(2); 264–284. DOI:  10.11646/zootaxa.4457.2.3