Description
Xenorhina lacrimosa is a medium-sized microhylid frog described from five males, two females, and one juvenile. The snout-urostyle length in males ranged from 34.5 - 41.0 mm and the females were 34.3 mm and 35.1 mm in snout-urostyle length. The head is broader than it is long, with a pointed snout that protrudes in the profile view. There are “tiny elevations” on the tip of the snout, especially on the underside. There are two long, acuminated spikes, one on each vomeropalatine bone. The laterally directed nostrils are positioned closer to the tip of the snout than the eye and not visible from the ventral view. The internarial distance is smaller than the distance between the nostrils and the eyes. The loreal region has an oblique shape and there is no canthus rostralis. The eye diameter is equal to or greater than the tympanum diameter. A weak supratympanic fold is present, extending from behind the eye to the insertion of the forelimb. There are scattered tubercles in the middle of the dorsum and on the dorsal surfaces of the limbs. The lateral surfaces of the body have many distinct tubercles, which are less prominent in preservative. All ventral surfaces of the body and limbs are smooth. The hands do not have metacarpal tubercles. The unwebbed fingers are moderately short, with relative finger lengths 3 > 4 = 1 = 2. All finger tips possess circummarginal grooves, but the tips are not wider than the fingers. The subarticular tubercles of the fingers are barely visible. The tibia is 42 - 46% of the snout-urostyle length. There is a prominent, oval inner metatarsal tubercle, but no outer. The unwebbed toes have relative lengths of 4 > 3 > 5 > 2 > 1. All toe tips are wider than the penultimate phalanges and possess circummarginal grooves. Barely visible subarticular tubercles are also present on the toes (Günther and Richards 2021).

DIAGNOSIS: Written entirely by Ann

Xenorhina lacrimosa is similar in size to X. fuscigula, X. huon, X. subcrocea and X. zweifeli and they all have a single spike on each of their vomeropalatine bones. However, the species can be differentiated by morphology, coloration, and advertisement call. More specifically, X. lacrimosa is larger than both X. huon and X. subcrocea. Xenorhina lacrimosa has relatively longer hind limbs than X. fuscigula and X. huon, but shorter than X. subcrocea. The internarial distance and relative eye diameter in X. lacrimosa is smaller than in X. huon, and the eye to-naris distance is longer than X. fusigula. The presence of an inner metatarsal tubercle in X. lacrimosa differentiates it from X. fuscigula, which has no planter or palmar tubercules. The orange-red or grey-brown ventrum with little to no brown reticulations in X. lacrimosa differentiate it from the black ventrum of X. fuscigula, dark flecking in X. huon, and the dark reticulations in X. sucrocea. Xenorhina lacrimosa is the most similar to X. zweifei in both size and body proportions, but they differ in that X. zweifeli has a dark brown supra tympanic stripe, which X. lacrimosa lacks. With regards to advertisement call, the 7 - 12 call series of X. lacrimosia differentiates it from the single note call of X. fuscigula and X. zweifei. The length of the call is longer in X. lacrimosia than in X. subcrocea, but shorter than X. zweifeli. The intercall interval is also longer in X. lacrimosia than in X. subcrocea and more regular than X. zweifeli. The fundamental and dominant frequency in X. lacrimosa are both shorter than in X. zweifeli, the amplitude rise time in X. zweifeli is slower, and the timing of the frequency modulation in the harmonics differ. Lastly, the geographic ranges of X. lacrimosia and X. zweifei are separated by New Guinea’s central cordillera (Günther and Richards 2021). Xenorhina lacrimosa has also been compared to X. ventrimaculata with the focal species being larger, having a larger ratio for their eye to nares to internarial distance, having larger first and fourth toe discs relative to their body length, and shorter call repetition rate (Günther et al. 2021).

COLORATION:

In life, color among specimens varies significantly. Generally, the dorsal surface of the head, the anterior portion of the body, and all forelimbs can be a blueish-brown, a uniform red-orange, or mix of colors. The body has a light yellow mid-dorsal line and another light yellow line that travels down along the hind legs. The other dorsal surfaces and the flanks are a mix of a dark, saffron-yellow and blue-gray pattern. The tubercles have a brown base and a white tip. In the holotype, lumbar region possesses a light yellow semi-circular patch and the vent region has a dark triangular-shaped patch. On the toes, the plantar and ventral surfaces are brown. On the hands, the palms and ventral side of the fingers are gray and cream. Ventral surfaces on the throat, chest, and abdomen are also highly variable with either a red-orange or greyish-brown background color with white, orange, or brown spots. The irises are a deep black with slight golden reticulation (Günther and Richards 2021).

In preservatives, the dorsal surfaces of the head, forelimbs, and anterior back can vary between violet, copper brown, beige, or beige-brown. Most individuals have a light ivory mid-dorsal line. The snout tip becomes greyish. The tubercles remain brown with white apices. Ventral surfaces are all light ivory (Günther and Richards 2021).

VARIATION:

There is limited morphological variation among X. lacrimosa specimens, and there does not appear to be any sexual dimorphism as males and females are the same size, with insignificant differences in measurements. However, color among specimens varies significantly. In life, the dorsal surfaces can be a uniform blue-brown, a uniform red-orange, or mix of colors. Mixes can include blue on the head and flanks but reddish-brown on the back and extremities or dark brown with blue on the head, body and thighs, but beige on forelimbs and shanks. The ventral surfaces range between three variations: A deep or bright orange with irregular white spots, a mix of white, orange, and brown spots with the throat and thighs being uniform bright orange, or a grayish-brown ground color with irregular white spots. In preservative, color variations include violet, copper brown, beige, or beige-brown dorsal surfaces. Ventral surfaces are either light ivory or ivory with a brown-beige pattern (Günther and Richards 2021).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Papua New Guinea

View distribution map in BerkeleyMapper.

All specimens were found in the south-central Papua New Guinea at elevations ranging from sea level to 950 m a.s.l., but the elevational range may be as high as 1,400 m a.s.l. Their habitat consists of lowland and foothill forests (Günther and Richards 2021).

Life History, Abundance, Activity, and Special Behaviors
Specimens were found under leaf litter on the forest floor and in the humus layer further beneath the litter (Günther and Richards 2021).

Males produce advertisement calls at night, typically after rainfall, from leaf litter or from the humus layer, several centimeters below the litter. At air temperatures between 21.2 and 25.5 °C, the calls are singular, unpulsed notes that are always produced in a series. The volume and pitch increase throughout the series gradually. The calls begin at a high amplitude and continue to rise quickly to a maximum before decreasing gradually. The call series lasts 26.4 - 60.4 s with 7 - 12 calls per series. Each call lasts 141 - 231 ms and has an intercall interval of 2.8 - 8.0 s, with the first and last calls being shorter. The calls have 5 - 7 harmonics with the dominant frequency of 1.2 kHz being carried by the first or second harmonic (Günther and Richards 2021).

Comments
This species was described based on morphology and advertisement call (Günther and Richards 2021).

OTHER INTERESTING INFORMATION:

The elevational range of X. lacrimosa may change pending genetic confirmation of an additional morphologically similar specimen found at 1400 m. The higher altitude specimen is also considerably larger than the type specimens and thus its relationship needs confirmation by genetic testing (Günther and Richards 2021).

References
Günther, R., and Richards, S. (2021). Description of six new species of Xenorhina Peters, 1863 from southern Papua New Guinea (Amphibia, Anura, Microhylidae). Zoosystematics and Evolution, 97(2), 355–382. [link]

Günther, R., Dahl, C., and Richards, S. J. (2021). Description of a new Xenorhina species (Anura, Microhylidae) from northwestern Papua New Guinea. Vertebrate Zoology, 71, 621-630. [link]

Species Account Citation: AmphibiaWeb 2025 Xenorhina lacrimosa <https://amphibiaweb.org/species/9410> University of California, Berkeley, CA, USA. Accessed Jun 14, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 14 Jun 2025.

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