Undescribed Population of Calumma cf. radamanus from Northwestern Madagascar

There appears to be a population of Calumma cf. radamanus in northwestern Madagascar, clearly distinct from the syntopic Calumma boettgeri. The first documentation was made in 2019, when a female specimen was photographed in situ. Because the record was of a female, the morphology of the male remains unknown, leaving a critical gap in the characterization of this taxon.

Since that initial observation, local guides have repeatedly reported the occurrence of a small chameleon that they identify as Calumma cf. nasutum. Their descriptions emphasize diminutive size, absence of occipital lobes, and a laterally flattened rostral appendage. However, these accounts remain anecdotal, as no photographic or voucher evidence has yet been secured to substantiate the reports.

Prötzel et al. (2020) provided a detailed account of the morphological variation of C. radamanus, documenting its distribution in northeastern Madagascar from Tampolo to Ambatondradama at elevations between 7 and 500 m. In the absence of alternative described taxa, current consensus among herpetologists is that all northern Madagascar records of small Calumma species with a soft rostral appendage and lacking occipital flaps should be provisionally referred to C. radamanus. The northwestern population, however, may represent a distinct, undescribed lineage, underscoring the need for targeted surveys, male specimens, and integrative taxonomic analysis to clarify its status.