Craniometric variation and taxonomic boundaries in the Madras Treeshrew (Scandentia, Tupaiidae: Anathana ellioti [Waterhouse, 1850]) from India

The Madras Treeshrew, Anathana ellioti (Waterhouse, 1850), is a small, poorly studied mammal from South Asia. It is the only treeshrew found across the southern half of the Indian subcontinent and is the westernmost member of its order (Scandentia). The phylogenetic relationship between Anathana and its putative sister genus, Tupaia, remains unresolved, and the morphological differences between these two genera have yet to be analyzed with craniometric data. Here we describe some features that distinguish Anathana from other treeshrews. However, our comparative morphometric analyses reveal that Anathana overlaps with Tupaia in morphospace; it is smaller than most species (including the only other species found on the Indian mainland, T. belangeri) but larger than T. minor, Dendrogale melanura, and Ptilocercus lowii. At the infraspecific level, there is some separation between eastern and western populations, but this requires further investigation with larger sample sizes. Unfortunately, Anathana is disproportionately scarce in museum collections relative to other scandentians, and additional biological surveys across South India will be critical for future research on the taxonomy, distribution, and conservation of this elusive taxon.