Centuries-old museum specimens unlock mysteries of South Asian treeshrews

ZSI scientists resolve taxonomic ambiguities surrounding South Asian treeshrews, highlighting morphological diversity and distinctiveness in new study.

GUWAHATI

Scientists from the Zoological Survey of India (ZSI) have resolved longstanding taxonomic ambiguities surrounding South Asian treeshrews - small, insectivorous mammals often misidentified due to their superficial resemblance to squirrels. Drawing upon century-old specimens housed in national collections, the study offers fresh insight into the morphological diversity of these elusive creatures.

Their study was published in Ecology and Evolution, an international journal, on Friday (April 25, 2025). The authors of the study are Manokaran Kamalakannan, Mukesh Thakur, Nithyanandam Marimuthu, Subhojit Pramanik, and Dhriti Banerjee.

Treeshrews are neither true shrews nor squirrels, but belong to a distinct order called Scandentia. While they share a similar size and arboreal lifestyle with squirrels, treeshrews can be easily distinguished by their elongated snouts, reduced whiskers, moist nasal pads, and insectivorous or frugivorous diet.

Historically misclassified as primates, the treeshrews – some arboreal, some semi-arboreal, and others terrestrial – are now recognised as an ancient lineage of mammals endemic to South and Southeast Asia.

Dr. Kamalakannan, the lead author and scientist at the ZSI’s Mammal and Osteology Section, conceptualised and led the study from data collection to the final morphological analysis. “By examining decades-old museum specimens, we have shed light on how these fascinating mammals differ from one another,” he said.

“This clarity is essential for accurate species identification and for shaping effective conservation policies. When analysed with modern techniques, museum specimens reveal patterns of variation that were previously hidden, helping us address long-standing taxonomic ambiguities,” he said.