GUWAHATI
Scientists from the Zoological Survey of India (ZSI) have resolved longstanding taxonomic ambiguities surrounding South Asian treeshrews – small, insectivorous mammals usually misidentified as a consequence of their superficial resemblance to squirrels. Drawing upon century-old specimens housed in nationwide collections, the examine gives contemporary perception into the morphological range of these elusive creatures.
Their examine was printed in Ecology and Evolution, a world journal, on Friday (April 25, 2025). The authors of the examine are Manokaran Kamalakannan, Mukesh Thakur, Nithyanandam Marimuthu, Subhojit Pramanik, and Dhriti Banerjee.
Treeshrews are neither true shrews nor squirrels, however belong to a definite order known as Scandentia. While they share the same measurement and arboreal life-style with squirrels, treeshrews could be simply distinguished by their elongated snouts, lowered whiskers, moist nasal pads, and insectivorous or frugivorous food plan.
Historically misclassified as primates, the treeshrews – some arboreal, some semi-arboreal, and others terrestrial – are actually recognised as an historical lineage of mammals endemic to South and Southeast Asia.
Dr. Kamalakannan, the lead writer and scientist on the ZSI’s Mammal and Osteology Section, conceptualised and led the examine from knowledge assortment to the ultimate morphological evaluation. “By examining decades-old museum specimens, we have shed light on how these fascinating mammals differ from one another,” he stated.
“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 stated.
Co-author Dr. Marimuthu, who led the advanced multivariate analyses, stated: “The morphometric patterns we uncovered offer strong statistical support for separating these species, which were once thought to overlap significantly in size and shape.”
Most strikingly, the examine overturns long-standing assumptions in regards to the Nicobar treeshrew. Once believed to be the smallest amongst South Asian treeshrews, the evaluation reveals it’s the largest in South Asia and the third-largest of all 23 recognized treeshrew species globally.
More analysis suggested
“There is a need for genetic studies to support a comprehensive phylogenetic analysis of South Asian treeshrews. This should be a priority for future research,” Dr. Thakur, one other co-author, stated.
Dr. Banerjee, additionally the Director of ZSI, underlined the implications of the findings. “This study is a major step forward in mammalian conservation in South Asia. Accurate taxonomy is fundamental to protecting species, particularly insular endemics like the Nicobar treeshrew, which faces growing ecological pressures,” she stated.
The analysis utilised a large dataset from South Asian treeshrew specimens preserved for over a century on the ZSI’s National Zoological Collections, a repository of India’s faunal range, in Kolkata.
The scientists investigated the morphological variation amongst three species – Madras treeshrew (Anathana ellioti), northern treeshrew (Tupaia belangeri), and Nicobar treeshrew (Tupaia nicobarica) – utilizing museum specimens collected over a large spatial and temporal vary of India and Myanmar and mixed with current printed datasets.
These three species occupy distinct and non-overlapping geographical areas in India and Southeast Asia.
The scientists analysed 22 cranial measurements and 4 exterior traits to judge inter- and intraspecific morphological differentiation, using distance-based morphometric approaches validated by multivariate analyses. Their findings revealed appreciable heterogeneity in cranial morphology, with three species exhibiting clear differentiation, regardless of slight overlaps in morphospace.
Published – April 25, 2025 04:21 pm IST
