An integrative taxonomic revision of lesser gymnures (Eulipotyphla: Hylomys) reveals five new species and emerging patterns of local endemism in Tropical East Asia

D surface scans of type specimen craniums and mandibles are available at MorphoSource: https://doi.org/10.17602/M2/M560011https://doi.org/10.17602/M2/M560006, https://doi.org/10.17602/M2/M560031, https://doi.org/10.17602/M2/M560027, https://doi.org/10.17602/M2/M560022, https://doi.org/10.17602/M2/M560018

We here present a comprehensive integrative taxonomic review of the genus Hylomys, using molecular (mitochondrial genomes and up to five nuclear loci) and morphological data from museum specimens across its distribution, resulting in the description of two new species and the elevation of three subspecies to specific status. This revision significantly increases the known diversity of Hylomys from two to seven extant species, challenging the traditional view of species-level diversity within gymnures. We discuss the implications of the taxonomic findings for conservation, particularly in relation to the restricted distribution ranges of several species that may be threatened by habitat loss and/or climate change. Our research emphasizes the importance of scientific collections and underscores the potential of museum genomics and additional field sampling to identify new species and improve our understanding of species diversity in poorly studied regions. Speciation events within Hylomys occurred during the Late Miocene and Early Pliocene, possibly driven by shifting climate conditions such as the strengthening of the Indian monsoon and the expansion of seasonally dry conditions. This study supports northern Sumatra and the southern Annamites as centres of localized endemicity and suggests the need for additional small mammal surveys across Sumatra's Barisan Range.

The Spanish Ministry of Science and Innovation grants CGL2014-58793- P and CGL2017- 86068- P and PID2020- 120115GB- 100 to J.A.L., and Smithsonian Institution’s discretionary startup funds to M.H. supported this study. A.H. was supported by a Ministerio de Economía y Competitividad contract CGL2014-58793- P and a ‘Margarita Salas’ postdoctoral grant funded by the Ministerio de Universidades de España and the European Union ‘NextGenerationEU’. A.H. was also supported by an Ernst Mayr Travel grant.

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