Unveiling the shelf life: a new cryptic species of <i>Myotis</i> (Chiroptera, Vespertilionidae) from South America revealed by an integrative taxonomy approach

Abstract Myotis is a diverse genus of vesper bats with a global distribution. Currently, over 35 Neotropical species are recognized, but molecular studies suggest the existence of a large number of distinct evolutionary lineages, revealing cryptic diversity. Thus, this genus poses a challenge for systematists since its high species diversity is not reflected in phenotypic differences. Using an integrative approach, we identified and described here a new species of Myotis. Ecological niche modeling indicates a strong association with the South American Chaco, Pantanal, and Cerrado ecoregions—spanning Argentina, Bolivia, Paraguay, and Brazil. Phylogenetic inference, genetic divergence, and morphological analyses support the recognition of the new species. Additionally, we present a set of external and skull diagnostic characters by comparing them with other Neotropical Myotis species. Specimens of this new species have been deposited in biological collections for more than 120 years. This discovery underscores the importance of systematic studies based on multiple lines of evidence and highlights the crucial role of natural history museums as biological repositories.