On one of the smallest Amazonian scorpions: a new species of Microtityus Kjellesvig-Waering, 1966 (Scorpiones, Buthidae) from Brazil, with amended diagnosis and potential distribution analysis for the genus

A new scorpion species, Microtityus adriki n. sp., is described based on adult specimens collected in Canta, state of Roraima (RR), northern Brazil. Microtityus adriki n. sp. is the second species of Microtityus Kjellesvig-Waering, 1966 known from Brazil and is one of the smallest scorpion species (12.39-19.47 mm) in the Amazonian region. In this study, we propose an amended generic diagnosis and a specific diagnosis, describe the male hemispermatophore of Microtityus, give the sequence of COI barcode, and present a potential distribution analysis for the genus. The morphology of the male hemispermatophore of Microtityus differs from that of other Neotropical buthid genera, except for the number of lobes (three lobes), which is a character state shared with several genera. The potential distribution model generated by MaxEnt suggests high environmental suitability for the genus in the Antilles and northern South America, with scattered high suitability in several regions of Central America. However, the model did not indicate high suitability in areas where Brazilian species occur (i.e., Microtityus adriki n. sp. and Microtityus vanzolinii Lourenco & Eickstedt, 1983), and this could be explained by a sampling bias. Therefore, future studies, including extensive sampling, are required to better understand the biogeographic processes behind the distribution of this genus.