Compiled and Edited by:
Nancy B. Simmons and Andrea L. Cirranello
American Museum of Natural History

Your search for Myotis guarani resulted in 1 species-level match:

Myotis Kaup, 1829. Skizz. Entwickel.-Gesch. Nat. Syst. Europ. Thierwelt 1: 106.

Vespertilio myotis Borkhausen, 1797

Myotis guarani Novaes, Cláudio, Bertocchi, de Oliveira, Semedo, Saldanha, Wilson, & Moratelli, 2025.
J. Mammal. gyaf016: 5.
Guaraní Myotis

Brazil: Mato Grosso; Poconé, Fazenda São João

N Bolivia and W Brazil through Paraguay to N Argentina

CITES - Not Listed IUCN - Not Evaluated (new species).

References:

Novaes, R.L.M., V.C. Cláudio, N.A. Bertocchi, K. de Oliveira, T.B.F. Semedo, J. Saldanha, D.E. Wilson, and R. Moratelli. 2025. Unveiling the shelf life: a new cryptic species of Myotis (Chiroptera, Vespertilionidae) from South America revealed by an integrative taxonomy approach. Journal of Mammalogy gyaf016: 1-20. Read abstract.