Alvarez's mastiff bat

Alvarez's mastiff bat, Molossus alvarezi, is a bat of the family Molossidae that is native to the Yucatán Peninsula. It was described as a new species in 2011, when researchers comparing specimens of the Sinaloan mastiff bat found that animals from the Yucatán Peninsula were morphologically distinct from those of other regions. The species name honors the Mexican mammalogist José Ticul Álvarez Solórzano, and a 2019 genetic study of several Molossus species found it to be the sister taxon of Molossus fentoni. It resembles Molossus sinaloae but is smaller in most dimensions, medium-sized for its genus, with a forearm 42.7 to 47.4 millimeters long, dark brown fur on the back and paler grayish brown fur beneath. It is recorded from the Mexican states of Quintana Roo and Yucatán, with a range that also includes Honduras and French Guiana, in perennial forests, low forests and a band of xeric vegetation.