Molossid Bats from the Late Tertiary of Florida with a Review of the Tertiary Molossidae of North America

Abstract

The fossil history of molossids in the North American Tertiary is among the poorest for any family of bats. The oldest definite record is of Wallia scalopidens of middle Eocene (Uintan) age from Saskatchewan, Canada. One of the youngest records is of Eumops cf. E. perotis from the late Pliocene (late early Blancan) of Arizona, USA. New occurrences detailed herein from the middle and late Tertiary of Florida, USA, begin to fill in the 40-million-year gap between the previous records. They are: (1) an abraded upper molar of an indeterminate genus from the Brooksville 2 locality, Hernando County, of late Oligocene (Arikareean) age; (2) a large and a small upper molar pertaining to two congeneric species similar to Tadarida and Mormopterus, from the Thomas Farm local fauna, Gilchrist County, of early Miocene (early Hemingfordian) age; and (3) a distal humerus from a Tadarida of an unknown species that is larger than extant Tadarida brasiliensis and similarly sized but differently proportioned than in the extinct Pleistocene species Tadarida constantinei. The last specimen is from the Macasphalt Shell Pit, Sarasota County, and is of late Pliocene (late Blancan) age.