'' from the early
Paleocene (61
Mya).
O.C. Marsh originally described
Nyctitherium, from the Eocene of
Wyoming, as an early bat based on similarities of its teeth. Since 1872 more than two dozen other genera of nyctitheriids have been named, and several of these have also initially been considered bats.
G.G. Simpson recognized that
Nyctitherium did not represent a bat, and in 1928 named the family Nyctitheriidae for
Nyctitherium and several other small insectivores. Many additional species of Nyctitheriidae from Asia, Europe, and North America have been recognized in the subsequent decades. Most species are known only from isolated teeth and jaw fragments, however species of
Cryptotopos,
Euronyctia,
Plagioctenodon, and
Scraeva are known from some
postcranial bones. == Evolutionary relationships ==