A relict tropical forest bat assemblage from the early Miocene of the Ribesalbes-Alcora Basin (Castelló, Spain)

Abstract

We present the bat assemblage from the early Miocene (MN4, 16.9-15.95 MY) basin of Ribesalbes-Alcora, which has yielded the remains of ten chiropteran taxa. Bat assemblages are rarely recovered in the fluvio-lacustrine fossil record. A bat species described in this work, Cuvierimops penalveri sp. nov., is a new form of a typically Oligocene free-Tailed bat. In addition, the other molossids Hydromops helveticus, Rhizomops cf. brasiliensis, Chaerephon sp., Tadarida sp., and the vespertilionids Myotis cf. intermedius and Miostrellus aff. petersbuchensis, as well as undetermined fossils ascribed to the genera Submyotodon, Plecotus, and Rhinolophus are described. This is the first record of the genus Rhizomops in the early Miocene; the genus Cuvierimops is the first recording from the Neogene, while the 'Lazarus taxon' Chaerephon is the first fossil record of this genus, registered previously only in Holocene deposits. This bat assemblage with a high abundance of molossids is typical from the early Oligocene of western Europe, while in the early Miocene from Europe the molossids are scarce. The abundance of these bats is consistent with the presence of a tropical forest surrounding a paleolake. The fossils from the Ribesalbes-Alcora Basin represent the most complete bat assemblage of the Iberian Peninsula during this age, and significantly increase our knowledge about the early Miocene bats of Europe.