It was described in 2013. Its closest relative is the dark-brown serotine, Neoromicia brunnea. Rosevear's serotine and the dark-brown serotine are separated by a genetic distance of 6.9-7.2%. The new species was assigned to the genus Neoromicia based on its single upper premolar: a trait shared amongst all species in the genus. The authors who described the species chose the specific epithet "roseveari" to honor Donovan Reginald Rosevear, "who made a significant contribution to West African bat research in the 20th century, culminating in his book The Bats of West Africa".
Description
It is a small bat, with a total body length of. Its tail is ; its forearm is long; its hindfoot is long; its ear length is. It has a body mass of. Its maximum skull length is. Despite this small size, it is the largest "pipistrelloid" in West Africa. In some aspects, Eisentraut's pipistrelle overlaps with Rosevear's serotine in size, though they can be differentiated by their morphology. Its fur is dark chocolate brown in color. The fur on its ventral surface is bicolored, with the bases of individual hairs darker than their tips. The fur on its dorsal surface is a constant color throughout, in contrast to the bicolored ventral fur. Its ear is relatively short, and rounded at the tip. The outer edge of the tragus is curved; the base of the tragus has a "distinct lobe." Relative to other species in its genus, it has a robust skull and a broad snout. Its dental formula, typical for Neoromicia species, is, for a total of 32 teeth.
Biology
As only six individuals have ever been encountered, very little is known about the biology of this species. A female captured in Guinea in early March 2008 was pregnant, however, with a fetus from crown to rump.
Only six specimens have ever been documented. Four specimens were recorded on the Liberian border of Mount Nimba and the other two specimens were in the Simandou Range of Guinea. All captured individuals were netted over small streams in primary rainforest. Two of the Mount Nimba individuals were encountered at above sea level.
Conservation
It is currently evaluated as endangered by the IUCN. It meets the criteria for this designation because its extent of occurrence is estimated at less than and its area of occupancy is estimated at less than. Major threats to this species include deforestation via slash-and-burn agriculture, logging, and mining.
