Micronycteris sp.

Soeiro, Andreza & Bezerra, Alexandra M. R., 2024, Bats (Mammalia: Chiroptera) from two priority areas for biodiversity conservation in the Brazilian Amazon and range extension for Carollia benkeithi (Phyllostomidae), Mammalia (Warsaw, Poland) 88 (5), pp. 436-444 : 438-441

3.2 Morphological diagnosis of the specimen Micronycteris sp.

At first, we thought that specimen MPEG 37789 was of the rare species N. pusilla , last recorded over 70 years ago. However, upon closer examining and, comparing with the holotype of N. pusilla (AMNH 78830), we realized that it belongs to the genus Micronycteris , but it does not match morphological characters of the currently recognized species. Our specimen, a female (MPEG 37789) ( Figures 4 and 5 ), seems to belong to the informal group of dark-bellied Micronycteris ( Simmons 1996) . Its morphological characteristics include: self-colored orange-reddish fur color on both ventral and dorsal sides ( Figure 4A ), forearm length of 34.72 mm, ears rounded and separated by small flaps ( Figure 4B ), ear length of 18.70 mm, short hairs on the inner edge of ears (3 mm), finely rounded nose leaf shape, 3rd metacarpal shorter than the 4th metacarpal, longest skull length of 18.37 mm, developed mandibular 3rd premolar, absent mandibular 4th premolar, and a tooth formula I 2/2, C 2/2, P 2/3, M 3/3.

Craniodental characters, such as the upper external incisors visible to the naked eye and the developed upper premolars, can be observed in Figure 5 . Unfortunately, this specimen was not well-preserved, and its very fragile skull was broken and fragmented.

Figures

Figure 4: Female specimen of Micronycteris sp. (MPEG 37789) registered in the Mamirauá SDR. (A) Dorsal (left) and ventral (right) fur views; (B) two upper dorsal views of the head showing the separation of the ear band (arrows). Scale bars: 10 mm.

Figure 5: Skull of Micronycteris sp. (MPEG 37789, female). (A) Lateral view of the skull shows the developed maxillary premolars; (B) dorsal skull view; (C) maxillary external incisors visible to the naked eye (arrow); and (D) lateral views of mandible. Scale bar:5 mm.