Molossops temminckii (Burmeister, 1854)

Summary of captures.

One female (CMARF 2144) and one male (CMARF 2145).

External measurements and weights.

Female: TLB: 85.00, TL: 33.00, LHL: 5.00, EL: 12.00, W: 6.00. Male: TLB: 80.00, TL: 28.00, LHL: 5.00, EL: 13.00, W: 6.00.

Morphological description.

Dorsal pelage is chestnut-brown at the tips and yellow at the bases, while ventrally, the coloration is slightly paler (Fig. 8). Ears triangular, with a small and triangular tragus. Antitragus broad and slightly inclined posteriorly. Snout elongated, flat, wide, and blunt, featuring a slightly prominent tip and an obtuse projection between the nasal orifices. Lips smooth and bordered by a fine fringe of hook-shaped hairs, accompanied by a tuft of bristles below the nostrils. Small warts or papillae are notably present on the upper edge of the nostrils.

Skull with dorsoventral flattening (Fig. 8), characterized by an elevation extending from the nasal tip to the posterior part of the braincase. Postorbital constriction is prominently defined, accompanied by deep lacrimal canals. The sagittal crest is distinctive, reaching its peak at the junction with a well-developed lambdoidal crest. Tympanic bullae small. Basisphenoid pits are shallow. Third upper molar is well-developed in the female, surpassing the maxillary bone (Fig. 9). Third upper molar is less developed in the male, not extending beyond the maxillary bone (Fig. 9). Lower incisors are bilobed. Some skull measurements are shown in Table 1.

Identification.

The relatively small size (forearm <33 mm) and condylobasal length <15 mm allowed for the assignment of the denomination M. temminckii to the specimens referred to here, distinguishing them from the only known congener in Brazil (M. neglectus S. L. Williams & Genoways, 1980), whose reported distribution corresponds to the southeastern region (Gregorin et al. 2020). Molossops griseiventer Sanborn, 1941 a taxon recently validated as a full species (Ramírez-Chaves et al. 2023), has an Andean distribution in Colombia. It can be differentiated from M. temminckii by the less pronounced shape of the nasal septum. However, it is important to consider that Ramírez-Chaves et al. (2023) did not provide information on sex differences in their comparisons. The variations between M. temminckii and M. griseiventer, suggested by Ramírez-Chaves et al. (2023), could be related to sexual dimorphism, as reported in our study. These authors compared both species without considering the marked sexual dimorphism in Molossidae (Eger 2008); future studies could clarify the possible separation between M. griseiventer and M. temminckii.

Molossops sp.

Summary of captures. One female (CMARF 2146).

External measurements and weight. TLB: 71.00, TL: 21.14, LHL: 4.87, EL: 11.03, W: 6.60.

Morphological description. The dorsal pelage is chocolate brown at the tips and yellow at the base, while the coloration is slightly paler ventrally. Ears triangular, with small and triangular tragus. Antitragus broad and slightly inclined posteriorly. Snout elongated, flat, wide, and blunt, featuring a slightly prominent tip and an obtuse projection between the nasal orifices. Lips smooth and bordered by a fine fringe of hook-shaped hairs, accompanied by a tuft of bristles below the nostrils.

The skull exhibits dorsoventral flattening, with a slight elevation from the tip of the nasals to the back of the braincase. Postorbital constriction is prominently defined, accompanied by deep lacrimal canals. The sagittal crest is present but is low at the junction with the lambdoidal crest. Lambdoidal crest weakly developed. Tympanic bullae are small, and the basisphenoid pits are shallow. The third upper molar has two well-developed posterior commissures, surpassing the maxillary bone. Lower incisors are trilobed. Some skull measurements are shown in Table 1.

Identification. The presence of three-lobed lower incisors and two well-developed posterior commissures in the third upper molar, surpassing the maxillary, represent unique characteristics that differentiate this specimen from the two specimens previously assigned to Molossops temminckii or its other congener, Molossops griseiventer.