Molossus molossus (Pallas, 1766)

García, Franger J., Ochoa-G, José, Poma-Urey, José L., Miller, Bruce W., Falcão, Fábio C. & del Valle Alvarez, Martín Roberto, 2024, Expanding the knowledge of the bat fauna of the Brazilian Caatinga: new geographical records of molossid bats (Chiroptera, Molossidae) for the Chapada Diamantina region, with taxonomic notes, ZooKeys 1210, pp. 333-371 : 333-371

Molossus molossus (Pallas, 1766)

Summary of captures.

13 females ( CMARF 2157–2169) and one male ( CMARF 2171).

External measurements and weights.

Females: TLB: 102.38 (100.00–115.00), TL: 40.68 (36.00–45.00), LHL: 6.68 (5.95–7.88), EL: 11.92 (10.00–16.00), W: 11.30 (10.00–13.00). Male: TLB: 105.00, TL: 30.00, LHL: 6.68, EL: 12.70, W: 12.00.

Morphological description.

Rostrum narrow with a developed keel (Fig. 11 ). Dorsal hairs are notably bicolored in some females, with broad white bases and dark brown or chocolate hues tips (Fig. 11 ). Dorsal pelage is slightly bicolored in the male, with a pale brown base and a broader dark brown or chocolate hues distal band. Ventral coloration is paler brown, subtly contrasting the dorsal side in all specimens. Length of dorsal hairs at the shoulders: 2–3 mm in females and 3 mm in the male.

Upper incisors with parallel tips, projecting anteriorly from the rostrum. Infraorbital foramen anteriorly positioned. Nasal process present. The occipital complex is triangular (Fig. 10 ). Basioccipital pits are absent in some females and in the male, while they are present but barely visible in other females. Sagittal and lambdoidal crests are present but with different degrees of development, showing the maximum degree in the male. The mastoid process developed and oriented ventrally. Presence of a pair of bilobed lower incisors. Some skull measurements are shown in Table 2 .

Identification.

The rostrum is narrow with a developed keel, the dorsal hairs notably bicolored to slightly bicolored, the infraorbital foramen anteriorly positioned, and the occipital complex triangular in shape, differentiate the individuals of this species from their morphologically closest related congeners: Molossus aztecus and M. currentium ( Gregorin et al. 2011; Loureiro et al. 2018 a, 2018 b).

Figures

Figure 10. A Molossus aztecus (CMARF 2147) B Molossus molossus (CMARF 2158) C Moloussus currentium (CMARF 2154), collected in the Caatinga (northeastern Brazil), showing differences in the shape of the upper incisors (left), and the occipital complex shape in the posterior region of the skulls (right).

Figure 11. A, B Molossus molossus (CMARF 2159) and C, D Molossus rufus (CMARF 2182) A, C dorsal and ventral views of the skull in two species of Molossus collected in the Caatinga, northeastern Brazil B, D individuals of M. molossus and M. rufus photographed in the field (not to scale). Scale bar 5 mm.