Molossus rufus E. Geoffroy, 1805

Loureiro, Livia Oliveira, Gregorin, Renato & Perini, Fernando Araujo, 2018, Diversity, morphological phylogeny, and distribution of bats of the genus Molossus E. Geoffroy, 1805 (Chiroptera, Molossidae) in Brazil, Zoosystema 40 (18), pp. 425-452 : 436

Molossus rufus E. Geoffroy, 1805

Molossus rufus E. Geoffroy, 1805: 279 .

Molossus castaneus E. Geoffroy, 1805: 279 .

Molossus ursinus Spix, 1823: 59 (type locality: Suburbis Para, Brazil).

Dysopes alecto Temminck, 1826: 231 (type locality:Brazilian lowlands).

Dysopes albus Wagner, 1843: 368 (type locality: Mato Grosso, Brazil).

Dysopes holosericeus Wagner, 1843: 368 (type locality: Rio de Janeiro, Brazil).

Molossus myosurus Tschudi, 1845: 83 (type locality: Cejaregion farm, Ostabhange der Binnencordillera, Peru).

Molossus molossus rufus – Peters 1866: 575 (name combination).

Molossus albus – Pelzeln 1883: 43 (name combination).

Molossus fluminensis Lataste, 1891: 658 (type locality: Rio de Janeiro, Rio de Janeiro, Brazil).

Molossus molossus fluminensis – Trouessart 1897: 143 (name combination).

Molossus nigricans Miller, 1902: 395 (type locality: Acaponeta, Tepic [Nayarit], Mexico).

Molossus pretiosus macdougalli Goodwin, 1956: 3 (type locality: San Blas, Tehuantepec, Oaxaca, Mexico).

Molossus ater – Goodwin 1960: 4 (not from E. Geoffroy, 1805).

EMENDED DIAGNOSIS. — Largest species of Molossus with a dark dorsal pelage varying from dark brown to blackish ( Fig. 10 ). Monochromatic dorsal hairs or, when dichromatic, with a small pale basal band covering no more than 1/4 of the total length. Dorsal hairs reaching 4.0 mm. Forearm length averaging 50.3 mm in males (47.7-55.2) and 50.0 mm in females (46.7-54.0). Greatest length of skull averaging 22.9 mm (20.8-23.8) in males and 21.3 mm (19.9-22.6) in females ( Table 1 ). Skull with inflated rostrum and elongated braincase ( Fig. 11A, C ). Mastoid process directed laterally in posterior view and occipital square-shaped with highly developed and inclined lambdoidal crests ( Fig. 11B ). High sagittal crest, particularly in males ( Fig. 11B, D ). Infraorbital foramen opening laterally in frontal view ( Fig. 11D ). Basioccipital pits with moderate depth. Triangular rostrum in frontal view ( Fig. 11D ). Pincer-like upper incisors with converging tips ( Fig. 11D ).

VARIATION. — The dorsal fur is always very dark, ranging from dark brown to blackish. In some individuals, the entire dorsal hair or just the tips are reddish brown (hence the specific epithet). In females, the sagittal and lambdoidal crests are less robust and the nasal process of the pre-maxilla, although also projecting over the nasal cavity, is less developed than in males.

DISTRIBUTION. — M. rufus is widely distributed in South America, occurring from Trinidad to Bolivia, Paraguay, Argentina, and in a large portion of Brazil ( Eger 2008) ( Fig. 12 ).

REMARKS

M. rufus resembles M. pretiosus in having dark pelage, and similar body and cranial size. However, M. pretiosus tends to be smaller ( Table 1 ). M. rufus has higher sagittal crest when compared to M. pretiosus ; the mastoid process in M. rufus is laterally oriented in posterior view ( Fig. 11B ), while it is ventrally oriented in M. pretiosus ( Fig. 2E ); and M. rufus has spatulate incisors ( Fig. 11H ) whereas they are elongated and thin in M. pretiosus ( Fig. 2G ) (although there are variation among samples).

Figures

FIG. 10. — Molossus rufus (E. Geoffroy, 1805). Photo courtesy of Dr Marco A. R. Mello (https://marcoarmello.wordpress.com).

FIG. 11. — Skull of Molossus rufus E. Geoffroy, 1805: A, dorsal view; B, posterior view; C, lateral view; D, frontal view. Scale bar: 1 mm.

FIG. 12. — Geographic range of Molossus rufus (E. Geoffroy, 1805) in Brasil. The numbers represent the localities described in Appendix 1.

FIG. 2. — Variable characters in skull morphology within Molossus E. Geoffroy, 1805 (Pallas, 1766): A, B, lateral views; C, D, ventral views; E, F, posterior view; H, G, frontal view. Numbers represents characters described in the text: 1, skull robustness; 2, sagittal crest; 3, basioccipital pits; 4, projection of the canines; 5, lambdoidal crest and occipital complex; 6, mastoid process; 7, rostrum shape; 8, infraorbital foramen; 9, upper incisors; 10, nasal process. Not to scale.