Molossus pretiosus Miller, 1902

Turcios-Casco, Manfredo A., Cardoso Claudio, Vinicius & Lee Jr, Thomas E., 2024, Back to the future: A preserved specimen validates the presence of Molossus pretiosus (Molossidae, Chiroptera) in Honduras, ZooKeys 1196, pp. 139-148 : 139

Molossus pretiosus Miller, 1902

Material examined.

Honduras • 1 ♀; Roatán, Fantasy Island Resort, Islas de la Bahía department; 16°21'30"N, 86°26'9"W; 4 m a.s.l.; 6 March 2005; Thomas Lee leg; dead specimen found on the ground; ACUNHC 1034 .

Description.

Given that the skin (ACUNHC 1034) was desiccated when discovered, no description is available for the fur. As a result, the identification of the specimen primarily relies on characteristics of the skull (Table 1 ). The rostrum is short and quadrangular in shape. There is no projection over the nasal cavity by the nasal process of the premaxilla; therefore, the nasal process is undeveloped. The skull presented a squarish occipital complex (Fig. 2A ) because of the significant size and angling of the lambdoidal crests. The skull exhibits distinct features, including a well-developed bulging braincase and sagittal crest (Fig. 2B ), as well as a deep basioccipital pit with a ridge. There is a noticeable crest between the basisphenoid and basioccipital pits. Infraorbital foramen opened laterally, when viewing from the front. Additionally, the M3 molars display cup-like structures with a V-shaped pattern (Fig. 2C ). The elongated upper incisors extend beyond the canines and the tips and are not in contact. The forearm measurement in the dried skin of the ACUNHC 1034 specimen is recorded as 45.08 mm. This measurement matches the range observed in Central American specimens (44.3-45.9 mm) ( Jennings et al. 2000).

Comparisons.

In comparison to the other species of Molossus that occur in Honduras, Molossus nigricans Miller, 1902 is larger than M. pretiosus , the FA of the former varies from 47.2-54.5 mm in females and GLS from 20.1-22.6 mm in females ( Loureiro et al. 2019). Molossus alvarezi ( González-Ruíz, Ramírez-Pulido & Arroyo- Cabrales , 2011) is medium-sized and may overlap in some measurements, but it does not have a well-developed sagittal crest; it has pincer-like upper incisors converging at the tips, and the occipital region is triangular ( González-Ruíz et al. 2011; Díaz et al. 2021). Molossus molossus (Pallas, 1766) is usually smaller with FA ranging from 36.4-42.6 mm in females and GLS from 15.6-18.6 mm in females ( Loureiro et al. 2018). In addition to the other two species that occur in Honduras, Molossus bondae J. A. Allen, 1904 and Molossus aztecus Saussure, 1860 have upper incisors as pincer-like with convergent tips, but those of M. pretiosus are larger than those of M. bondae (FA <43 mm) ( Loureiro et al. 2019; Jennings et al. 2000), and M. aztecus differs in having its basisphenoid pits with a moderate depth ( Díaz et al. 2021), and is currently only known from western Honduras ( McCarthy et al. 1993; Turcios-Casco et al. 2021).

Figures

Figure 2. Skull (A, B) and mandible (C) of Molossus pretiosus (ACUNHC 1034) from Roatan Island. A ventral view (squarish occipital complex) B dorsal view (note the well-developed bulging braincase and sagittal crest C dorsal view of the upper mandible (M 3 molars with a V-shaped pattern). Credits of the photos are to Nil Santana (ACUNHC 1034).