Eumops chiribaya, Medina, César E., Gregorin, Renato, Zeballos, Horacio, Zamora, Hugo T. & Moras, Ligiane M., 2014

Medina, César E., Gregorin, Renato, Zeballos, Horacio, Zamora, Hugo T. & Moras, Ligiane M., 2014, A new species of Eumops (Chiroptera: Molossidae) from southwestern Peru, Zootaxa 3878 (1), pp. 19-36 : 27-30

Eumops chiribaya , sp. nov.

Chiribaya's Bonneted Bat Figure 4

Holotype. Dried skin, skull, and partial skeleton of an adult female ( MUSA 8493), deposited at the Museo de Historia Natural de la Universidad Nacional de San Agustín ( MUSA). The specimen was captured on 1 June 2010 by a local person and was taken to the MUSA, where it was received and prepared by Hugo T. Zamora (original number HZM 670). Tissues are deposited at MUSA. The specimen is in good condition, except by the broken lower left canine.

Type locality. El Algarrobal, 111 m; 8.4 km NE of Ilo; Ilo Province; Moquegua Department; Peru, 17º37'21.6" S, 71º16'06.6" W ( Fig. 3 ).

Etymology. The specific epithet chiribaya is given in honor of the Chiribaya culture (900–1,350 A.D.). Chiribayans were settled in the basin of the Ilo River, and expanded north to the Tambo valley (Arequipa) and the south to the Azapa valley ( Chile), including the high altitude regions, up to nearly 3,000 m of elevation. Distribution. Eumops chiribaya is known only from the type locality ( Fig. 3 ).

Diagnosis. Eumops chiribaya is distinguished from all other species of the genus by the following combination of characters: medium body size; relatively large ears (25.7 mm); dorsal coloration light olive-brown, with slightly lighter belly; dorsal hairs bicolored, with white base that conspicuously contrast with the tip; square-shaped tragus; cranium with elongated rostrum; narrow post-orbital constriction; tiny incisive foramen; basisphenoid pits rectangular, deep and separated by a narrow septum; opisthocranion curved dorsally and anteriorly; mastoid foramen present; premetacrista equal to half the length of postparacrista on M3; mandible gracile with a welldeveloped keel ( Fig. 4 ).

Description. Eumops chiribaya is a medium size species ( Table 5 ). Dorsal coloration is light olive-brown, with a lighter belly. Pelage is soft, long (6 mm taken at the level of the shoulder region) with bicolored dorsal hairs (basal third of each hair white in color). Face naked; upper lip smooth to weakly wrinkled on distal edge of snout. Nose blackish; upper border of narial region surrounded by small and pointed warts, internarial ribs covered by small, spoon-like and blackish hairs. Ears large (25.7 mm), round, blackish and joined on the forehead; upper border smooth, but the inner face with brown hairs distributed from the dermal keel to the top of the ear. Tragus square-shaped. Antitragus semicircular, wider than higher. Dorsal surface of propatagium and plagiopatagium near to forearm and dactilopatagium at basal middle of fifth metacarpal covered with short light olive-brown hairs. Feet blackish; external edges and ventral surface of the first and fifth toes of the feet covered by short hairs, silver in color, with claws covered by longer hairs of the same color. Calcar longer than feet. Uropatagium dull brown with free portion of the tail blackish.

Skull with elongated and narrow rostrum in dorsal view, and straight in profile ( Fig. 4 ). Braincase rounded, tending to be angular anteriorly; opisthocranion curved dorsally and anteriorly. Nasal process of the premaxilla well-developed. Postorbital constriction narrow. Medial sagittal crest poorly developed. Palate long and slightly wide. Medial process of posterior margin of palate bridge absent. Incisive foramina tiny, with two concentric cusps longitudinally. Mesopterygoid fossa broad and rectangular. Foramen ovale well-developed. Sphenorbital fissure narrow. Basisphenoid pits large, deep, rectangle-shaped, and separated from each other by a narrow septum. Mastoid foramen present. Premetacrista equal to half the length of postparacrista on M3. Mandible gracile with well-developed keel.

Measurements of the holotype. The external measurements (mm) and weight (g) are: total length 134; tail length 52; hindfoot length 13.5; ear length 25.7; forearm length 61.1; and weight 20.3. Measures used in the morphometric analysis are indicated in table 5.

Comparisons. Eumops chiribaya is a medium-sized member of Eumops ( Table 5 ) phylogenetically related to medium-large sized species and morphologically more similar to E. perotis and E. trumbulli ( Fig. 1 ). The smaller size distinguishes E. chiribaya from the large species E. perotis and E. trumbulli , also E. dabbenei and E. underwoodi (FA greater than 68 mm; Eger 1977).

Eumops bonariensis , E. patagonicus , E. nanus , and E. hansae (here, E. bonariensis clade) are comparatively small (FA less than 49 mm; Table 1 , Eger 1977) and differentiated in morphology and molecular data ( Fig. 1 ). E. chiribaya is also distinguished from E. bonariensis and its relatives by smooth upper lips (finely wrinkled in E. bonariensis clade), blackish pelage (light or grayish brown in E. bonariensis clade), long rostrum (shorter in E. bonariensis clade), occipital region in lateral view is mildly curved (straight in E. bonariensis clade complex and E. wilsoni — Fig. 4 ), and reduced premetacrista on M3 (long, N-shapped in E. bonariensis clade).

From the species that occur in Peru, Eumops chiribaya has similar external and cranial dimensions to E. wilsoni and E. auripendulus ( Table 5 ). Eumops auripendulus (and also E. maurus ) is easily distinguished from E. chiribaya because it has a blackish pelage (cocoa brown in E. maurus ), pointed tragus, different shape of skull, in particular, extended posterior portion of basicranium, and reduced premetacrista on M3 (V-shaped) ( Fig. 4 ). Eumops wilsoni (and also E. glaucinus ) is similar to E. chiribaya (i.e. light brown dorsal pelage, square-shaped tragus, and premetacrista on M3 slightly longer), but the shape of skull (shorter rostrum and wider post-orbital constriction) and ears relatively smaller (21.8 mm in E. wilsoni , 17-23 mm in E. glaucinus ) distinguish both species from the E. chiribaya (Fig. 5). Very deep and wide basisphenoid pits also distinguish E. chiribaya from E. auripendulus , E. glaucinus , and E. wilsoni ( Fig. 4 ).

Eumops chiribaya differs from E. perotis and E. trumbulli based on the following combination of characteristics: smaller size ( E. chiribaya has a medium body size and forearm shorter than in E. trumbulli and E. perotis - FA = 61, 65, and 79 mm, respectively); smaller ears, with ratio of length of ears/length of forearm reaching 0.42 in comparison with E. trumbulli and E. perotis , which have very developed ears (> to 0.49); basisphenoid pits are proportionally deeper in E. chiribaya than E. trumbulli and E. perotis ; and its opisthocranion is curved dorsally and anteriorly whereas it is extended posteriorly in E. trumbulli and E. perotis ( Fig. 4 ).

Natural history. Eumops chiribaya inhabits in Coastal desert of southern Peru. The holotype was captured alive by a police officer during his patrolling in the locality El Algarrobal, Moquegua, Peru. He mentioned that the bat struck the top of a gate (approximately 5 meters high) and fell on the road, allowing him to catch the specimen with his own hands.

The holotype had no ectoparasites nor showed signs of reproductive activity. The stomach content was not analyzed.

Figures

FIGURE 1. Phylogeny of Eumops. Left, Bayesian phylogeny with Molossus molossus and Tadarida brasiliensis as outgroups (number above branches are Bayesian posterior probabilities and those below are maximum-likelihood bootstrap values). Right, strict consensus of three most parsimonious trees calculated from a heuristic search of 18 taxa and 38 discrete morphological characters (number above branches indicate bootstrap values).

FIGURE 3. Map of southwestern Peru illustrating the type locality of Eumops chiribaya (star).

FIGURE 4. Dorsal, ventral, and lateral views of the skulls and lateral view of the mandibles of five species of genus Eumops from Peru, from left to right: E. chiribaya (MUSA 8493), E. auripendulus (MUSA 5995), E. wilsoni (holotype, TTU 103281), E. trumbulli (MUSM 243), and E. perotis (MUSM 6049). Scale bar = 10 mm.

Tables

TABLE 5. Comparative measurements (mm) of the holotype of Eumops chiribaya sp nov., and females of selected species of genus Eumops. Numbers include mean ± SD and ranges in brackets.

	Eumops chiribaya	E. wilsoni (N = 18)	E. glaucinus (N = 66)	E. auripendulus (N = 74)	E. trumbulli (N = 11)	E. perotis (N = 31)
GLS	23.36	23.76 ± 0.27 (23.28–24.27)	24.40 ± 0.42 (22.88–25.54)	24.68 ± 0.53 (23.51–25.94)	28.62 ± 0.44 (27.77–29.18)	32.02 ± 0.65 (30.44–33.01)
CIL	22.51	22.69 ± 0.27 (22.26–23.30)	23.37 ± 0.40 (22.27–24.27)	22.81 ± 0.48 (21.73–23.91)	27.29 ± 0.41 (26.54–27.84)	30.78 ± 0.59 (29.52–31.93)
PL	9.38	10.49 ± 0.22 (10.15–10.97)	10.71 ± 0.26 (10.01–11.56)	10.98 ± 0.26 (10.45–11.67)	12.94 ± 0.31 (12.58–13.38)	14.36 ± 0.40 (13.79–15.55)
ZB	13.23	14.02 ± 0.21 (13.57–14.27)	14.52 ± 0.31 (13.81–15.21)	14.13 ± 0.36 (13.34–14.89)	16.29 ± 0.28 (15.82–16.64)	18.22 ± 0.46 (17.25–18.90)
PB	4.55	4.87 ± 0.13 (4.63–5.19)	4.94 ± 0.17 (4.58–5.49)	4.57 ± 0.18 (4.25–5.08)	4.99 ± 0.14 (4.78–5.24)	5.41 ± 0.20 (5.02–5.96)
BB	11.59	10.96 ± 0.20 (10.60–11.30)	11.05 ± 0.34 (10.29–11.8)	10.71 ± 0.29 (10.04–11.40)	12.25 ± 0.28 (11.73–12.67)	13.27 ± 0.31 (12.59–13.73)
C-C	4.93	5.82 ± 0.24 (5.37–6.31)	5.92 ± 0.17 (5.56–6.38)	6.04 ± 0.21 (5.62–6.54)	6.76 ± 0.24 (6.29–7.04)	8.14 ± 0.33 (7.37–8.70)
MTRL	8.55	9.39 ± 0.22 (8.90–9.75)	9.60 ± 0.20 (9.20–10.04)	9.33 ± 0.19 (8.93–9.79)	11.13 ± 0.22 (10.82–11.40)	12.72 ± 0.23 (12.30–13.06)
M-M	8.40	9.82 ± 0.24 (9.39–10.20)	10.03 ± 0.29 (9.46–10.73)	9.85 ± 0.25 (9.30–10.60)	10.98 ± 0.19 (10.71–11.28)	12.54 ± 0.30 (11.86–13.03)
DENL	15.92	17.71 ± 0.33 (17.10–18.44)	18.38 ± 0.37 (17.22–19.01)	18.26 ± 0.45 (16.84–19.19)	21.21 ± 0.43 (20.64–21.79)	23.92 ± 0.48 (23.14–24.78)
MANDL	9.41	10.23 ± 0.25 (9.74–10.66)	10.49 ± 0.25 (9.98–11.09)	10.25 ± 0.28 (9.73–10.92)	11.88 ± 0.28 (11.40–12.30)	13.69 ± 0.29 (13.06–14.21)
FA	61.1	57.40 ± 1.12 (55.30–59.48)	58.60 ± 1.60 (50.40–61.32)	58.04 ± 1.51 (54.91–62.34)	69.85 ± 0.77 (68.38–70.92)	77.50 ± 2.04 (72.02–81.09)
LIV	58.02	56.90 ± 1.14 (54.94–59.20)	58.58 ± 1.47 (54.16–62.14)	57.60 ± 1.65 (52.81–62.59)	68.56 ± 0.68 (67.28–69.46)	75.51 ± 1.97 (71.65–79.84)
fal1-IV	20.66	19.22 ± 0.75 (18.03–20.59)	20.53 ± 0.75 (18.15–22.24)	21.50 ± 0.89 (19.60–23.30)	24.08 ± 0.63 (23.04–25.34)	26.96 ± 1.02 (25.30–29.03)