Sturnira bakeri, Velazco, Paul M. & Patterson, Bruce D., 2014

Velazco, Paul M. & Patterson, Bruce D., 2014, Two new species of yellow-shouldered bats, genus Sturnira Gray, 1842 (Chiroptera, Phyllostomidae) from Costa Rica, Panama and western Ecuador, ZooKeys 402, pp. 43-66 : 45-49

Sturnira bakeri sp. n.

Synonymy.

Sturnira lilium : Carrera et al. 2010: 18 (part)

Sturnira luisi : Carrera et al. 2010: 18 (part)

S[turnira]. new species 2: Velazco and Patterson 2013: 687

Holotype.

Adult female, deposited at the Museo de Zoología of the Pontificia Universidad Católica del Ecuador (QCAZ 14635), collected on 16 July 2004 by J. Sebastián Tello (original field number JST 487). The body is preserved in alcohol with the skull removed and cleaned. The body and skull are in good condition. Frozen tissues are deposited at Texas Tech University (TK 135127).

Type locality.

Palmales, Reserva Militar Arenillas, El Oro, Ecuador, approximately 3°40'27.4"S, 80°06'20"W, 49 m (Figure 2).

Paratypes.

An adult female (QCAZ 9737) caught by Peter A. Larsen (original field number PAL 92) and an adult male (QCAZ 9739) caught by Peter A. Larsen (original field number PAL 93), both collected on 16 July 2004 at Quebrada Seca, Fuerte Militar Arenillas (7.1 km W and 12.5 km S of the Military Base), El Oro, Ecuador, approximately 3°39'24.1"S, 80°10'56.2"W, 43 m (Figure 2). Both paratypes are preserved in alcohol. Frozen tissues are deposited at Texas Tech University (TK 135040 and TK 135051 respectively).

Distribution.

Sturnira bakeri is known from only the two localities in southwestern Ecuador represented by the hypodigm (Figure 2, Appendix). Their proximity to the Peruvian border opens the possibility that Sturnira bakeri is also present in northwestern Peru.

Etymology.

The name bakeri honors our friend Dr. Robert J. Baker, who has made enormous contributions to our understanding of bats, particularly to the evolution of Neotropical phyllostomids. Robert’s numerous contributions, both to the literature and to scientific discourse, and his productive and generous mentoring of students make him a professional paragon for each of us.

Measurements.

External and craniodental measurements are presented in Table 1.

Diagnosis and description.

Sturnira bakeri is a medium-size yellow-shouldered bat (FA 43.0-45.0 mm; GLS 22.7 mm; CIL 21.1 mm; Table 1) with a slender rostrum and a globular braincase (Figures 3-4). The dorsal fur is pale brown. Dorsal hairs are tetracolored with a short, whitish base (approximately 10% of the length of each hair), a long, pale brown band (approximately 40% of each hair), a long, pale gray band (approximately 40% of each hair), and a short dark brown terminal band (approximately 10% of each hair). The ventral fur is pale gray. Ventral hairs are tricolored with a short, pale gray base (approximately 10% of each hair), a long, pale brown subterminal band (approximately 45% of each hair), and a long, pale gray terminal band (approximately 45% of each hair). The fur is short and woolly, approximately 5 mm long between the shoulders and 5 mm on the chest. The proximal portion of the forearm (roughly 50% of the shaft just distal to the elbow) is sparsely furred with short hairs. The wing membranes are dark brown. The dorsal surfaces of the femur, tibia, and feet are densely covered with long hairs. The IV metacarpal is shorter than the III metacarpal.

The skull of Sturnira bakeri has a globular braincase with a slender rostrum and well-developed sagittal crest (Figures 3-4). The basisphenoid pits are shallow and divided by a low midline septum. The sphenorbital fissure is oval (Figure 5). The anterior process of the glenoid fossa is absent (Figure 6). The clinoid processes are well developed (Figure 7), and the proximal end of the stylohyoid is expanded.

Like most species of Sturnira , Sturnira bakeri has a dental formula of I2/2, C1/1, P2/2, M3/3 = 32 teeth. The upper inner incisor (I1) is bicuspidate with a small lateral cusp (Figure 8). The I1 is procumbent and is at least twice the height of the I2. Anteroposterior length of P3 is less than that of P4, and crown height of P3 is slightly less than that of P4. P4 has a small distal cusp. The anteroposterior length of M1 is larger than that of M2. The paracones of M1 and M2 are shorter than their metacones. The direction of the premetacrista of M1 is oblique to the upper alveolar plane. The M3 is ovoid in shape and has two labial cones (cusps). The first and second lower incisors (i1 and i2) are tricuspidate and are subequal in height. The lower canine covers 25% of the occlusal area of i2. The lower canines are laterally divergent, shafts are slanted outward. Anteroposterior length of p2 exceeds that of p4, and crown height of p2 is slightly more than that of p4. The protoconid, hypoconid, metaconid, and entoconid are present in m1 and m2. The paraconid is present and well developed in m1 but absent in m2. The lingual cuspids (metaconid and entoconid) of m1 and m2 are well defined and separated by a deep notch (Figure 9). The m3 is small and only poorly defined, but its protoconid, metaconid, and entoconid are visible.

Comparisons.

Comparisons were made with sister species ( Sturnira parvidens ) ( Velazco and Patterson 2013) and with other species of the genus ( Sturnira ludovici , Sturnira luisi , and Sturnira parvidens ) that occur in sympatry with Sturnira bakeri . External and craniodental measurements for Sturnira bakeri and the compared species are provided in Tables 1 and 2. Sturnira bakeri can be easily distinguished from Sturnira parvidens by its longer forearm and longer greatest length of skull (Tables 1-2). Sturnira bakeri , Sturnira ludovici , and Sturnira luisi overlap somewhat in size (Tables 1-2) but are unambiguously distinguished by pelage and craniodental characteristics.

Externally, the dorsal pelage between the shoulders of Sturnira bakeri , Sturnira luisi , and Sturnira parvidens is short (4.0-6.0 mm) whereas it is long (10 mm) in Sturnira ludovici . Individual dorsal hairs are tetracolored in Sturnira bakeri and Sturnira ludovici whereas they are bicolored in Sturnira luisi and Sturnira parvidens . The overall appearance of the dorsal pelage is pale brown in Sturnira bakeri and Sturnira luisi , whereas it is dark brown in Sturnira ludovici and reddish in Sturnira parvidens . Ventrally the hairs are short (4.0-6.0 mm) and tricolored in Sturnira bakeri , Sturnira ludovici , and Sturnira parvidens , but short (4.0-6.0 mm) and bicolored in Sturnira luisi . The ventral fur is pale gray in Sturnira bakeri , whereas it is dark gray in Sturnira luisi , dark brown in Sturnira ludovici , and reddish in Sturnira parvidens . Shoulder glands (epaulettes) are conspicuous in Sturnira bakeri , Sturnira ludovici , Sturnira luisi , and Sturnira parvidens . The trailing edge of the uropatagium is covered by short hairs (4.0-5.0 mm) in Sturnira bakeri , Sturnira luisi , and Sturnira parvidens , whereas the uropatagium is covered by long hairs (7.0-9.0 mm) in Sturnira ludovici . The proximal portion of the forearm (roughly 50% of the shaft just distal to the elbow) is sparsely furred with short hairs in Sturnira bakeri and Sturnira luisi , whereas it is well furred with short hair in Sturnira ludovici and Sturnira parvidens . The dorsal surfaces of the femur and tibia are densely covered with long hairs in Sturnira bakeri , whereas they are densely covered with short hairs in Sturnira ludovici , sparsely covered with long hairs in Sturnira parvidens , and sparsely covered with short hairs in Sturnira luisi . The dorsal surfaces of the feet are densely covered with long hairs in Sturnira bakeri and Sturnira parvidens , whereas they are densely covered with short hairs in Sturnira ludovici or sparsely covered with short hairs in Sturnira luisi . The IV metacarpal is shorter than the III metacarpal in Sturnira bakeri and Sturnira parvidens , whereas the IV metacarpal is equal to the III metacarpal in Sturnira ludovici and Sturnira luisi .

Cranially, the rostrum of Sturnira bakeri , Sturnira ludovici , and Sturnira luisi is slender, whereas it is broad in Sturnira parvidens . The zygomatic arches are straight in Sturnira bakeri and Sturnira luisi , whereas they are bowed outward in Sturnira ludovici and Sturnira parvidens . The basisphenoid pits are shallow and divided by a low midline septum in Sturnira bakeri and Sturnira ludovici , whereas they are shallow and divided by a high septum in Sturnira luisi and deep and divided by a high septum in Sturnira parvidens . The sphenorbital fissure is oval in Sturnira bakeri , Sturnira ludovici , and Sturnira parvidens , whereas it is subcircular in Sturnira luisi (Figure 5). The anterior process of the glenoid fossa is absent in Sturnira bakeri , whereas it is well developed in Sturnira luisi and Sturnira parvidens (Figure 6). Some specimens of Sturnira ludovici lack the anterior process of the glenoid fossa (TTU 102461) while in others (TTU 102457) it is well developed. The clinoid processes are present and well developed in Sturnira bakeri and Sturnira ludovici , whereas they are absent in Sturnira luisi (Figure 7). Some specimens of Sturnira parvidens lack clinoid processes (ROM 97412; TTU 84608) while others (ROM 99284) possess them. The proximal end of the stylohyoid is expanded in Sturnira bakeri , Sturnira ludovici , and Sturnira parvidens , whereas it is narrow in Sturnira luisi .

Dentally, two labial cusps are present in M3 in Sturnira bakeri , Sturnira luisi and Sturnira parvidens , whereas only one labial cusp is present Sturnira ludovici . The i1 and i2 are tricuspidate in Sturnira bakeri , Sturnira luisi , and Sturnira parvidens , whereas they are bicuspidate in Sturnira ludovici . The metaconid and entoconid of m1 and m2 are well defined and separated by a deep notch in Sturnira bakeri , Sturnira luisi , and Sturnira parvidens , whereas they are poorly defined and are not separated by a deep notch in Sturnira ludovici (Figure 9).

Natural history.

The area surrounding the Fuerte Militar Arenillas is relatively xeric and surrounded by primary dry forest, secondary forest, and plantations of crops ( Carrera et al. 2010). No other information is available.