Micronycteris (Schizonycteris) simmonsae Siles & Baker 2020, sp. nov

Micronycteris (Schizonycteris) simmonsae sp. nov

M[icronycteris] minuta Porter et al., 2007:1210, Appendix 1

M[icronycteris] minuta Larsen et al., 2011:690 (Clade 3).

M[icronycteris] minuta Siles et al., 2013:886 (Clade 3).

Micronycteris minuta Carrera et al., 2010:11.

Zoobank No. urn:lsid:zoobank.org:act: EDA3E335-F421-4D2A-9FCF-610258617ECA

Voucher TTU 103201 (Figure 7, Table 3); adult female; preserved in ethanol with the skull removed at the Natural Science Research Laboratory, Museum of Texas Tech University (Lubbock, Texas, USA). Collected on August 9, 2004, by Robert J. Baker and collaborators (see Carrera et al., 2010 for details). Tissues deposited at the same collection (TK 135801). The specimen is well preserved.

Ecuador: Esmeraldas Province; surrounding land of the commune San Francisco de Bogotá (1.072583°N, 78.7115°W; elevation 88 m).

Three additional specimens collected from Ecuador are designated as paratypes based on genetic data and are deposited at the Natural Science Research Laboratory, Museum of Texas Tech University (Lubbock, Texas, USA). Sequenced and measured voucher TTU 103198 (tissues TK 135798); juvenile male; preserved in ethanol with the skull removed; collected on August 9, 2004, by Robert J. Baker and collaborators from the type locality. Sequenced voucher TTU 103253 (tissues TK 134785); adult female; preserved in standard skin and skull; collected on July 4, 2004, Robert J. Baker and collaborators from Bosque Protector Cerro Blanco, visitor center (2.179889°S, 80.021583 °W; elevation 22 m), Guayas Province, Ecuador. Sequenced voucher TTU 103333 (tissues TK 134860); adult female; preserved in standard skin and skull; collected on July 4, 2004, Robert J. Baker and collaborators from Bosque Protector Cerro Blanco, Rocafuerte sport club, Manantial sector (2.180778°S, 80.03175°W; elevation 22 m), Guayas Province, Ecuador.

Distribution

Endemic to Ecuador. Restricted to the western region of the Andes, Guayas and Esmeraldas provinces (Figure 1).

The epithet simmonsae, a feminine noun in the genitive case, honors the scientist Nancy B. Simmons, curator in charge of the Department of Mammalogy at the American Museum of Natural History for her important contributions to the knowledge of bat diversification, systematics, and evolution. Also for her extensive research on the genus Micronycteris, which included species descriptions and detailed accounts that were of great help for this work.

Ventral hair is paler than dorsum. In dorsal view, rostrum is short and pear-shaped (pyriform), and inflated in the region over P4, M1, and M2. Sagittal crest is low and present over the parietals. Palatine bones are long, anteriorly convergent, and the sutura palatomaxillaris is located between M1 and M2. Lower inner incisors are brachydont and bilobed. P3 and P4 are equal in size in lateral view or P3 can be slightly shorter, and P3 is rectangular or square in occlusal view. No gaps are present between the canines and I2, or between P3 and P4.

Micronycteris simmonsae also can be distinguished from its congeners based on DNA sequence data.Phylogenetically,maternal (cytb), nuclear (Fgb -I7), and paternal (Y-chromosome DBY5 and DBY7) sequences position M. simmonsae in a clade that is divergent and well supported from other members of the genus studied thus far.

Micronycteris simmonsae is a small-sized bat, similar in size to all other pale-bellied species, but less robust than M. schmidtorum. External measurements (in mm): forearm 35–36, total length 46–58, tail 11–12, foot 11–13, ear 20–23, tragus 7–8, metacarpal III 27.1, metacarpal IV 27.75, thumb 8.32, tibia 15.9, and calcar 8.18. The dorsal fur is short (~ 6 mm in the shoulder region) and bicolored with brown tips and a white base that comprises approximately less than half of each hair (white portion ~ 2.4 mm). Cranial measurements are presented in Appendix 1. Comparisons of M. simmonsae with other pale-bellied species are presented in the description section of M. tresamici (see above); thus, we focus on comparisons with M. minuta. The shape of rostrum, width of POC relative to cranium, palatine bones, and P 3 in occlusal view are similar in M. simmonsae and M. minuta. Differences can be observed in the sagittal crest, which extends from the beginning to the end of the parietals in M. simmonsae, whereas in M. minuta is either absent or, if present, it only extends over the first third, first half, or first two thirds of the parietals. In lateral view, P3 and P4 are equal in size or P3 is only slightly shorter in M. simmonsae; in M. minuta, P3 is always shorter than P4, and the width is variable: P3 is broader or equal than P 4 in individuals from northern South America and narrower or equal in individuals from southern South America. No gap between P3 and P 4 in M. simmonsae, but the presence of gap is variable in M. minuta. The basisphenoid pits are deep in M. simmonsae; in M. minuta, they are shallow in individuals from northern South America and deep in individuals from southern South America.

The karyotype has 2n = 28 and FN = 50 (Figure 4) and comprises 12 biarmed chromosome pairs, three of which have a subtelocentric morphology. The X is a medium-sized submetacentric, whereas the Y has a dot-like morphology. This karyotype is identical in M. minuta, M. sanborni, and M. tresamici and apparently is characteristic of the subgenus Schizonycteris.

Tropical rain forests located in the confluence of the ChocóDarien humid ecosystem from the north and the deciduous Peruvian coastal dry forest from the south that support high levels of diversity and endemism (Carrera et al., 2010). San Francisco de Bogotá (locality 1) is a small village located 21 km S and 14 E of San Lorenzo in northwestern Ecuador and includes primary forest, disturbed forest, fruit trees, and other plantations (Carrera et al., 2010). Bosque Protector Cerro Blanco (locality 2) is a private reserve in central western Ecuador managed by Fundación Probosque and is located 8 km W of Guayaquil city in a remnant of tropical dry forest, which protects primary and secondary forest (Carrera et al., 2010). Bats were captured during the 2004 Sowell Expedition (Museum of Texas Tech University and Museo de Zoología of the Pontificia Universidad Católica del Ecuador), and other species collected from these two localities included: Saccopteryx bilineata (localities 1, 2), Micronycteris megalotis (1, 2), Desmodus rotundus (1), Lonchorhina aurita (1), Macrophyllum macrophyllum (1), Trachops cirrhosus (1), Lophostoma brasiliense (1), L. occidentalis (1), Mimon crenulatum (1), Phyllostomus discolor (1), P. elongatus (1), P. hastatus (1), Tonatia saurophila (1), Glossophaga soricina (2), Lonchophylla concava (1), L. robusta (1), Hsunycteris thomasi (1), Carollia brevicauda (1, 2), C. castanea (1), C. perspicillata (1), Trinycteris nicefori (1), Rhinophylla alethina (1), Sturnira lilium (1, 2), S. luisi (1, 2), Artibeus fraterculus (2), A. jamaicensis (1, 2), A. lituratus (1, 2), A. rava (1), A. rosenbergi (1), Chiroderma trinitatum (1), C. villosum (2), Platyrrhinus chocoensis (1), P. dorsalis (1), P. matapalensis (1, 2), Uroderma bilobatum (1, 2), Vampyressa thyone (1), Vampyriscus nymphaea (1), Noctilio leporinus (2), Thyroptera sp. (1), Myotis albescens (1), Myotis nigricans (1, 2), M. riparius (2), M. simus (2), Eptesicus chiriquinus (1), E. innoxius (2), Lasiurus blossevillii (2), Dasypterus ega (1), Rhogeessa velilla (2), Eumops wilsoni (2), Molossus bondae (2), and Molossus molossus (2) (Carrera et al., 2010).

Micronycteris simmonsae is restricted to western Ecuador, and it is genetically divergent from M. minuta specimens from northern South America (including eastern Ecuador), Peru, and Bolivia; therefore, M. minuta (type locality Bahia, Brazil) and its junior synonyms M. hypoleuca (Colombia) and M. homezorum (Venezuela) are not valid names for this taxon and remain available if northern and southern populations prove to be taxonomically distinct.