Myotis, Kaup, 1829

Moratelli, Ricardo, Gardner, Alfred L., Oliveira, João A. De & Wilson, Don E., 2013, Review of Myotis (Chiroptera, Vespertilionidae) from northern South America, including description of a new species, American Museum Novitates 2013 (3780), pp. 1-36 : 29-30

KEY TO VENEZUELAN AND COLOMBIAN SPECIES OF MYOTIS

1a. Fringe of hairs along the trailing edge of uropatagium present............. M. albescens

1b. Fringe of hairs along the trailing edge of uropatagium absent........................ 2

2a. Fur on dorsum of uropatagium extending along tibia to foot; fur on plagiopatagium along body distributed from elbow to tibia...................................... M. keaysi

2b. Fur on dorsum of uropatagium reaching knee or below; fur on plagiopatagium along body either absent or extremely sparse................................................ 3

3a. Dorsal fur woolly; occipital usually flattened posteriorly............................ 4

3b. Dorsal fur silky; occipital usually rounded posteriorly.............................. 5

4a. Plagiopatagium broadly attached to foot at level of toes (> 1.5 mm wide); dorsal fur 5 mm or longer; breadth across canines 3.4–3.9 mm; interorbital breadth 4.4–4.7 mm ............................................................................. M. riparius

4b. Plagiopatagium attached at ankles or extending to base of toes by a narrow band of membrane (<1.5 mm wide); dorsal fur 4 mm or shorter; breadth across canines 4.1–4.5 mm; interorbital breadth 4.8–5.0 mm.......................................... M. simus

5a. Dorsal fur strongly bicolored; forearm length usually 33 mm or shorter; third metacarpal long relative to forearm (ratio 3MC/FA greater than 0.96)................ M. nesopolus

5b. Dorsal fur slightly bicolored or unicolored; forearm length usually 33 mm or longer; third metacarpal short relative to forearm (ratio 3MC/FA usually less than 0.95)............ 6

6a. Frontals steeply sloping; parietals rounded posteriorly in lateral view; greatest length of skull, including incisors, 14.4 mm or more................................ M. oxyotus

6b. Angle of slope of frontals variable; parietals flattened and dorsal profile inclined forward; greatest length of skull, including incisors, 14.2 mm or less......................... 7

7a. Dorsal pelage bicolored, ranging from dark to medium brown, with burnished tips.......................................................................... M. handleyi

7b. Dorsal pelage unicolored, ranging from medium to pale brown, lacking burnished tips. 8

8a. Forearm length 35.0 mm or less; frontals comparatively steeply sloping..... M. nigricans

8b. Forearm length 36.0 mm or more; frontals not steeply sloping............. M. caucensis