2021 SIMMONS ET AL.: NEW SPECIES OF MYOTIS 13 
Myotis nimbaensis is similar in size and general coloration to the widespread species M. 
welwitschii, but these taxa can be easily distinguished because M. nimbaensis completely lacks 
the prominent black spots seen on the face and patagia of M. welwitschii (figs. 3-6). Color of 
the pinnae is also different—bright orange to coppery red with a black edge in M. welwitschii 
compared to pale orange brown with no black edge in M. nimbaensis. The thumb in M. wel- 
witschii is bright orange whereas it is brown in M. nimbaensis. Both species are strongly dichro- 
matic with black wing membranes and orange along the digits and forearm, but pigmentation 
of the plagiopatagium near the body and hind legs is different in the two species. Myotis wel- 
witschii has a broad band of orange along the side of the body that extends anteriorly past the 
elbow to run along the forearm and posteriorly to the ankle, so black pigmentation is limited 
to the more distal and posterior portions of the plagiopatagium. In contrast, the orange is much 
less extensive and the black is more extensive in M. nimbaensis,; the black pigmentation 
approaches the body wall, extending anteriorly into the plagiopatagium behind the humerus 
and posteriorly to the tibia in M. nimbaensis, so there is no broad band of orange along the 
body in that species. The uropatagium in M. welwitschii is also bright orange whereas it is 
darker and more brownish in M. nimbaensis, There are additional differences in features of the 
dorsal and ventral pelage—the dorsal fur in M. welwitschii is bicolored (black at base and oth- 
erwise coppery red) rather than being tricolored as in M. nimbaensis, and M. welwitschii has 
unicolored ventral pelage (whitish tinged with coppery red) rather than the distinctive tricol- 
ored ventral fur in seen in M. nimbaensis. 
Craniodental measurements (table 1) suggest overall similarity of M. nimbaensis with M. 
welwitschii; small differences in a few dimensions are not interpretable given the small sample 
sizes. Both species have lambdoidal crests that are weakly developed but clearly visible, and 
moderately well-developed sagittal crests in both sexes, The dentition of M. welwitschii includes 
two very small anterior upper premolars that are both included in the toothrow; P3 is smaller 
than P2, but P3 is not displaced lingually as it is in M. nimbaensis. 
Myotis tricolor is a widespread species that shows considerable morphometric variation across 
its range (Koopman, 1989, 1994; Taylor, 2000; Monadjem et al., 2010). Myotis nimbaensis is 
roughly equivalent in overall size (e.g., forearm length and body mass) to the largest individuals 
of M. tricolor reported in the literature, although none of the specimens of M. tricolor that we 
measured were as large as M. nimbaensis. The only known specimen of M. tricolor from West 
Africa—a male from Liberia referred to that species by Koopman (1989)—is much smaller than 
M. nimbaensis, having a forearm length of 46.0 mm compared to 52.4 mm for the male paratype 

FIGURE 4. Fur color and banding in Myotis nimbaensis (AMNH 2795839, holotype). A, View of the dorsal fur 
showing the overall bright orange coloration; creamy white bands on the hairs proximal to the bright orange 
fur tips are visible on the lower right near the leg where the fur has been somewhat disturbed. B, Close-up of 
dorsal fur over the lower back showing tricolored fur in a spot on the center left where the fur has been slightly 
teased apart; where the fur is undisturbed, the banding of individual hairs is not visible. C, dorsal fur over 
lower back clearly showing the tricolored banding in an area where the fur has been separated by blowing. 
D, Ventral fur over torso showing overall paler coloration than dorsal fur, and tricolored banding of the hairs 
with less orange at the tips. E, Ventral fur over left side of the thorax showing bicolored banding (lack of a 
black basal band) near the wing membrane. 
