Micronycteris, Gray, 1866

Siles, Lizette & Baker, Robert J., 2020, Revision of the pale-bellied Micronycteris Gray, 1866 (Chiroptera, Phyllostomidae) with descriptions of two new species, Journal of Zoological Systematics and Evolutionary Research 58 (4), pp. 1411-1431 : 16-17

4.5 | Key to Micronycteris species

1. Ventral fur color paler than dorsal fur (gray,buff, or white) …………2

1'. Ventral fur color dark, as the dorsal fur ………………………………………8

2. Lower incisors hypsodont. All lower premolars very robust and similar in size, or p3 slightly smaller. Rostrum is triangular in dorsal view …………………..…………………………………………………… M. schmidtorum

2'. Lower incisors brachydont. Lower premolars less robust with p3 slightly (p2≈p4>p3), or much smaller than p2 and p4 (p2>p4>p3). Rostrum not triangular in dorsal view ……………………………………………3

3.Ventral fur color gray or buff,but never pure white.……………………4

3'. Ventral fur color pure white, at least in the neck and chest ……… 6

4. Tall cranium, with a slope of 30°-35° in relation to the rostrum. Mastoid breadth shorter than zygomatic breadth MB<ZB ……………… ……………………………………………………………………………………… M. brosseti

4'. Cranium not tall, with a slope less than 26° in relation to the rostrum. Relationship between zygomatic and mastoid breadths variable …………………………………..…………………………………………………………… 5

5. Low sagittal crest over the parietals. Basisphenoid pits deep. P3 and P4 similar in size, or P3 slightly shorter. Restricted to western Ecuador …………...……………………………………………………… M. simmonsae

5’. Sagittal crest absent or, if present, it is over the first third, first half, or first two thirds of the parietals. Basisphenoid pits shallow or deep (shallow in individuals from northern South America). P3 shorter than P4 ……………………………........…………………………… M. minuta

6. Short palatines, with the sutura palatomaxillaris between M2 and M3. Rostrum elongated and pyriform. ……………………………… M. yatesi

6'. Longer palatines, with the sutura palatomaxillaris between M1 and M2. Short rostrum, variable shape. ………………………………………… 7

7. Rostrum short-oval. Low sagittal crest over the first third or first half of the parietals.P3 oval in occlusal view.Central American distribution ………………………………………………………………………… M. tresamici

7'. Rostrum short-pyriform.Sagittal crest absent.P3 round in occlusal view. Distribution in Brazil ………………………………………… M. sanborni

8. Lower incisors hypsodont ……………………………………………………… 9

8'. Lower incisors non-hypsodont ……………………………………………… 10

9. Forearm longer than 40.9 mm. Prominent nuchal crest. Medial upper incisors (I1) long and narrow …………………………………… M. hirsuta

9'. Forearm shorter than 39.5 mm. Nuchal crest absent. Medial upper incisors (I1) short and robust. Endemic to St. Vincent Island …………… ………………………………………………………………………………………… M. buriri

10. Forearm longer than 37.7 mm. Known from the Amazonian lowlands (NE Peru) …. …………………………………………………………… M. matses

10'. Forearm shorter than 37.1 mm …………………………………………… 11

11. Greatest length of skull longer than 20.8 mm. Endemic to northwestern Ecuador ……………………………………………………… M. giovanniae

11'. Greatest length of skull shorter than 20.1 ……………………………………………………………………… M.megalotis complex*

* Includes M. microtis and M. megalotis that are currently undefined.