ii. Key to species of Pteropodidae (* denotes records in Sumatra but not in BBSL)

1.1. No claw on 2nd finger............................................................................... 2 (genus Eonycteris)

1.2. Claw on 2nd finger.................................................................................. 3

2.1. FA 59–80 mm; the crown of 1st upper premolar is about equal to the crown of 2nd upper incisor; 1st premolar sometimes absent.............................................................................. Eonycteris spelaea

2.2. FA 75–83 mm; the crown of 1st upper premolar is distinctly larger than the crown of 2nd upper incisor... Eonycteris major *

3.1. Tail present but short................................................................................ 4

3.2. Tail absent or insignificant........................................................................... 14

4.1. One pair of lower incisors; FA 57–64 mm .................................................... Penthetor lucasi

4.2. Two pairs of lower incisors........................................................................... 5

5.1. Upper postcanine teeth flat on crown surface and relative weak; five upper postcanine teeth (four in some individuals)... 6 (genus Rousettus)

5.2. Upper postcanine teeth sharp and strong; three or four pairs of upper postcanine teeth............................. 8

6.1. Back hairless; wings joined in spinal midline............................................ Rousettus spinalatus *

6.2. Back well furred; wings not joined in spinal midline....................................................... 7

7.1. The last lower postcanine teeth nearly circular; FA 78–87 mm ........................... Rousettus amplexicaudatus

7.2. The last lower postcanine teeth elliptic (length 1.5–2.0 to width); FA 78–87 mm ............... Rousettus leschenaultii

8.1. Ear edge and finger whitish (in adult only); four pairs of upper postcanine teeth................................. 9 (genus Cynopterus)

8.2. Ear edge and finger not whitish; three pairs of upper postcanine teeth......................................... 13 (genus Dyacopterus *)

9.1. Peg-like cusp on the 3rd and 4th lower postcanine teeth; FA 68–76 mm ....................... Cynopterus horsfieldii

9.2. No peg-like cusp on the lower postcanine teeth........................................................... 10

10.1. Ear length <18 mm ................................................................................ 11

10.2. Ear length> 18 mm ................................................................................ 12

11.1. Ears straight or slightly notched at posterior edge; adults generally irritable and noisy; FA 59–73 mm .................................................................................................. Cynopterus brachyotis

11.2. Ears curved at posterior edge; adults generally calm and quiet; FA 52–62 mm .................... Cynopterus minutus

12.1. Head reddish; FA 62–79 mm ............................................................ Cynopterus sphinx

12.2. Head blackish; FA 73–83 mm ..................................................... Cynopterus titthaecheilus *

13.1. FA 75–83 mm; smaller head (CBL 33.9–36.1 mm, MH 14.5–15.4 mm)...................... Dyacopterus spadiceus *

13.2. FA 81–92 mm; bigger head (CBL 36.5–37.1 mm, MH 15.4–16.3 mm) a ........................ Dyacopterus brooksi *

14.1. Small-medium sized, FA <65 mm ..................................................................... 15

14.2. Large, FA> 100 mm ................................................................................ 22 (genus Pteropus)

15.1. Yellow/white spots on face and wings; FA 40–45 mm ..................................... Balionycteris maculata

15.2. No spots on face and wings.......................................................................... 16

16.1. Head light brown, light grayish brown, buffy brown or orange brown......................................... 17

16.2. Head dark, dark gray or dark grayish brown............................................................. 20

17.1. Strong muzzle; short tongue, nostrils strongly tubular; ear edge darker and is contrasts to the rest part of pinna; postcanine teeth 4/5......................................................................................... 18 (genus Megaerops)

17.2. Narrow muzzle; long tongue; nostrils not tubular; ear edge is similar color to the rest part of pinna; postcanine teeth 5/6... 19 (genus Macroglossus)

18.1. TB> 15 mm; first phalanges of 4th and 5th digits brown; FA 49–60 mm ...................... Megaerops ecaudatus

18.2. TB <15 mm; first phalanges of both 4th and 5th digits whitish; white tufts on neck in some individuals known in peninsular Malaysia and Borneo populations, possible for Sumatra but unconfirmed; FA 45–52 mm ....... Megaerops wetmorei *

19.1. Internarial groove does not reach upper lip; FA 41–50 mm ................................. Macroglossus sobrinus

19.2. Internarial groove reaches upper lip and splits the lip into two; FA 39–44 mm ................. Macroglossus minimus *

20.1. One pair of lower incisors; head gray or dark grayish/reddish brown; FA 42–46 mm ................. Aethalops alecto

20.2. Two pairs of lower incisors; face nearly black and in sharp contrast with the underparts of body; FA 39–49 mm ....... 21 (genus Chironax)

21.1. Ear tip round, EL ≤ 11 mm; BM ≤ 15 g; FA 40–44 mm .................. Chironax melanocephalus round-eared form

21.2. Ear tip pointed, EL> 12 mm; BM ≥ 19 g; FA 41–47 mm ................. Chironax melanocephalus tipped-eared form

22.1. FA> 170 mm; BM> 680 g; interfemoral membrane narrowed in center; premolars without ledges.... Pteropus vampyrus

22.2. FA <170 mm; interfemoral membrane not narrowed in center; premolars with ledges; recorded in western offshore islands only............................................................................................. 23

23.1. Back blackish; FA 125–165 mm ........................................................ Pteropus melanotus *

23.2. Back not blackish; FA 105–150 mm; BM <300 g ........................................ Pteropus hypomelanus *