Research Article |
Corresponding author: Rui-Chang Quan ( quanrc@xtbg.ac.cn ) Corresponding author: Song Li ( lis@mail.kiz.ac.cn ) Academic editor: Raquel López-Antoñanzas
© 2020 Guogang Li, Ye Htet Lwin, Bin Yang, Tao Qin, Phouthong Phothisath, Kyaw-Win Maung, Rui-Chang Quan, Song Li.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Li G, Lwin YH, Yang B, Qin T, Phothisath P, Maung K-W, Quan R-C, Li S (2020) Taxonomic revision and phylogenetic position of the flying squirrel genus Biswamoyopterus (Mammalia, Rodentia, Sciuridae, Pteromyini) on the northern Indo-China peninsula. ZooKeys 939: 65-85. https://doi.org/10.3897/zookeys.939.31764
|
The flying squirrel genus Biswamoyopterus (Rodentia: Sciuridae: Pteromyini) was once considered to contain three species, Biswamoyopterus biswasi from northeastern India, B. laoensis from central Laos and B. gaoligongensis from southwest China, all identified from morphological characteristics of one or two specimens. However, based on similar morphological characteristics of two samples of the genus Biswamoyopterus collected recently from northern Laos and northern Myanmar, and the small genetic distances on mitochondrial DNA and nuclear DNA between them, the results strongly support these two samples as representatives of the same species. The phylogenetic analyses strongly support Biswamoyopterus as an independent genus of Pteromyini, as a sister group to Aeromys. Biswamoyopterus biswasi is distributed in the northern Indo-China peninsula, where it is exposed to a series of threats, such as intense hunting activity, illegal trade, and rapid habitat loss; this should warrant its classification as critically endangered according to the International Union for Conservation of Nature (IUCN) Red List criteria. Here, the molecular data for genus Biswamoyopterus and two new specimen records from northern Laos and northern Myanmar are presented.
Biswamoyopterus, flying squirrel, Indo-China peninsula, taxonomic revision.
Flying squirrels (Mammalia: Rodentia: Sciuridae: Pteromyini), occurring in northern coniferous forests to the tropical lowlands of North America and Eurasia, are great masters of gliding locomotion using well-developed membrane structures (
Taxonomic hypotheses of various authors regarding Pteromyidae/Pteromyini.
|
|
|
|
|
---|---|---|---|---|
Aeretes | Aeretes | Aeretes | Aeretes | |
Aeromys | Aeromys | Aeromys | Aeromys | |
Belomys | Belomys | Belomys | Belomys | |
Biswamoyopterus | Biswamoyopterus | Biswamoyopterus | ||
Eoglaucomys | Eoglaucomys | Eoglaucomys | ||
Eupetaurus | Eupetaurus | Eupetaurus | Eupetaurus | Eupetaurus |
Glaucomys | Glaucomys | Glaucomys | ||
Hylopetes | Hylopetes | Hylopetes | Hylopetes | Hylopetes |
Iomys | Iomys | Iomys | Iomys | |
Petaurillus | Petaurillus | Petaurillus | Petaurillus | |
Petaurista | Petaurista | Petaurista | Petaurista | Petaurista |
Petinomys | Petinomys | Petinomys | Petinomys | Petinomys |
Pteromys | Pteromys | Pteromys | Pteromys | |
Pteromyscus | Pteromyscus | Pteromyscus | Pteromyscus | |
Trogopterus | Trogopterus | Trogopterus | Trogopterus | Trogopterus |
Many studies on the molecular phylogeny of Pteromyini genera have been performed since 2000 (Oshida 2000a, b, 2001, 2004;
Since 2014, the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (CAS-SEABRI), has conducted several biodiversity expeditions to the northern Indo-China peninsula (
Localities of Biswamoyopterus specimens. The black square represents B. biswasi, ZSI 20705 (Saha, 1981); the black triangle represents B. laoensis, NUoL FES. MM.12.163 (
All samples used in this study were obtained by the CAS-SEABRI expeditions on the northern Indo-China peninsula, with export permits (no. L/2020-0001/MA-0004/MA) issued by Biotechnology and Ecology Institute, Ministry of Science and Technology of Lao PDR, and permission (1567/XTBG/2017) issued by the Forest Research Institute, Forest Department, Ministry of Environmental Conservation and Forestry of Myanmar.
Twelve flying squirrel samples (two of Biswamoyopterus and ten of Petaurista) were collected from northern Myanmar and northern Laos during the expedition of 2014–2018 (see Suppl. material
According to the taxonomic assignments of Wilson and Reader (2005), pelage and skull characteristics can be discriminated using traditional methods and compared with those of other genera using specimens (Appendix I) retained in the Kunming Natural History Museum of Zoology, Kunming Institute of Zoology, Chinese Academy of Sciences (
Comparison of five specimens of genus Biswamoyopterus. M644 was measured (millimeters) in this study, others were derived from
Specimen | B. biswasi | B. gaoligongensis | B. gaoligongensis | B. laoensis | Biswamoyopterus sp. M644 |
---|---|---|---|---|---|
Sex | male | male | unknown | female | unknown |
Locality | Northeastern India | Southwestern China | Southwestern China | Central Laos | Northern Myanmar |
Head and body length | 405 | 440 | – | 455 | 540 |
Tail length | 605 | 520 | – | 620 | 605 |
Hind feet length | 78 | 75 | – | 74.5 | 71 |
Ear length | 46 | 47 | 46 | 52 | 43 |
ONL | 72.4 | 69.75 | 71.11 | 74.39 | 74.22 |
CBL | 70.1 | 66.37 | 67.73 | 70.99 | 69.88 |
MB | – | 30.72 | 33.5 | 30.79 | 27.15 |
ZB | 47.5 | 48.41 | 48.3 | 47.72 | 47.09 |
ZH | – | 4.61 | 4.58 | 4.86 | 5.03 |
BB | – | 33.86 | 34.46 | 32.84 | 33.68 |
BH | – | 22.9 | 24.15 | 22.55 | 22.37 |
RB | – | 19.61 | 19.62 | 17.04 | 19.66 |
NL | 20.9 | 19.35 | 20.7 | 22.57 | 21.83 |
MWN | – | 13.15 | 12.51 | 13.37 | 13.23 |
IOB | 19 | 15.75 | 16.38 | 14.06 | 14.29 |
POB | – | 18.87 | 20.55 | 17.19 | 16.87 |
LIF | 6.4 | 5.65 | 5.86 | 5.85 | 6.21 |
LBP | – | 20.08 | 22.01 | 23.83 | 22.37 |
PPL | – | 28.72 | 29.68 | 28.77 | 29.96 |
LAB | 15.5 | 14.68 | 14.57 | 17.33 | 15.03 |
WAAM | – | 35.88 | 36.76 | 35.96 | 36.96 |
IBG | – | 6.52 | 6.76 | 5.01 | 6.41 |
MYTL | 15.5 | 15.92 | 16.23 | 16.33 | 16.53 |
GPB | – | 18.26 | 18.61 | 19.37 | 19.98 |
WPFM | – | 8.58 | 8.03 | 8.05 | 8.34 |
MRTL | – | 15.24 | 15.41 | 15.33 | 15.75 |
ML | – | 44.44 | 46.53 | 45.36 | 44.67 |
MH | – | 27.1 | 27.37 | 29.78 | 29.66 |
PL | 34.7 | 32.6 | 32.87 | – | 35.08 |
DL | 15.7 | 13.7 | 15.03 | – | 15.30 |
OB | 24.6 | 26.17 | 26.5 | – | 28.42 |
FL | 28.6 | 27.66 | 30.63 | – | 30.27 |
BB Breadth of braincase,
BH Braincase height,
CBL Condylobasal length,
DL Diastema length,
FL Frontal length,
GPB Greatest palatal breadth,
IBG Inter bullae gap,
IOB Interorbital breadth,
LAB Length of auditory bulla,
LBP Length of bony palate,
LIF Length of the incisive foramina,
MB Mastoid breadth,
MH Mandible height,
ML Mandible length,
MRTL Mandibular tooth row length,
MWN Maximum width of nasals,
MYTL Maxillary tooth row length,
NL Nasal length,
OB Orbit breadth,
ONL Occipitonasal length,
PL Palate length,
POB Postorbital breadth,
PPL Postpalatal length,
RB Rostrum breadth,
WAAM Width of auditory bullae across the external auditory meati,
WPFM Width of the bony palate at the first upper molar,
ZB Zygomatic breadth,
ZH Zygomatic height,
P Premolars,
M Molars.
Superscript (PX, MX) upper premolars and upper molars, and Subscript (PX, MX) lower premolars and lower molars.
In addition, measurements of the head and body length, tail length, hind foot length, and ear length were taken and compared with the original measurements labeled on the skins by the collectors. The skull measurements of M644 are listed in Table
Total genomic DNA was extracted from tissue using a DNeasy Blood & Tissue kit (Qiagen, Shanghai, China). PCR mixtures contained approximately 100 ng of template DNA, 1 μL (10 pmol) of each primer, 5 μL of 10× reaction buffer, 2 μL of dNTPs (2.5 mM of each), and 2.0 U of Taq DNA polymerase, in a total volume of 50 μL. Reactions were carried out in a Veriti Thermal Cycler (Applied Biosystems, Carlsbad, CA, USA) and always included a negative control. Segments of the nuclear genes encoding the inter photoreceptor retinoid-binding protein (IRBP) and mitochondrial 12S and 16S ribosomal DNA of flying squirrels were amplified using PCR with universal primers described previously (
DNA sequences were edited using the DNASTAR 5.0 (DNASTAR Inc.) program and aligned using the CLUSTALW algorithm in MEGA 6.06, with default parameters (
Phylogenies using the combined mitochondrial and nuclear DNA data from our collection and GenBank were reconstructed using maximum likelihood in RaxML version 8 (
Morphometrical data are presented in Table
The upper surface of the head is deep reddish brown, the muzzle is brown, the rim of the eyes is brown, the cheeks are reddish brown with occasional whitish hairs on their lower parts, the ears are black with few hairs but tufts with long, whitish hairs at the base, the back of the neck is reddish brown, and the throat and chin show whitish grey extending to both sides of the neck.
The back is mainly reddish brown, but is scattered with many white tips, especially on the shoulders and hips; individual hairs are variable in color but usually comprise the following components: whitish at the tip, reddish brown in the mid-part, and whitish grey at the base. The anterior margin of the forearms is black-brown. The chest is yellowish grey, the center of the abdomen is yellowish white, and the anus area is dull yellowish. The upper part of the membrane is reddish brown and the underpart whitish, extending to yellowish brown on the edge. The tail is cylindrical, reddish brown anteriorly, but gradually darkening towards the tip, so its posterior part is blackish brown, and the underpart area of the tail base is brown-grey. The fore and hind feet are covered with black hairs; however, the hind feet have denser hair than the fore feet, and both have dark hairless pads.
Comparison of ear tufts of all known Biswamoyopterus specimens. The red arrow indicates the anterior tufts, and the yellow arrow indicates the posterior tufts A B. biswasi, ZSI 20705 B B. gaoligongensis,
The skull is large, the frontal part is significantly depressed, the rostrum is short and wide, the anterior edge of the nasals is slightly beyond the surface of the incisors with a slight arc-shape, the incisive foramen is developed, the palatine posterior edge has an arc-shaped depressed deformation, the pterygoid is strong and the pterygoid fossa wider, the bulla is developed with numerous septa (> 10) in a complex honeycomb pattern, the orbital regions are large and there is an incision on the edge of each orbit, the postorbital process is strong and curves down a little, the zygomatic plate is slant, the zygomatic arch is stronger with lower connection to the squamosal, the mastoid process is comparatively smaller, but the occipital condyle is strong.
The skulls (first three rows), left maxillary (the fourth rows) and left mandibular teeth (the last rows) of all known Biswamoyopterus specimens A B. biswasi, ZSI 20705 B B. gaoligongensis,
The mandible is strong, with the coronoid process developed, and the condylar process has a developed articular surface; the angular process is developed and curved towards the inside at its bottom. The upper incisors are strong and positioned vertically downwards; their outer surfaces are yellowish, without any orange. P3 is cone-shaped and on the inside of the front of P4; overall, the crown surface of P4 appears as a triangle with three well-developed cusps on the labial side and one large cusp on the lingual side, and its labial side length is slightly longer than those of M1, M2, and M3. M1 and M2 are approximately equal in size; both have two well-developed cusps on the labial side, and one large cusp and one smaller cusp on the lingual side. There is a smaller cusp on the posterior transverse ridge of P4, M1, and M2. Compared with P4, M1, and M2, M3 is the smallest; its lingual side cusp is larger than the cusp on the labial side, and its later crown surface becomes a U-shape, with a small depression in its center.
The posterior margin of the palatal bones relative to the posterior margin of M3 (dotted line) and shape of the preglenoid process (arrow) of all known Biswamoyopterus specimens A B. biswasi, ZSI 20705 B B. gaoligongensis,
The outer surface of the lower incisors is yellowish, the same as for the upper incisors; however, the inside part of the inner surface sinks deeply, making the outside margin sharp. From P4 to M3, the teeth enlarge gradually, and there are two labial and lingual cusps on each of them (the later lingual cusp of M3 becomes a ridge); there is also a smaller cusp between, and slightly internal to, the two labial cusps on each of them. Different levels of depression occur in the centers of the crown surfaces of P4, M1, M2, and M3, with the largest in M3.
The sample L35 from northern Laos shares the same pelage color of the tuft hair at the base of the ear and side of the neck (Figure
Comparison of five specimens of genus Biswamoyopterus. M644 and L35 were described in this study, others were derived from
Specimen | B. biswasi, ZSI 20705, ♂ |
B. gaoligongensis, |
B. laoensis, NUoL FES. MM.12.163, ♀ | Biswamoyopterus sp. M644 | Biswamoyopterus sp. L35 |
---|---|---|---|---|---|
Locality | Northeastern India | Southwestern China | Central Laos | Northern Myanmar | Northern Laos |
Size | Relatively small | Relatively small | Large | Large | Large |
Dorsal coloration | Morocco-red speckled with white | Reddish brown speckled with white | Dark reddish brown speckled with whitish grey | Reddish brown speckled with whitish | Dark reddish brown speckled with whitish grey |
Ventral Coloration | Light colored | Pale orange and marked with numerous, black, discontinuous lines | White | ||
White | Yellowish-white | ||||
Coloration of tail beyond the uropatagium | Partly colored tail with a dark tip | Black | Reddish brown with a brown-grey tip | ||
Pale smoky grey with a dark tip | Black | ||||
Ear tufts | Bicolored or white | Black | White | White | |
White | The anterior tufts are black, and the posterior tufts are basally white and terminal black | ||||
NL | Short | Long | Long | – | |
Short | Shorter | ||||
Outer margin of the nasal bone, orbital margin of the frontal bone, and post-orbital margin of the frontal bone vs. midline of the skull | Inclined | Almost | More | Inclined | – |
Postorbital processes | Large | Large | Relatively small | Large | – |
Preglenoid process | Forward protruding | Almost flat | Almost flat | Almost flat | – |
Sutures of frontal and squamosal bone | Almost flat | Bulge | Almost flat | Almost flat | – |
Auditory bulla | Smaller | Large | Relatively small | – | |
Relatively small | Relatively small | ||||
Posterior margin of the palatal bones | Concave forward | Flat | Concave forward | – | |
The central point just meets the posterior margin of M3 | The central point lies in front of the posterior margin of M3 | The central point lies behind the posterior margin of M3 | The central point lies just a little in front of the posterior margin of M3 | ||
M1 and M2 | Feeble metacone and hypocone, outline of M1 and M2 is sub-triangular | Most developed metacone and hypocone, outline of M1 and M2 is sub-square | Second developed metacone and hypocone, outline of M1 and M2 is sub-rectangle | Second developed metacone and hypocone, outline of M1 and M2 is sub-rectangle | – |
M1 and M2 | Second developed hypoconid | Most developed hypoconid | Feeble hypoconid | Feeble hypoconid | – |
Maximum Likelihood and Bayesian Inference analyses of the combined sequences of nuclear gene IRBP (1070 bp), mitochondrial 12S (823 bp), and 16S (535 bp) ribosomal DNA recovered similar tree topologies. The results showed that Eupetaurus, Aeromys, and Biswamoyopterus (sample M644 from Putao, northern Myanmar, and L35 from Louang Namtha, northern Laos) as a reciprocally monophyletic clade (Figure
For the nuclear gene IRBP, the range of original intergeneric (14 genera excluding the genus Biswamoyopterus) variation was 0.51–5.47% (Table
Average genetic distances (%) for nuclear IRBP-encoding sequences between the groups of studied flying squirrel species; intraspecific variations of genetic distances are also provided for each species.
mel | tep | pea | cin | fim | vol | pha | hor | fus | phi | kin | ele | pul | set | ans | xan | Bis | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Aeretes melanopterus (mel) | |||||||||||||||||
Aeromy tephromelas (tep) | 2.86 | ||||||||||||||||
Belomys pearsonii (pea) | 1.37 | 2.86 | |||||||||||||||
Eupetaurus cinereus (cin) | 2.68 | 2.16 | 3.03 | ||||||||||||||
Eoglaucomys fimbriatus (fim) | 4.09 | 4.01 | 4.19 | 3.74 | |||||||||||||
Glaucomys volans (vol) | 5.18 | 4.90 | 5.00 | 4.64 | 3.47 | ||||||||||||
Hylopetes phayrei (pha) | 3.94 | 4.20 | 3.76 | 4.20 | 3.13 | 3.66 | |||||||||||
Iomys horsfieldi (hor) | 3.92 | 4.01 | 3.76 | 3.84 | 2.69 | 2.95 | 2.60 | ||||||||||
Petaurista alborufus (fus) | 4.36 | 4.27 | 4.82 | 4.27 | 4.27 | 4.73 | 4.19 | 4.28 | |||||||||
Petaurista philippensis (phi) | 3.77 | 4.08 | 4.39 | 3.77 | 3.67 | 4.49 | 4.09 | 3.67 | 1.06 | ||||||||
Petaurillus kinlochii (kin) | 4.18 | 4.19 | 4.19 | 3.91 | 1.89 | 3.38 | 2.42 | 2.16 | 4.46 | 3.97 | |||||||
Petaurista elegans (ele) | 4.75 | 4.95 | 5.38 | 4.75 | 4.44 | 4.44 | 4.76 | 4.24 | 2.18 | 1.46 | 4.54 | ||||||
Pteromyscus pulverulentus (pul) | 1.28 | 2.77 | 1.46 | 2.59 | 3.92 | 4.91 | 3.85 | 3.66 | 4.74 | 3.88 | 3.91 | 4.85 | |||||
Petinomys setosus (set) | 4.28 | 4.65 | 4.38 | 4.10 | 3.03 | 3.92 | 2.87 | 2.69 | 4.82 | 4.08 | 2.77 | 4.86 | 4.10 | ||||
Pteromys volans (ans) | 4.00 | 3.91 | 3.83 | 3.91 | 4.18 | 5.08 | 4.29 | 4.47 | 4.99 | 4.90 | 4.55 | 5.47 | 3.75 | 4.56 | |||
Trogopterus xanthipes (xan) | 0.51 | 3.21 | 1.54 | 3.03 | 4.38 | 5.37 | 4.11 | 4.11 | 4.65 | 3.98 | 4.37 | 4.86 | 1.46 | 4.56 | 4.01 | ||
Biswamoyopterus sp. (bis) | 3.06 | 1.57 | 3.26 | 2.52 | 4.14 | 5.04 | 4.35 | 3.69 | 4.74 | 4.29 | 4.18 | 5.27 | 2.77 | 4.64 | 4.14 | 3.36 | |
Intraspecific variations | n/c | n/c | n/c | n/c | n/c | n/c | n/c | n/c | n/c | 0.13 | n/c | n/c | n/c | n/c | n/c | n/c | 0.09 |
For the mitochondrial 16S ribosomal DNA sequences, the range of original intergeneric variation was 2.9–14.6% (Table
Average genetic distances (%) for 16S ribosomal DNA sequences between the groups of studied flying squirrel species; intraspecific variations of genetic distances are also provided for each species.
mel | tep | pea | cin | fim | vol | pha | alb | hor | fus | hai | yun | phi | kin | ele | pul | set | ans | xan | Bis | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Aeretes melanopterus (mel) | ||||||||||||||||||||
Aeromy tephromelas (tep) | 9.5 | |||||||||||||||||||
Belomys pearsonii (pea) | 6.5 | 11.6 | ||||||||||||||||||
Eupetaurus cinereus (cin) | 10.4 | 8.2 | 11.5 | |||||||||||||||||
Eoglaucomys fimbriatus (fim) | 11.5 | 11.6 | 12.4 | 11.8 | ||||||||||||||||
Glaucomys volans (vol) | 9.7 | 9.8 | 12.2 | 11.3 | 8.7 | |||||||||||||||
Hylopetes phayrei (pha) | 11.1 | 11.7 | 12.5 | 12.5 | 10.8 | 8.5 | ||||||||||||||
Hylopetes alboniger (alb) | 10.9 | 11.4 | 12.2 | 12.3 | 10.5 | 8.4 | 2.9 | |||||||||||||
Iomys horsfieldi (hor) | 9.8 | 9.7 | 10.3 | 11.0 | 9.2 | 7.6 | 7.3 | 7.5 | ||||||||||||
Petaurista alborufus (fus) | 11.3 | 10.9 | 12.4 | 12.1 | 13.2 | 11.6 | 10.6 | 11.1 | 10.5 | |||||||||||
Petaurista hainana (hai) | 12.2 | 11.8 | 12.4 | 11.3 | 13.4 | 11.3 | 11.7 | 11.3 | 10.1 | 7.6 | ||||||||||
Petaurista yunanensis (yun) | 11.7 | 11.6 | 12.9 | 11.1 | 12.7 | 11.0 | 10.3 | 10.2 | 9.8 | 6.1 | 2.3 | |||||||||
Petaurista philippensis (phi) | 12.4 | 11.8 | 13.9 | 12.4 | 12.5 | 11.2 | 11.0 | 11.1 | 10.3 | 7.6 | 2.7 | 1.9 | ||||||||
Petaurillus kinlochii (kin) | 9.4 | 10.6 | 11.0 | 11.5 | 9.0 | 7.4 | 7.1 | 8.0 | 5.6 | 11.2 | 9.7 | 8.8 | 9.9 | |||||||
Petaurista elegans (ele) | 11.9 | 13.0 | 12.6 | 12.5 | 13.4 | 13.0 | 10.4 | 10.0 | 10.9 | 7.9 | 6.5 | 6.6 | 6.8 | 10.5 | ||||||
Pteromyscus pulverulentus (pul) | 8.0 | 11.1 | 7.8 | 11.5 | 13.6 | 12.3 | 13.8 | 13.6 | 11.4 | 12.4 | 13.3 | 12.6 | 13.6 | 10.8 | 12.7 | |||||
Petinomys setosus (set) | 11.7 | 11.2 | 12.9 | 12.7 | 8.4 | 10.6 | 8.9 | 8.6 | 10.1 | 12.9 | 13.3 | 12.1 | 12.6 | 9.0 | 11.7 | 14.6 | ||||
Pteromys volans (ans) | 10.2 | 10.5 | 10.9 | 10.6 | 10.5 | 10.9 | 12.2 | 11.7 | 10.1 | 12.4 | 10.9 | 10.7 | 11.2 | 8.3 | 12.2 | 11.6 | 11.4 | |||
Trogopterus xanthipes (xan) | 2.9 | 10.4 | 6.1 | 10.4 | 12.2 | 10.7 | 10.9 | 10.9 | 9.6 | 11.3 | 12.2 | 11.7 | 12.4 | 9.2 | 11.4 | 8.0 | 12.1 | 10.6 | ||
Biswamoyopterus sp. (bis) | 8.9 | 5.2 | 8.9 | 8.0 | 8.9 | 9.3 | 9.9 | 9.6 | 8.8 | 11.0 | 12.3 | 11.1 | 11.1 | 9.5 | 12.8 | 10.9 | 11.2 | 10.3 | 8.5 | |
Intraspecific variations | n/c | n/c | n/c | n/c | n/c | 3.3 | 5.1 | n/c | n/c | n/c | n/c | n/c | 0.4 | n/c | 0.4 | n/c | n/c | 0.6 | n/c | 0.6 |
According to morphological comparisons of our samples and those from previous studies (
It was further implied by the molecular evidence that samples L35 and M644 belonged to the same species, with the smallest nuclear and mitochondrial DNA genetic distance among interspecific variations for any of the studied flying squirrel species (Tables
The molecular phylogenetic analysis strongly supported Biswamoyopterus as an independent genus within Pteromyini, acting as a sister group to Aeromys (Figure
During the expedition of 2014–2018, only two samples of Biswamoyopterus were found. We therefore propose that Biswamoyopterus should be classified as critically endangered on the IUCN Red List, due to a series of threats on the Indo-China peninsula that include intense hunting, illegal trade, and rapid habitat loss (
This work was conducted at the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (CAS-SEABRI), and the Kunming Institute of Zoology, Chinese Academy of Sciences (
Specimens examined (IOZ, Institute of Zoology, Chinese Academy of Sciences; GDEI, Guangdong Entomological Institute;
Belomys:
Table S1. GenBank numbers of sequences that were analyzed in this study
Data type: molecular data
Figure S1. Photograph of specimen L35 from northern Laos
Data type: multimedia