[Mammalogy • 2024] Callosciurus concolor & Tamiops barbei • Lost in Synonymy: Integrative Species Delimitation reveals Two unrecognized Species of Southern Asian Tree Squirrels (Rodentia: Sciuridae: Callosciurinae)

  

 the skins of (A) Callosciurus caniceps (NHMUK 41.1817, lectotype);
live images of (B) C. caniceps caniceps taken by Natthaphat Chotjuckdikul (Te’) in Bangkok, Thailand;
(C) C. caniceps bimaculatus taken by Pattaraporn Vangtal in Railay Bay Beach, Krabi, Thailand; and
(D) C. concolor taken by Cheong Weng Chun in Fraser’s Hill, Pahang, Malaysia.

in Hinckley, Maldonado, Tamura, Leonard & Hawkins, 2024. 

DOI: doi.org/10.3897/vz.74.e133467

Abstract

We present a comprehensive integrative taxonomic review of Callosciurus caniceps and Tamiops mcclellandii as they are currently defined. This review combines published molecular evidence, craniodental morphometrics, pelage and bacular variation, evaluations of potential hybrid zones using museum specimens and citizen science photographs, and, for C. caniceps, bioacoustic evidence. Our findings lead to the recognition of two species that had been lost in synonymy and highlight future perspectives on species delimitation in Sciuridae. By comparing phenotypic differentiation across climatic and vegetation transitions and contextualizing our results with the evolutionary history of our study systems, we provide insights into distribution, ecogeographical patterns, and speciation drivers in Southeast Asian vertebrates.

Keywords: Baculum, bioacoustics, biodiversity, citizen science, Mammalia, morphometrics, Southeast Asia, speciation, taxonomy

Taxonomic revision: 

Based on our findings, which unite molecular phylogenetic (Hinckley et al. 2023a), morphological evidence described below and in previous studies (Pocock 1923; Moore and Tate 1965; Hayashida et al. 2006), and bioacoustic data (in C. caniceps sensu lato), we conclude that the populations of Callosciurus caniceps sensu lato inhabiting Sundaland, and Tamiops mcclellandii sensu lato populations to the east of the Himalayas and Arakan range, should be recognized as distinct species. We revalidate the specific status of Callosciurus concolor (Blyth, 1855) and Tamiops barbei (Blyth, 1847), as these names represent the earliest descriptions of these separately evolving lineages. Additionally, we provide emended diagnoses and detailed species comparisons for both taxa and their sister species.

Dorsal and ventral views of the skins of (A) Callosciurus caniceps (NHMUK 41.1817, lectotype); live images of (B) C. caniceps caniceps taken by Natthaphat Chotjuckdikul (Te’) in Bangkok, Thailand; (C) C. caniceps bimaculatus taken by Pattaraporn Vangtal in Railay Bay Beach, Krabi, Thailand; and (D) C. concolor taken by Cheong Weng Chun in Fraser’s Hill, Pahang, Malaysia.

Callosciurus caniceps (Gray, 1842)

Common name: Northern gray-bellied squirrel

กระรอกปลายหางดำเหนือ

Callosciurus concolor (Blyth, 1855)

Common name: Southern gray-bellied squirrel

กระรอกปลายหางดำใต้

Tamiops mcclellandii (Horsfield, 1839)

Common name. Himalayan striped squirrel

กระเล็นขนปลายหูสั้น

Tamiops barbei (Blyth, 1847)

Common name. Southeast Asian striped squirrel

กระเล็น

 Arlo Hinckley, Jesús E. Maldonado, Noriko Tamura, Jennifer A. Leonard and Melissa T. R. Hawkins. 2024. Lost in Synonymy: Integrative Species Delimitation reveals Two unrecognized Species of Southern Asian Tree Squirrels (Rodentia: Sciuridae: Callosciurinae). Vertebrate Zoology. 74: 683-707. DOI: doi.org/10.3897/vz.74.e133467

[Mammalogy • 2024] Spermophilus vorontsovi • Traditional Multilocus Phylogeny fails to fully resolve Palearctic Ground Squirrels Genus Spermophilus (Rodentia: Sciuridae: Marmotini) Relationships but reveals A New Species endemic to West Siberia

Spermophilus vorontsovi

Simonov, Lopatina, Titov, Ivanova, Brandler, Surin, Matrosova, Dvilis, Oreshkova, Kapustina, Golenishchev & Ermakov, 2024

  DOI: 10.1016/j.ympev.2024.108057

Highlights: 

• The first multi-locus and complete taxon sampling phylogeny of Palaearctic ground squirrels.

• Four major clades diverged during the Late Miocene.

• The main speciation events took place during the Calabrian stage of the Pleistocene.

• A new species from West Siberia is discovered and described.

Abstract

Previous efforts to reconstruct evolutionary history of Palearctic ground squirrels within the genus Spermophilus have primarily relied on a single mitochondrial marker for phylogenetic data. In this study, we present the first phylogeny with comprehensive taxon sampling of Spermophilus via a conventional multilocus approach utilizing five mitochondrial and five nuclear markers. Through application of the multispecies coalescent model, we constructed a species tree revealing four distinct clades that diverged during the Late Miocene. These clades are 1) S. alaschanicus and S. dauricus from East Asia; 2) S. musicus and S. pygmaeus from East Europe and northwestern Central Asia; 3) the subgenus Colobotis found across Central Asia and its adjacent regions and encompassing S. brevicauda, S. erythrogenys, S. fulvus, S. major, S. pallidicauda, S. ralli, S. relictus, S. selevini, and S. vorontsovi sp. nov.; and 4) a Central/Eastern Europe and Asia Minor clade comprising S. citellus, S. taurensis, S. xanthoprymnus, S. suslicus, and S. odessanus. The latter clade lacked strong support owing to uncertainty of taxonomic placement of S. odessanus and S. suslicus. Resolving relationships within the subgenus Colobotis, which radiated rapidly, remains challenging likely because of incomplete lineage sorting and introgressive hybridization. Most of modern Spermophilus species diversified during the Early–Middle Pleistocene (2.2–1.0 million years ago). We propose a revised taxonomic classification for the genus Spermophilus by recognizing 18 species including a newly identified one (S. vorontsovi sp. nov.), which is found only in a limited area in the southeast of West Siberia. Employing genome-wide single-nucleotide polymorphism genotyping, we substantiated the role of the Ob River as a major barrier ensuring robust isolation of this taxon from S. erythrogenys. Despite its inherent limitations, the traditional multilocus approach remains a valuable tool for resolving relationships and can provide important insights into otherwise poorly understood groups. It is imperative to recognize that additional efforts are needed to definitively determine phylogenetic relationships between certain species of Palearctic ground squirrels.

 

Keywords: Species tree, Riverine barrier, MIG-seq, Marmotini, North Eurasia

Spermophilus vorontsovi 

Evgeniy Simonov, Natalia V. Lopatina, Sergey V. Titov, Anastasiya D. Ivanova, Oleg V. Brandler, Vadim L. Surin, Vera A. Matrosova, Alisa E. Dvilis, Nataliya V. Oreshkova, Svetlana Yu. Kapustina, Fedor N. Golenishchev and Oleg A. Ermakov. 2024. Traditional Multilocus Phylogeny fails to fully resolve Palearctic Ground Squirrels (Spermophilus) Relationships but reveals A New Species endemic to West Siberia. Molecular Phylogenetics and Evolution. 195, 108057. DOI: 10.1016/j.ympev.2024.108057

[Mammalogy • 2022] Tamiops minshanica • A New Species of Tamiops (Rodentia, Sciuridae) from Sichuan, China

 Tamiops minshanica

Liu, Tang, Murphy, Liu, Wang, Wan, Liao, Tang, Qing, Chen & Li, 2022

DOI: 10.11646/zootaxa.5116.3.1

 

Abstract

During a small mammal survey in Wanglang National Natural Reserve, Sichuan, China in August–October 2018, we collected four specimens of an Asiatic striped squirrel (genus Tamiops) that could not be assigned morphologically to any described species. Phylogenetic analyses of CYTB and nuDNA sequences strongly supported them in the genus Tamiops. The p-distances of CYTB between these individuals and other species of Tamiops ranged from 17.4 to 19.1%. Morphologically, they differed from their congeners, including T. maritimus, T. mcclellandii, T. rodolphii, and T. swinhoei by pelage, skull, and baculum characteristics. Based on the results of morphological comparisons and molecular analyses, we describe the four specimens as the new species Tamiops minshanica sp. nov.

Keywords: Mammalia, Asiatic striped squirrels, baculum, molecular phylogeny, morphology, morphometrics, new species, Sichuan, systematics, Tamiops, taxonomy

Summer pelage of Tamiops minshanica sp. nov.

Shaoying Liu, Mingkun Tang, Robert W. Murphy, Yinxun Liu, Xuming Wang, Tao Wan, Rui Liao, Keyi Tang, Jiao Qing, Shunde Chen and Song Li. 2022. A New Species of Tamiops (Rodentia, Sciuridae) from Sichuan, China. Zootaxa. 5116(3); 301-333. DOI: 10.11646/zootaxa.5116.3.1

[Mammalogy • 2020] Ancient Divergence Driven by Geographic Isolation and Ecological Adaptation in Forest Dependent Sundaland Tree Squirrels (Genus Sundasciurus)

Sundasciurus spp.

in Hinckley, Hawkins, Achmadi, et al., 2020. 

DOI: 10.3389/fevo.2020.00208

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A surprising amount of hidden phylogenetic diversity exists in the small to medium size, drab colored squirrels of the genus Sundasciurus. This genus is endemic to Sundaland and the Philippines, where it is widespread. An earlier revision of this genus found that the high elevation ‘populations’ of the widespread, lowland slender squirrel (S. tenuis) were different species. Previous phylogenies based on mitochondrial cytochrome b sequences also suggested that the widespread, lowland Low’s squirrel (S. lowii) and the narrow endemic Fraternal squirrel (S. fraterculus) are not reciprocally monophyletic. Additionally, deep divergences have been identified between lineages within Low’s squirrel that date to the early Pliocene. Here we focus on evaluating the relationships and differences within and between populations of these two nominal species using whole mitochondrial genome sequences, nuclear intron sequences, and morphology. We reassess the taxonomy of this group, revalidate the species status of Robinson’s squirrel (Sundasciurus robinsoni Bonhote, 1903) support the species level recognition of the Natuna squirrel (Sundasciurus natunensis Thomas, 1895) and identify three other lineages that require further study. We estimate times of divergence and integrate geologic history to find that most of the divergences are pre-Pleistocene, and thus predate the Pleistocene flooding of Sundaland. Biogeographic, and ecological factors may have played a more important role than climatic factors in generating these patterns. While divergence in allopatry seems to be the main process driving speciation in lowland Sundaland squirrels (Sundasciurus), ecomorphological and behavioral adaptations in this clade suggest an important role of niche divergence.

Keywords: Sundasciurus, mammal, Borneo, biogeography, speciation, systematics, rodent, Sciuridae

Sundasciurus lowii from Sepilok, Sabah.

 photo: Mojito La

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Figure 6. Dorsal, palatal, and lateral views of the holotype skulls of Sundasciurus lowii (NHM76.5.2.14), Sundasciurus natunensis (NHM94.9.28.40) and Sundasciurus robinsoni (NHM3.2.6.55). Given the highly damaged state of the holotype skull of Sundasciurus fraterculus (NHM95.1.9.12), the type of Sundasciurus fraterculus siberu (NHM47.1488) is shown instead for the sake of comparison. All pictures are at the same scale.

Figure 1. Map of Sundaland showing the distribution of the different subspecies of the Low-Fraternal squirrel species complex, with dots indicating sample collection locations of specimens included in the morphometric analyses. Samples are colored according to the four highly supported major clades recovered in the mitogenome-based phylogenies of Figures 2, 3. Populations indicated by a red circle have been considered S. l. natunensis but the morphological data in this study suggests they are more similar to S. l. lowii. Populations indicated with a green square have been considered S. l. lowii but the morphological data in this study suggests these they are more similar to S. l. natunensis. Molecular evidence from these populations is needed to clarify their taxonomic status. Populations included in the morphological analyses but not the genetic analyses are indicated in gray.

Sundasciurus robinsoni (Bonhote, 1903) – Robinson’s squirrel

Sciurus robinsoni Bonhote (1903):24.

—Type locality. Bukit Besar, Nawngchik, Patani, Peninsular Thailand, 2500 ft.

Holotype. BMNH 3.2.6.55, skull, skin, adult female, collected 30 August 1901 by C. H. Robinson and N. Annandale

Subspecific Taxonomy

Sundasciurus robinsoni robinsoni (Bonhote, 1903)

Sciurus robinsoni alacris Thomas, 1908e: 306.—Type locality. Selangor-Pahang border, Malaya, 3000ft.

Sciurus seimundi Thomas and Wroughton, 1909:440.—Type locality. Kundur Island, Riau Islands

Sundasciurus robinsoni balae (Miller, 1903)

Sciurus balae Miller, 1903:14.—Type locality. Tana Bala, Batu Islands, Sumatra

Sciurus piniensis Miller, 1903:14.—Type locality. Pulo Pinie, Batu Islands, Sumatra

Sciurus humilis Miller, 1913:24.—Type locality. Kateman river, East Sumatra

Sundasciurus robinsoni vanakeni (Robinson and Kloss, 1916)

Sciurus vanakeni Robinson and Kloss, 1916:270.—Type locality. Barong Bharu, Korinchi, Sumatra, 4000 ft.

Distribution: Malay Peninsula, Sumatra, and Batu and Rhio Archipelagos. The subspecies S. r. robinsoni and S. r. balae have been recorded from 0–610 m, on the Malay Peninsula and Rhio and Sumatra and Batu, respectively, while S. r. vanakeni has been recorded between 900–1372 m on Mount Kerinci.

Sundasciurus natunensis (Thomas, 1895)- Natuna squirrel.

Sciurus lowii natunensis Thomas, 1895:26.

—Type locality. “Sirhassen Island” (Serasan), Natuna Islands.

Holotype. BMNH 94.9.28.40, skull, skin, adult male, collected 23 September 1893 by A. H. Everett.

Distribution: Southern Natuna islands (only recorded in Sirhassen Island), and possibly in west Borneo. Despite discrete characters such as postorbital processes and tail shape of the latter populations closely resemble S. natunensis, we currently consider the taxonomic status of west Borneo populations as incertae sedis given the intermediate phenotypic position of these among S. natunensis and S. lowii shown in the PCA and DAPC and the lack of genetic evidence. Genetic data from these, southern Sumatra and northern Natuna populations is needed to clarify the taxonomy and distribution of this group.

Sundasciurus lowii (Thomas, 1895) - Low’s squirrel.

Sciurus lowii Thomas, 1895: 253.

—Type locality. “Lumbidan, on the mainland opposite Labuan”, Sarawak, Borneo.

Holotype. BMNH 76. 5. 2. 14., skull, skin, adult male, collected by H. Low (unknown date).

Subspecific Taxonomy

Sundasciurus lowii lowii (Thomas, 1895)

Sundasciurus lowii bangueyae (Thomas, 1908)

Sciurus lowii bangueyae Thomas, 1908:387.— Type locality. “Banguey Island” (Banggi)

Sundasciurus lowii lingungensis (Miller, 1901)

Sciurus lingungensis Miller, 1901:123.—Type locality. Lingung Island, Near Bunguran Island, Natuna Islands

Distribution: S. l. lowii is present in Borneo, S. l. bangueyae in Banggi and Balambangan islands, (and possibly Malawali island as well) and S. l. lingungensis in the Northern Natunas (recorded in Bunguran, Lingung and Laut islands).

Taxonomic Notes: 

Corbet and Hill (1992) pointed out that geographical variation in Sundasciurus lowii sensu lato is slight. Many of the currently recognized subspecies are not morphologically distinct from others. We consider Sundasciurus robinsoni balae and Sundasciurus robinsoni vanakeni valid subspecies based on their ventral coloration and craniodental differentiation (Figure 5 and Supplementary Figure S3). We synonymize former Sundasciurus lowii humilis with Sundasciurus robinsoni balae due to external resemblance (ventral grayish coloration in limbs). We also synonymize based on external resemblance (lack of ventral grayish coloration in limbs) Sundasciurus lowii seimundi with Sundasciurus robinsoni robinsoni. Finally, we consider Sundasciurus lowii lingungensis and Sundasciurus lowii bangueyae valid subspecies given their craniodental differentiation (Figure 5 and Supplementary Figure S3).

Molecular species delimitation analyses suggest the presence of three species in Borneo within S. lowii (in Sabah, Sarawak and East Kalimantan). However, phenotypic divergence seems to be slight and the fine scale distribution of the morphs is unknown. The only Sarawak sample included in the PCA was clustered separately but close to Sabah + east Kalimantan, that largely overlapped. Regarding the DAPC, only east Kalimantan samples were differentiated from the remaining overlapping populations. Relative size of interorbital breadth seems to differentiate a small number of Sarawak specimens from the remaining S. lowii, but these samples are clustered very close to the other S. lowii. Sarawak specimens also seem to have darker fur than Sabah and East Kalimantan S. lowii and a lack of blond tips on the tail, which are only observed in Sabah populations. We consider these populations unconfirmed candidate species (Padial et al., 2010) until a better molecular and morphological sampling is performed in terms of geographic coverage and number of specimens included.

As pointed out by Hawkins et al. (2016a) the two subgenera, Aletesciurus and Sundasciurus, proposed by Moore (1958) are not supported as reciprocally monophyletic groups. The discrete characters (presence of sagittal crest, skull size, and shape of anterior-mesial lobe of auditory bullae) described as distinguishing subgenera were not valid for all species. For instance, the Palawan mountain squirrel (Sundasciurus rabori) belongs to Aletesciurus but lacks a sagittal crest and has an intermediate antero-mesial lobe and skull size (40.9-43.6 mm) among both subgenera (Heaney, 1979; Hawkins et al., 2016a). The northern Palawan tree squirrel (Sundasciurus juvencus) shows an antero-mesial lobe that resembles that of the subgenus Sundasciurus despite being assigned to Aletesciurus. Finally, different species of the subgenus Sundasciurus such as S. lowii, S. tahan or S. altitudinis have skulls that reach sizes (41–43 mm) that overlap with those of S. rabori (authors unpublished data). Although these discrete characters do not support the subgenera Aletesciurus and Sundasciurus, Heaney (1979) found support for them in his morphometric analyses. Molecular phylogenies suggest that there are 5–6 major phylogenetic lineages within Sundasciurus, which correspond to monophyly in the subgenus Aletesciurus (which contains 3 divergent clades), and paraphyly in the subgenus Sundasciurus (which also contains 2–3 divergent clades) (Den Tex et al., 2010; Hawkins et al., 2016a). The lack of universally valid diagnostic features and the phylogenetic evidence from this and previous studies demonstrate that current Sundasciurus subgeneric classification is invalid, so we synonymize Aletesciurus with Sundasciurus.

Arlo Hinckley, Melissa T. R. Hawkins, Anang S. Achmadi, Jesús E. Maldonado and Jennifer A. Leonard. 2020. Ancient Divergence Driven by Geographic Isolation and Ecological Adaptation in Forest Dependent Sundaland Tree Squirrels. Front. Ecol. Evol. DOI: 10.3389/fevo.2020.00208

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[PaleoMammalogy • 2019] Petaurista tetyukhensis • The First Fossil Petaurista (Mammalia: Sciuridae) from the Russian Far East and Its Paleogeographic Significance

Petaurista tetyukhensis  Tiunov & Gimranov, 2019

Petaurista leucogenys Temminck, 1827

DOI: 10.1016/j.palwor.2019.05.007 

Abstract

For the first time in the south of the Russian Far East in the Late Pleistocene cave deposits, fragments of the giant flying squirrel of the genus Petaurista were discovered. Petaurista tetyukhensis n. sp. is described based on a fragment of the upper jaw with two teeth and five isolated teeth from two cave locations. The main differences between the new species and living forms as well as other fossil species of the genus Petaurista are the absence of vertical groove on the lingual wall between the protocone and hypocone on M2, the absence of the anterior cross loph on the upper P4-M3, and the absence of mesoconids on lower, as a result of which the hypoflexid is not w-shaped. It is suggested that the Sikhote-Alin refugium allowed individual species to survive there during long unfavourable period of time and was the centre of speciation.

Keywords: New species, Giant flying squirrels, Late Pleistocene, Refugium, Sikhote-Alin

Systematic palaeontology 

Class Mammalia Linnaeus, 1758 

Order Rodentia Bowdich, 1821 

Family Sciuridae Hemprich, 1820 

Subfamily Sciurinae Fischer de Waldheim, 1817 

Tribe Pteromyini Brandt, 1855 

Genus Petaurista Link, 1795 

Occlusal view of RPRV–TetC–01, the fragmentary maxillae of Petaurista tetyukhensis n. sp., holotype.

Upper and lower cheek teeth of Petaurista tetyukhensis n. sp. 

Petaurista tetyukhensis n. sp. 

 Etymology: The species is named after type locality. The old name of Dalnegorsk Town (Tetyukhe) is used.

   

 Mikhail P. Tiunov and Dmitryi O. Gimranov. 2019. The First Fossil Petaurista (Mammalia: Sciuridae) from the Russian Far East and Its Paleogeographic Significance. Palaeoworld. In Press.  DOI: 10.1016/j.palwor.2019.05.007

New species of a giant flying squirrel discovered in the Far East of Russia

 siberiantimes.com/science/others/news/new-species-of-a-giant-flying-squirrel-discovered-in-the-far-east-of-russia/

[Mammalogy • 2019] Biswamoyopterus gaoligongensis • Discovery and Description of A Mysterious Asian Flying Squirrel (Rodentia, Sciuridae, Biswamoyopterus) from Mount Gaoligong, southwest China

Biswamoyopterus gaoligongensis 

Li, Li, Jackson, Li, Jiang, Zhao, Song & Jiang, 2019

 DOI: 10.3897/zookeys.864.33678

Abstract

The flying squirrels of the tribe Pteromyini (Family Sciuridae) currently include 15 genera of which the genus Biswamoyopterus comprises two recognized species, B. biswasi Saha, 1981 and B. laoensis Sanamxay et al., 2013. These two species were each described from only one specimen that are separated from each other by 1,250 kilometres in southern Asia, where they occur in northeast India and central Lao PDR respectively. In 2017 and 2018, two specimens of Biswamoyopterus were discovered from Mount Gaoligong, west Yunnan province, southwest China (between the type locality of the two recognized species). This study aimed to evaluate the taxonomic status of these two newly acquired specimens of Biswamoyopterus by comparing their morphology with the two described species of the genus. The results of this study showed that the specimens from Yunnan province (China) differed from both B. laoensis and B. biswasi in both pelage colour and craniology, and should be recognised as a distinct species, Biswamoyopterus gaoligongensis sp. nov., which is formally described here. This study contributes to the understanding of the flying squirrels of southern Asia and identifies an additional species that appears to be endemic to southwest China; however, more research is required to provide details of its ecology, distribution, and conservation status.

Keywords: Biodiversity, conservation, mammal, Pteromyini, systematics, taxonomy, threatened, wildlife, Yunnan

Figure 1. Known localities of three species of Biswamoyopterus.

     

Figure 4. Skins of the three known Biswamoyopterus species
A, B (ZSI 20705, holotype) Biswamoyopterus biswasi C, D (KIZ 034924, holotype)  Biswamoyopterus gaoligongensis sp. nov.
E, F (NUoL FES.MM.12.163, holotype) Biswamoyopterus laoensis. The images E, F were derived from Sanamxay et al. (2013).

 Figure 5. Skulls, left maxillary (above) and left mandibular (below) tooth rows of the three known Biswamoyopterus species.
A (ZSI 20705, holotype) Biswamoyopterus biswasi B (KIZ 034924, holotype)  Biswamoyopterus gaoligongensis sp. nov. C (NUoL FES.MM.12.163, holotype) Biswamoyopterus laoensis. The images of C were derived from Sanamxay et al. (2013).

Taxonomy

Class Mammalia Linnaeus, 1758
Order Rodentia Bowdich, 1821

Family Sciuridae Fischer, 1817
Subfamily Sciurinae Fischer, 1817
Tribe Pteromyini Brandt, 1855

Genus Biswamoyopterus Saha, 1981

Biswamoyopterus gaoligongensis sp. nov. 

Common name: Mount Gaoligong Flying Squirrel. 

Chinese common name "高黎贡比氏鼯鼠".

Etymology: The specific name is derived from Mount Gaoligong, the type locality of the new species and –ensis, Latin for belonging to.

Diagnosis: Biswamoyopterus gaoligongensis sp. nov. can be distinguished from the other two described species of Biswamoyopterus by the following combination of traits: 1) The ear tufts at the base of the posterior margins of ears are bicolored, basally white and terminal black. The scrotum is dark brown which strongly contrasts with the yellowish-white abdominal pelage. 2) The muzzle is very short, and the zygomatic arch is distinctly expanding outward, making the outline of the skull short and wide. The outer margin of the nasal bone, the orbital margin of the frontal bone, and the post-orbital margin of the frontal bone are almost parallel to the midline of skull on the dorsal view. The central point of the posterior margin of the palatal bones lies in front of the posterior margin of M3. 3) M1 and M2 are sub-square in outline, and as large as P4. The hypoconid of P4-M2 are very developed, strongly pointed towards posterior buccal side.

Figure 6. Ear tufts of the three Biswamoyopterus species, the red arrow indicates the anterior tufts, and the yellow arrow indicates the posterior tufts
 A (ZSI 20705, holotype) Biswamoyopterus biswasi B (KIZ 034924, holotype)  Biswamoyopterus gaoligongensis sp. nov. C (NUoL FES.MM.12.163, holotype) Biswamoyopterus laoensis. The image C was derived from Sanamxay et al. (2013).

Distribution: Apart from the locality of the holotype, there are two more localities in Yunnan, China, where the Biswamoyopterus gaoligongensis sp. nov. was photographed. These include Linjiapu, 10 km west of the type locality; and Banchang, 9 km south of the type locality (Fig. 1). Although these three localities cover the east and west slopes of Mount Gaoligong (the watershed of the Irrawaddy River and the Nu River [Salween River]), they are all restricted in a small area of southern Mount Gaoligong.

Natural history: Little is known about the natural history of Biswamoyopterus gaoligongensis sp. nov. The holotype was collected from evergreen broad-leaved forest at an altitude of 2,000 meters above sea level. A set of photos taken in Linjiapu showed a Biswamoyopterus gaoligongensis sp. nov. resting on the branches of Daphniphyllum sp. Petaurista yunanensis, P. elegans, and Hylopetes alboniger were also collected in the same habitat where the holotype was collected.

 Quan Li, Xue-You Li, Stephen M. Jackson, Fei Li, Ming Jiang, Wei Zhao, Wen-Yu Song and Xue-Long Jiang. 2019. Discovery and Description of A Mysterious Asian Flying Squirrel (Rodentia, Sciuridae, Biswamoyopterus) from Mount Gaoligong, southwest China. ZooKeys. 864: 147-160.  DOI: 10.3897/zookeys.864.33678

New species of flying squirrel from Southwest China added to the rarest and 'most wanted' |blog.pensoft.net/2019/07/18/new-species-of-flying-squirrel-from-southwest-china-added-to-the-rarest-and-most-wanted

[PaleoMammalogy • 2018] Miopetaurista neogrivensis • Oldest Skeleton of A Fossil Flying Squirrel Casts New Light on the Phylogeny of the Group

Miopetaurista neogrivensis Mein 1970

in Casanovas-Vilar, Garcia-Porta, Fortuny, et al., 2018. 

DOI:  10.7554/eLife.39270.001

Abstract

Flying squirrels are the only group of gliding mammals with a remarkable diversity and wide geographical range. However, their evolutionary story is not well known. Thus far, identification of extinct flying squirrels has been exclusively based on dental features, which, contrary to certain postcranial characters, are not unique to them. Therefore, fossils attributed to this clade may indeed belong to other squirrel groups. Here we report the oldest fossil skeleton of a flying squirrel (11.6 Ma) that displays the gliding-related diagnostic features shared by extant forms and allows for a recalibration of the divergence time between tree and flying squirrels. Our phylogenetic analyses combining morphological and molecular data generally support older dates than previous molecular estimates (~23 Ma), being congruent with the inclusion of some of the earliest fossils (~36 Ma) into this clade. They also show that flying squirrels experienced little morphological change for almost 12 million years.

Fig 1: The fossil flying squirrel Miopetaurista neogrivensis.
 (a) Reconstruction of the skeleton based in the partial skeleton IPS56468 from Abocador de Can Mata. Missing elements are based on extant giant flying squirrel Petaurista petaurista and are colored in blue.
(b) Life appearance of Miopetaurista neogrivensis showing the animal ready to land on a tree branch. Coat pattern and color are based in extant Petaurista species, the sister taxon of Miopetaurista.  Scale bar is 4 cm.

Fig 3: Mandible and cheek teeth of Miopetaurista neogrivensis.
 (a to c) Partial left hemimandible (IPS56468j) in lateral, medial and dorsal views. (d to e) Partial right hemimandible (IPS56468i) in lateral and medial views. A caudal vertebra and a bone fragment are attached to the lateral side of the mandibular ramus. Both hemimandibles were associated to the partial skeleton IPS56468 from ACM/C5-D1. (f to g) Partial hemimandible (IPS87560) from ACM/C8-B sector in lateral and medial views. (h) Left upper cheek teeth series (P3–M3) of IPS56468h (Figure 6—Figure supplement 1 ). (i) Left lower cheek teeth series (p4–m3) of IPS56468j. Cheek teeth measurements are given in Supplementary file 4 whereas mandibular measurements are given in Supplementary file 6. For a detailed description and comparisons of cheek teeth and mandible morphology see Appendix 3.1 and 3.2. an, angular process; ar, articular process; co, coronoid process. Scale bar is 1 cm in figs. a to g; 2 mm in (h to i).

Fig 7: Flying squirrel phylogeny and node dating estimates based on a Bayesian total evidence analysis including Miopetaurista neogrivensis.

Fig 8: Fossil record of ‘flying squirrels’ and paleoclimatic data. Temporal ranges of purported flying squirrel genera in Europe, Asia and North America. The 95% highest posterior density (HPD) intervals for flying squirrel divergence as derived from total evidence and node dating analyses are indicated in orange shading (see Figure 7 and Figure 7—figure supplement 1 ). Darker shading indicates the time interval where both independently calculated estimates overlap, thus defining the most likely time interval for flying squirrel divergence. Global paleoclimatic data are taken from Zachos et al., 2001.

Conclusions: 

Miopetaurista neogrivensis is the oldest unquestionable flying squirrel and dates back to the middle/late Miocene boundary (11.6 Ma). Its diagnostic wrist anatomy indicates that the two subtribes of flying squirrels had already diverged at that time. Moreover, this new fossil allows for a recalibration of flying squirrel time of origin and diversification, generally providing somewhat older estimates than previous molecular analyses. These differ according to the phylogenetic method used, total evidence analysis estimates an interval of 36.6 – 24.9 Ma while node dating results in a younger estimate of 30.6 – 17.4 Ma. Therefore, we cannot rule out that at least some of the oldest (ca. 36 Ma) fossils tentatively identified as flying squirrels may indeed belong to this group. However, the estimates of both independent phylogenetic approaches overlap for the late Oligocene (31 – 25 Ma), which should be considered the most likely interval for flying squirrel divergence. The two flying squirrel subtribes are found to have diverged during the early Miocene (22 – 18 Ma) while most extant genera would do so during the Miocene, although they are not recorded until the Pleistocene. Miopetaurista neogrivensis is estimated to have diverged from Petaurista spp., its sister taxon, between 18.8 – 12.4 Ma, the oldest boundary overlapping with the earliest record of the genus Miopetaurista (18 – 17 Ma). Perhaps not surprisingly, the skeletons of both genera show little differences. Sciurids are often regarded as a morphologically conservative group and flying squirrels are no exception having experienced few morphological changes for almost 12 million years.

Isaac Casanovas-Vilar, Joan Garcia-Porta, Josep Fortuny, Óscar Sanisidro, Jérôme Prieto, Marina Querejeta, Sergio Llácer, Josep M Robles, Federico Bernardini, and David M Alba. 2018. Oldest Skeleton of A Fossil Flying Squirrel Casts New Light on the Phylogeny of the Group.  eLife. 7; e39270 DOI:  10.7554/eLife.39270.001

Oldest fossil of a flying squirrel sheds new light on its evolutionary tree
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[Mammalogy • 2018] Systematics, Distribution and Ecological Analysis of Rodents in Jordan

Acomys russatus lewisi  Atallah, 1967

in Amr, Abu Baker, Qumsiyeh & Eid, 2018.

  DOI:  10.11646/zootaxa.4397.1.1 

Abstract

Distributional and ecological data were given to all rodents of Jordan. The rodent fauna of Jordan consists of 28 species with 20 genera in eight families (Cricetidae, Dipodidae, Gliridae, Hystricidae, Muridae, Myocastoridae, Sciuridae,and Spalacidae), including four introduced species.Keys for families and species were provided, along with diagnosis for each species and cranial illustrations for most species. Habitat preference and zoogeographic affinities of rodents in Jordan were analyzed, as well as their status and conservation.Threat categories and causes of threats on the rodents of Jordan were also analyzed.

        The distribution of rodents in Jordan represents a reflection of their global distribution ranges and habitat preferences. Species associated with the temperate forest of northern Jordan includes Sciurus anomalus and two wood mice, Apodemus mystacinus and A. flavicollis, while non-forested areas are represented by Nannospalax ehrenbergi and Microtus guentheri. Strict sand dwellers include Gerbillus cheesmani and G. gerbillus. Petrophiles associated with sandstone or black lava deserts are exemplified by Acomys russatus, A. r. lewsi, H. indica and S. calurus. Others including: Jaculus jaculus, G. nanus, G. henleyi, Meriones crassus, and M. libycus are all desert-adapted species with wider ranges of distribution where scarce vegetation, wadibeds, and marabs with clay, loess, or gravel surfaces provide foraging grounds and shelter. A single species, Gerbillus dasyurus, exhibits a wide range of distribution over diverse habitat types.

        The rodent fauna of Jordan consists of assemblages of different zoogeographical affinities. Nine, three, and seven were restricted or had most of its range within the Mediterranean, Irano-Turanian, and Saharo Arabian, respectively. Sciurus anomalus, Apodemus sp., Nannospalax ehrenbergi, and Microtus guentheri reached their most southern range of distribution in the Mediterranean regions of Jordan. The distribution of Gerbillus cheesmani extends from Asian deserts in India westwards into the Arabian Peninsula crossing Jordan as its most western range of distribution. Typical rodents of Saharo-Arabian affinities are represented by desert jerboas, gerbils, and jirds. North African species such as G. andersoni, G. gerbillus reached their most eastern distribution in southern Jordan. Both G. henleyi and G. nanus are widely-distributed species across North Africa reaching as far as India to the east, representing most northern outpost for these two species. Sekeetamys calurus is a nearly endemic to the Eastern Mediterranean region within southern Jordan and Sinai. Relicts are represented by Eliomys melanurus and Acomys russatus lewisi.

        Several threats affecting the rodent biodiversity in Jordan were identified including habitat loss and degradation, human disturbance and related activity, legislative and public awareness. The global conservation status of the rodents of Jordan according to the IUCN Red List include 22 species as least concern, one as near threatened (Allactaga euphratica), and one as data deficient (Nannospalax ehrenbergi). According to the regional assessment, one species is critically endangered, three species are considered endangered, one vulnerable.

Keywords: Mammalia, biodiversity, habitat preference, Jordan, rodents, zoogeography

Acomys russatus lewisi Atallah, 1967 

Zuhair S. Amr, Mohammad A. Abu Baker, Mazin Qumsiyeh and  Ehab Eid. 2018.  Systematics, Distribution and Ecological Analysis of Rodents in Jordan. Zootaxa. 4397(1);  1-94.   DOI:  10.11646/zootaxa.4397.1.1

[Mammalogy • 2017] Glaucomys oregonensis • Genetic Data Reveal A Cryptic Species of New World Flying Squirrel

Glaucomys oregonensis  (Bachman, 1839)

DOI: 10.1093/jmammal/gyx055  

Photograph by N. Kerhoulas. NationalGeographic.com

Abstract

The genus Glaucomys (New World flying squirrels) is currently considered to be comprised of 2 species, the northern flying squirrel (G. sabrinus) and the southern flying squirrel (G. volans). We synthesize new information from mitochondrial DNA (mtDNA) control region sequences and microsatellite data to demonstrate that the genus consists of 3, rather than 2 species, and that Glaucomys sabrinus, as currently recognized, is actually composed of 2 separate, apparently non-hybridizing species. Control region mtDNA data from 185 individuals across North America revealed 2 distinct clades embedded within G. sabrinus: a widespread “Continental” lineage and a more geographically restricted “Pacific Coastal” lineage. The geographic distributions of these 2 lineages are largely mutually exclusive, with sympatry observed at only 3 sites in the Pacific Northwest. Analysis of 8 microsatellite loci showed no evidence of hybridization between the 2 lineages of G. sabrinus in the region of sympatry. This lack of gene flow is noteworthy given that populations of the Continental lineage of G. sabrinus have been shown to hybridize with G. volans in southeastern Canada. Finally, phylogenetic analyses and estimates of divergence times show that G. volans and Continental G. sabrinus are actually sister taxa that diverged from one another more recently than either did from Pacific Coastal G. sabrinus. We propose that these observations provide strong evidence for a third, previously unrecognized species of North American flying squirrel, whose geographic range extends along the Pacific Coast from southern British Columbia to southern California. Glaucomys oregonensis (Bachman, 1839), whose type locality is in Oregon, is the senior available name for this taxon. We propose that this newly recognized species be given the common name “Humboldt’s flying squirrel.”

Keywords: cryptic speciation, Glaucomys oregonensis, Glaucomys sabrinus, Glaucomys volans, Humboldt’s flying squirrel, microsatellites, phylogeography, Rodentia, Sciuridae

Brian S. Arbogast, Katelyn I. Schumacher, Nicholas J. Kerhoulas, Allison L. Bidlack, Joseph A. Cook and G. J. Kenagy. 2017. Genetic Data Reveal A Cryptic Species of New World Flying Squirrel: Glaucomys oregonensis.  Journal of Mammalogy. DOI: 10.1093/jmammal/gyx055 

Meet This Newly Discovered Flying Squirrel on.natgeo.com/2qxAX9s via @NatGeo

news.NationalGeographic.com/2017/05/flying-squirrel-new-species-north-america/