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Endo H, Nguyen TS, Nguyen DD, Sasaki M, Kimura J, Oshida T, Yago M, Ly NT, Nguyen TT, Motokawa M. Zoogeographical barriers causing discontinuous osteometrical variations in the northern treeshrew skulls. J Vet Med Sci 2021; 83:1534-1544. [PMID: 34380913 PMCID: PMC8569870 DOI: 10.1292/jvms.21-0322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Morphological variation of the skull was examined in the northern treeshrew
(Tupaia belangeri) from various localities across Southeast Asia.
Through a multivariate analysis, the treeshrews from South Vietnam exhibited distinct
morphological characteristics compared to other populations from Thailand and Laos, and
Malaysia. The plots of the specimens of North Vietnam are not randomly mixed with Thailand
plots segregation in the scatteregrams of canonical discriminant analysis. Since the
skulls of the population from North Vietnam were morphologically similar to those form
central Laos and northern and northeastern Thailand, the zoogeographical barrier effect of
Mekong River was not clearly confirmed. The population of the Kanchanaburi in western
Thailand is clearly smaller in size compared to the other populations. The southern border
of the distribution of this species is determined by the Isthmus of Kra or Kangar-Pattani
Line. In the northern treeshrew, which is distributed from southern China to Bangladesh
and southern Thailand, we have detected osteometrical geographical variation driven by
geography. These results indicate that the skull morphology in the Tupaia
glis-belangeri complex distinctively differs in South Vietnam, western
Thailand, and southern Thailand. The zoogeographical barrier and factor separating these
districts are expected to clarify in the future.
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Affiliation(s)
- Hideki Endo
- The University Museum, The University of Tokyo
| | - Truong Son Nguyen
- Department of Vertebrate Zoology, Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology.,Graduate University of Science and Technology, Vietnam Academy of Science and Technology
| | - Dinh Duy Nguyen
- Department of Vertebrate Zoology, Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology
| | - Motoki Sasaki
- Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine
| | - Junpei Kimura
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Seoul National University
| | - Tatsuo Oshida
- Laboratory of Wildlife Ecology, Obihiro University of Agriculture and Veterinary Medicine
| | - Masaya Yago
- The University Museum, The University of Tokyo
| | - Ngoc Tu Ly
- Department of Vertebrate Zoology, Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology
| | - Thi Tham Nguyen
- Faculty of Environmental Sciences, University of Science, Vietnam National University.,Central Institute for Natural Resources and Environmental Studies, Vietnam National University
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Woodman N, Miller-Murthy A, Olson LE, Sargis EJ. Coming of age: morphometric variation in the hand skeletons of juvenile and adult Lesser Treeshrews (Scandentia: Tupaiidae: Tupaia minor Günther, 1876). J Mammal 2020. [DOI: 10.1093/jmammal/gyaa056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Morphometric analyses of the manus skeleton have proven useful in understanding species limits and morphological divergence among tupaiid treeshrews (Scandentia: Tupaiidae). Specimens in these studies are typically limited to mature individuals with fully erupted permanent dentition, which eliminates potentially confounding variation attributable to age, but also can exclude rare taxa and small island populations that are poorly represented in systematic collections. To determine the real limits associated with including immature animals in such studies, we used multivariate analyses to study sexual and age variation of the manus skeleton in two allopatric populations of the Lesser Treeshrew (Tupaia minor Günther, 1876) from the Malay Peninsula and from Borneo that we treated as separate samples. Individuals were aged using dental eruption of the permanent dentition. We also recorded the degree of epiphyseal fusion of the bones of the manus based on x-rays of study skins. We then tested our ability to distinguish the two populations using a series of discriminant function analyses of hand measurements from samples that included varying proportions of immature individuals and adults. We found no evidence of sexual dimorphism in hand proportions, permitting us to combine females and males in our samples. Epiphyseal fusion of the metacarpals and phalanges typically occurs by the time the third molars have completely erupted, and fusion of the distal epiphyses of the radius and ulna typically occurs by the time the permanent fourth premolars are in place. There is occasional asynchrony between dental age and epiphyseal fusion. In both populations, the hands of most infants and subadults provide morphometric values within the range of variation of adults, although they are typically distributed in the lower part of the adult range and have the potential to bias the sample toward lower mean size. The inclusion of infants and subadults when attempting to discriminate between two taxa generally results in lower rates of correct classifications, although the rates increase as the sample of immature individuals is limited to older subadults. As a general rule, we recommend that specimens of infants and subadults continue to be excluded from analyses when exploring taxonomic boundaries among treeshrews. In cases of extremely small sample sizes of adults, however, older subadults—in which the permanent third premolars are erupting or in place—can be used with appropriate caution.
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Affiliation(s)
- Neal Woodman
- U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, MD, USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Ananth Miller-Murthy
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History, New Haven, CT, USA
| | - Link E Olson
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Eric J Sargis
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History, New Haven, CT, USA
- Department of Anthropology, Yale University, New Haven, CT, USA
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Sargis EJ, Woodman N, Morningstar NC, Bell TN, Olson LE. Skeletal variation and taxonomic boundaries among mainland and island populations of the common treeshrew (Mammalia: Scandentia: Tupaiidae). Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eric J. Sargis
- Department of Anthropology; Yale University; P.O. Box 208277 New Haven CT 06520 USA
- Department of Ecology and Evolutionary Biology; Yale University; P.O. Box 208106 New Haven CT 06520 USA
- Division of Vertebrate Zoology; Yale Peabody Museum of Natural History; New Haven CT 06520 USA
| | - Neal Woodman
- United States Geological Survey; Patuxent Wildlife Research Center; National Museum of Natural History; Smithsonian Institution; Washington DC 20013 USA
| | | | - Tiffany N. Bell
- Department of Ecology and Evolutionary Biology; Yale University; P.O. Box 208106 New Haven CT 06520 USA
| | - Link E. Olson
- University of Alaska Museum; University of Alaska Fairbanks; Fairbanks AK 99775 USA
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Endo H, Tsuchiya K. A new species of Ryukyu spiny rat, Tokudaia (Muridae: Rodentia), from Tokunoshima Island, Kagoshima Prefecture, Japan. MAMMAL STUDY 2006. [DOI: 10.3106/1348-6160(2006)31[47:ansors]2.0.co;2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Endo H, Hikida T, Motokawa M, Chou LM, Fukuta K, Stafford BJ. Morphological adaptation of the skull for various behaviors in the tree shrews. J Vet Med Sci 2003; 65:873-9. [PMID: 12951419 DOI: 10.1292/jvms.65.873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Skull size and shape were examined among 14 species of the tree shrews (Tupaia montana, T. picta, T. splendidula, T. mulleri, T. longipes, T. glis, T. javanica, T. minor, T. gracilis, T. dorsalis, T. tana, Dendrogale melanura, D. murina, and Ptilocercus lowii). The bones of face were rostro-caudally longer in T. tana and T. dorsalis, contrasting with T. minor and T. gracilis, D. melanura, D. murina and P. lowii which have smaller facial length ratios. The arbo-terrestrial species (T. longipes and T. glis) were similar to terrestrial species in length ratios of bones of face unlike the other arbo-terrestrial species (T. montana, T. picta, T. splendidula, and T. mulleri). We propose that T. longipes and T. glis have adapted to foraging for termites and ants as have T. tana and T. dorsalis. Additionally small body size in T. javanica may be the result of being isolated in Java. We separated the species into 5 groups from the measurment values of skulls: 1) Terrestrial species; T. tana and T. dorsalis, 2) Arboreal species; T. minor and T. gracilis, 3) Arbo-terrestrial species group 1: T. montana, T. splendidula, T. picta and T. mulleri, and T. javanica, 4) Arbo-terrestrial species group 2: T. glis and T. longipes, 5) Arboreal species of Dendrogale and Ptilocercus. Principal component analysis separated species into 8 clusters as follows: 1) T. tana, 2) T. dorsalis, 3) T. montana, T. splendidula, T. picta and T. mulleri, 4) T. glis and T. longipes, 5) T. javanica, 6) T. minor and T. gracilis, 7) D. melanura and D. murina, and 8) P. lowii. We suggest that these clusters correspond to behavioral strategies and peculiarities observed in foraging, feeding and locomotion in each species.
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Affiliation(s)
- Hideki Endo
- Department of Zoology, National Science Museum, Tokyo, Japan
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Endo H, Hayashi Y, Rerkamnuaychoke W, Nadee N, Nabhitabhata J, Kawamoto Y, Hirai H, Kimura J, Nishida T, Yamada J. Sympatric distribution of the two morphological types of the common tree shrew in Hat-Yai districts (South Thailand). J Vet Med Sci 2000; 62:759-61. [PMID: 10945296 DOI: 10.1292/jvms.62.759] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The two color types (grayish northern and reddish southern types) of the common tree shrew (Tupaia glis and Tupaia belangeri) were co-distributed in Hat-Yai region (South Thailand). Although the Isthmus of Kra in South Thailand has been considered as distribution barrier of the two types, the sympatric distribution of both types was confirmed in southern side of the Isthmus. In the principal component analysis, the skull measurement character from Hat-Yai region could also be separated into the northern and southern groups according to the skin color identification of corresponding individuals. We could generally distinguish the common tree shrew into two types by skull morphology as well as external skin color.
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Affiliation(s)
- H Endo
- Department of Zoology, National Science Museum, Tokyo, Japan
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Endo H, Nishiumi I, Hayash Y, Rerkamnuaychoke W, Kawamoto Y, Hirai H, Kimura J, Suyanto A, Nabhitabhata J, Yamada J. Osteometrical skull character in the four species of tree shrew. J Vet Med Sci 2000; 62:517-20. [PMID: 10852401 DOI: 10.1292/jvms.62.517] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The skull size and shape were osteometrically examined in the four species of the tree shrews (Tupaia tana, T. javanica, T. minor and T. dorsalis). We suggest that the skull characters were affected by the species specific behavior and terrestrial, arbo-terrestrial and arboreal life, among the genus Tupaia. The neurocranium was laterally narrower in the braincase area, and the splanchnocranium was longer only on dorsal side in T. tana, and these characters were opposite to T. minor. The principal component analysis confirmed the obviously separated clusters among T. tana, T. javanica and T. minor, affected by the adaptation for each behavior. T. dorsalis was considered as terrestrial species from the results of proportion analysis and the principal component analysis.
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Affiliation(s)
- H Endo
- Department of Zoology, National Science Museum, Tokyo, Japan
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Endo H, Nishiumi I, Hayashi Y, Rashdi AB, Nadee N, Nabhitabhata J, Kawamoto Y, Kimura J, Nishida T, Yamada J. Multivariate analysis in skull osteometry of the common tree shrew from both sides of the Isthmus of Kra in Southern Thailand. J Vet Med Sci 2000; 62:375-8. [PMID: 10823723 DOI: 10.1292/jvms.62.375] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Isthmus of Kra in Southern Thailand consists of a lowland of about 70 km in length. It has been suggested that the Isthmus may sink beneath the sea surface according to the change of level of the sea, and may function as a zoogeographical barrier in land mammals in this region. So, the geographical variation was osteometrically examined in skull of the common tree shrew (Tupaia glis) from the both sides of Isthmus of Kra. The osteometrical examination demonstrated that the skull is larger in southern population than in northern one. In the charts of the principal component analysis, however, the morphological separation between two populations can not be obviously seen in female. While, the results of the discriminant analysis indicated the morphological separation between the two populations. These findings suggest that the zoogeographical barrier of Isthmus of Kra may have influence on the osteometrical variation in the common tree shrew, when the Isthmus was covered with sea.
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Affiliation(s)
- H Endo
- Department of Zoology, National Science Museum, Tokyo, Japan
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