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Juman MM, Woodman N, Miller-Murthy A, Olson LE, Sargis EJ. Taxonomic boundaries in Lesser Treeshrews (Scandentia, Tupaiidae: Tupaia minor ). J Mammal 2022. [DOI: 10.1093/jmammal/gyac080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
The Lesser Treeshrew, Tupaia minor Günther, 1876, is a small mammal from Southeast Asia with four currently recognized subspecies: T. m. minor from Borneo; T. m. malaccana from the Malay Peninsula; T. m. humeralis from Sumatra; and T. m. sincepis from Singkep Island and Lingga Island. A fifth subspecies, T. m. caedis, was previously synonymized with T. m. minor; it was thought to occur in northern Borneo and on the nearby islands of Banggi and Balambangan. These subspecies were originally differentiated based on pelage color, a plastic feature that has proven to be an unreliable indicator of taxonomic boundaries in treeshrews and other mammals. To explore infraspecific variation among T. minor populations across the Malay Peninsula, Borneo, Sumatra, and smaller islands, we conducted multivariate analyses of morphometric data collected from the hands and skulls of museum specimens. Principal component and discriminant function analyses reveal limited differentiation in manus and skull proportions among populations of T. minor from different islands. We find no morphometric support for the recognition of the four allopatric subspecies and no support for the recognition of T. m. caedis as a separate subspecies on Borneo.
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Affiliation(s)
- Maya M Juman
- Department of Ecology and Evolutionary Biology, Yale University , New Haven, Connecticut 06520 , USA
| | - Neal Woodman
- U.S. Geological Survey, Eastern Ecological Science Center , Laurel, Maryland 20708 , USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution , Washington, District of Columbia 20013 , USA
| | - Ananth Miller-Murthy
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History , New Haven, Connecticut 06520 , USA
| | - Link E Olson
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution , Washington, District of Columbia 20013 , USA
- Department of Mammalogy, University of Alaska Museum, University of Alaska Fairbanks , Fairbanks, Alaska 99775 , USA
| | - Eric J Sargis
- Department of Ecology and Evolutionary Biology, Yale University , New Haven, Connecticut 06520 , USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution , Washington, District of Columbia 20013 , USA
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History , New Haven, Connecticut 06520 , USA
- Department of Anthropology, Yale University , New Haven, Connecticut 06520 , USA
- Yale Institute for Biospheric Studies , New Haven, Connecticut 06520 , USA
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Skeletal Variation and Taxonomic Boundaries in the Pen-tailed Treeshrew (Scandentia: Ptilocercidae; Ptilocercus lowii Gray, 1848). J MAMM EVOL 2021. [DOI: 10.1007/s10914-021-09556-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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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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Juman MM, Woodman N, Olson LE, Sargis EJ. Ecogeographic variation and taxonomic boundaries in Large Treeshrews (Scandentia, Tupaiidae: Tupaia tana Raffles, 1821) from Southeast Asia. J Mammal 2021. [DOI: 10.1093/jmammal/gyab059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
The Large Treeshrew, Tupaia tana Raffles, 1821, is a small mammal (~205 g) from Southeast Asia with a complicated taxonomic history. Currently, 15 subspecies are recognized from Borneo, Sumatra, and smaller islands, and many were originally differentiated based on minor pelage differences and small sample sizes. We explored intraspecific variation in T. tana using quantitative osteological data obtained from the hands and skulls of museum specimens. Multivariate analyses reveal extensive overlap among T. tana populations in morphospace, indicating that the majority of currently recognized subspecies are not morphometrically distinct. In contrast, the separation between Bornean and Sumatran populations of T. tana is sufficient to recognize them as different subspecies. Comparisons of Bornean specimens to those on small, offshore islands reveal that the latter average smaller body size. This pattern is inconsistent with Foster’s island rule, which predicts that island populations of small mammals (< 5 kg) will average larger body size relative to mainland forms. A similar lack of support for ecogeographic rules has been noted in T. glis (Diard, 1820), suggesting that these “rules” are poor predictors of geographic variation in treeshrews.
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Affiliation(s)
- Maya M Juman
- Department of Ecology and Evolutionary Biology, Yale University , New Haven, CT , USA
| | - Neal Woodman
- U.S. Geological Survey, Eastern Ecological Science Center , Laurel, MD , USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution , Washington, DC , USA
| | - Link E Olson
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution , Washington, DC , USA
- Department of Mammalogy, University of Alaska Museum, University of Alaska Fairbanks , Fairbanks, AK , USA
| | - Eric J Sargis
- Department of Ecology and Evolutionary Biology, Yale University , New Haven, CT , USA
- 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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Woodman N, Miller-Murthy A, Olson LE, Sargis EJ. The limitations of external measurements for aging small mammals: the cautionary example of the Lesser Treeshrew (Scandentia: Tupaiidae: Tupaia minor Günther, 1876). J Mammal 2021. [DOI: 10.1093/jmammal/gyab055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Age is a basic demographic characteristic vital to studies of mammalian social organization, population dynamics, and behavior. To eliminate potentially confounding ontogenetic variation, morphological comparisons among populations of mammals typically are limited to mature individuals (i.e., those assumed to have ceased most somatic growth). In our morphometric studies of treeshrews (Scandentia), adult individuals are defined by the presence of fully erupted permanent dentition, a common criterion in specimen-based mammalogy. In a number of cases, however, we have had poorly sampled populations of interest in which there were potentially useful specimens that could not be included in samples because they lacked associated skulls. Such specimens typically are associated with external body and weight measurements recorded by the original collectors, and we sought to determine whether these data could be used successfully as a proxy for age or at least to establish maturity. We analyzed four traditional external dimensions (head-and-body length, tail length, hind foot length, and ear length) and weight associated with 103 specimens from two allopatric populations of the Lesser Treeshrew (Tupaia minor Günther, 1876) from Peninsular Malaysia and from Borneo, which we treated as separate samples (populations). Individuals were assigned to one of eight age categories based on dental eruption stage, and measurements were compared among groups. In general, mean sizes of infants and subadults were smaller than those of adults, but the majority of subadults fell within the range of variation of adults. The large overlap among infants, subadults, and adults in external measurements and weight indicates that such measures are poor proxies for age in this species, probably for treeshrews in general, and possibly for other small mammals. This has significant implications for any investigation wherein relative age of individuals in a given population is an important consideration.
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Affiliation(s)
- Neal Woodman
- U.S. Geological Survey, Eastern Ecological Science 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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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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Weiss KR, Chester SGB, Olson LE, Sargis EJ. Postcranial Skeletal Variation in Pencil-Tailed Tree Mice (Rodentia: Muridae: Chiropodomys): Functional, Ecogeographic, and Taxonomic Implications. BULLETIN OF THE PEABODY MUSEUM OF NATURAL HISTORY 2020. [DOI: 10.3374/014.061.0102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Stephen G. B. Chester
- Department of Anthropology and Archaeology, Brooklyn College, City University of New York, Brooklyn, NY 11210 USA; Department of Anthropology, The Graduate Center, City University of New York, New York, NY, 10016 USA; and New York Consortium in Evolu
| | - Link E. Olson
- Department of Mammalogy, University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK 99775 USA
| | - Eric J. Sargis
- Division of Vertebrate Paleontology, Peabody Museum of Natural History, Yale University, New Haven, CT 06520 USA
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Woodman N, Wilken AT. Comparative functional skeletal morphology among three genera of shrews: implications for the evolution of locomotor behavior in the Soricinae (Eulipotyphla: Soricidae). J Mammal 2019. [DOI: 10.1093/jmammal/gyz098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
The clade comprising the soricid tribes Blarinellini (Blarinella) and Blarinini (Blarina and Cryptotis) is notable within the Soricidae (Eulipotyphla) for the large proportion of reportedly semifossorial species. To better define locomotor modes among species in these two tribes, we quantified purported locomotor adaptations by calculating 23 functional indices from postcranial measurements obtained from museum specimens of Blarina and Blarinella and published measurements for 16 species of Cryptotis. We then analyzed relative ambulatory–fossorial function of each species using principal component analyses and mean percentile rank (MPR) analysis of the indices. Species within the Blarinellini–Blarinini clade exhibit a graded series of morphologies with four primary functional groupings that we classified as “ambulatory,” “intermediate,” “semifossorial,” and “fossorial.” To obtain a preliminary overview of evolution of locomotor modes in this group, we mapped MPRs on a composite phylogeny and examined the resulting patterns. That analysis revealed that the most recent common ancestor of the Blarinellini–Blarinini clade most likely had an intermediate or semifossorial locomotor morphology. Individual subclades subsequently evolved either more ambulatory or more fossorial morphologies. Hence, evolution of locomotor traits within this clade is complex. Multiple shifts in locomotor mode likely occurred, and no single directional tendency is apparent either among the major modes or in levels of complexity.
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Affiliation(s)
- Neal Woodman
- USGS Patuxent Wildlife Research Center, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Alec T Wilken
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
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Selig KR, Sargis EJ, Silcox MT. The frugivorous insectivores? Functional morphological analysis of molar topography for inferring diet in extant treeshrews (Scandentia). J Mammal 2019. [DOI: 10.1093/jmammal/gyz151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AbstractThe ecology, and particularly the diet, of treeshrews (order Scandentia) is poorly understood compared to that of their close relatives, the primates. This stems partially from treeshrews having fast food transit times through the gut, meaning fecal and stomach samples only represent a small portion of the foodstuffs consumed in a given day. Moreover, treeshrews are difficult to observe in the wild, leading to a lack of observational data in the literature. Although treeshrews are mixed feeders, consuming both insects and fruit, it is currently unknown how the relative importance of these food types varies across Scandentia. Previous study of functional dental morphology has provided an alternative means for understanding the diet of living euarchontans. We used dental topographic metrics to quantify aspects of functional dental morphology in a large sample of treeshrews (n = 58). We measured relief index, Dirichlet normal energy, and three-dimensional orientation patch count rotated, which quantify crown relief, occlusal curvature, and complexity, respectively. Our results suggest that treeshrews exhibit dental morphology consistent with high levels of insectivory relative to other euarchontans. They also suggest that taxa such as Dendrogale melanura and Tupaia belangeri appear to be best suited to insectivory, whereas taxa such as T. palawanensis and T. gracilis appear to be best adapted to frugivory. Our results suggest that Ptilocercus lowii is characterized by a dentition better adapted to insectivory than the early primate Purgatorius. If P. lowii represents a good modern analogue for primitive euarchontans, this contrast would support models of primate origins that include a shift to greater frugivory.
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Affiliation(s)
- Keegan R Selig
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
| | - Eric J Sargis
- Department of Anthropology, Yale University, New Haven, CT 06520, USA
| | - Mary T Silcox
- Divisions of Vertebrate Zoology and Vertebrate Paleontology, Peabody Museum of Natural History, New Haven, CT, USA
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Selig KR, Sargis EJ, Silcox MT. Three-Dimensional Geometric Morphometric Analysis of Treeshrew (Scandentia) Lower Molars: Insight into Dental Variation and Systematics. Anat Rec (Hoboken) 2019; 302:1154-1168. [PMID: 30809964 DOI: 10.1002/ar.24105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 10/30/2018] [Accepted: 11/18/2018] [Indexed: 12/19/2022]
Abstract
Scandentia (treeshrews) is an order of small-bodied Indomalayan mammals generally agreed to be a member of Euarchonta with Primates and Dermoptera (colugos). However, intraordinal relationships among treeshrews are less well understood. Although recent studies have begun to clarify treeshrew taxonomy using morphological and molecular datasets, previous analysis of treeshrew dentition has yielded little clarity in terms of species-level relationships within the order. However, these studies made use of character-based methods, scoring traits across the dental arcade, which depend on there being clear differences among taxa that can be encapsulated in coding schemes. Geometric morphometrics has the potential to capture subtler shape variation, so it may be better for examining similarities among closely related taxa whose teeth have a similar bauplan. We used three-dimensional geometric morphometrics on a sample of treeshrew lower second molars and compared the patterns of variation to the results of previous studies. We captured 19 landmarks on a sample of 43 specimens representing 15 species. Using specimen-based principal components analysis and between-group principal component analysis, the two treeshrew families (Tupaiidae and Ptilocercidae) were well separated in morphospace. Moreover, several treeshrew species plot in morphospace according to the clades established in previous molecular work, with closely related species plotting closer to one another than to more distantly related species, suggesting that dental morphology can be useful when studying relationships among treeshrews. As most extinct treeshrews are known only from teeth, understanding morphological patterns in treeshrew molars is important for future work on the evolutionary history of Scandentia. Anat Rec, 302:1154-1168, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Keegan R Selig
- Department of Anthropology, University of Toronto, Scarborough, Toronto, Ontario, Canada
| | - Eric J Sargis
- Department of Anthropology, Yale University, New Haven, Connecticut.,Divisions of Vertebrate Zoology and Vertebrate Paleontology, Peabody Museum of Natural History, New Haven, Connecticut
| | - Mary T Silcox
- Department of Anthropology, University of Toronto, Scarborough, Toronto, Ontario, Canada
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Sargis EJ, Millien V, Woodman N, Olson LE. Rule reversal: Ecogeographical patterns of body size variation in the common treeshrew (Mammalia, Scandentia). Ecol Evol 2018; 8:1634-1645. [PMID: 29435239 PMCID: PMC5792578 DOI: 10.1002/ece3.3682] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 10/13/2017] [Accepted: 11/08/2017] [Indexed: 12/24/2022] Open
Abstract
There are a number of ecogeographical "rules" that describe patterns of geographical variation among organisms. The island rule predicts that populations of larger mammals on islands evolve smaller mean body size than their mainland counterparts, whereas smaller-bodied mammals evolve larger size. Bergmann's rule predicts that populations of a species in colder climates (generally at higher latitudes) have larger mean body sizes than conspecifics in warmer climates (at lower latitudes). These two rules are rarely tested together and neither has been rigorously tested in treeshrews, a clade of small-bodied mammals in their own order (Scandentia) broadly distributed in mainland Southeast Asia and on islands throughout much of the Sunda Shelf. The common treeshrew, Tupaia glis, is an excellent candidate for study and was used to test these two rules simultaneously for the first time in treeshrews. This species is distributed on the Malay Peninsula and several offshore islands east, west, and south of the mainland. Using craniodental dimensions as a proxy for body size, we investigated how island size, distance from the mainland, and maximum sea depth between the mainland and the islands relate to body size of 13 insular T. glis populations while also controlling for latitude and correlation among variables. We found a strong negative effect of latitude on body size in the common treeshrew, indicating the inverse of Bergmann's rule. We did not detect any overall difference in body size between the island and mainland populations. However, there was an effect of island area and maximum sea depth on body size among island populations. Although there is a strong latitudinal effect on body size, neither Bergmann's rule nor the island rule applies to the common treeshrew. The results of our analyses demonstrate the necessity of assessing multiple variables simultaneously in studies of ecogeographical rules.
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Affiliation(s)
- Eric J. Sargis
- Department of AnthropologyYale UniversityNew HavenCTUSA
- Division of Vertebrate ZoologyYale Peabody Museum of Natural HistoryNew HavenCTUSA
| | | | - Neal Woodman
- United States Geological SurveyPatuxent Wildlife Research CenterNational Museum of Natural HistorySmithsonian InstitutionWashingtonDCUSA
| | - Link E. Olson
- University of Alaska MuseumUniversity of Alaska FairbanksFairbanksAKUSA
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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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An early Oligocene fossil demonstrates treeshrews are slowly evolving "living fossils". Sci Rep 2016; 6:18627. [PMID: 26766238 PMCID: PMC4725336 DOI: 10.1038/srep18627] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 11/19/2015] [Indexed: 11/24/2022] Open
Abstract
Treeshrews are widely considered a “living model” of an ancestral primate, and have long been called “living fossils”. Actual fossils of treeshrews, however, are extremely rare. We report a new fossil species of Ptilocercus treeshrew recovered from the early Oligocene (~34 Ma) of China that represents the oldest definitive fossil record of the crown group of treeshrews and nearly doubles the temporal length of their fossil record. The fossil species is strikingly similar to the living Ptilocercus lowii, a species generally recognized as the most plesiomorphic extant treeshrew. It demonstrates that Ptilocercus treeshrews have undergone little evolutionary change in their morphology since the early Oligocene. Morphological comparisons and phylogenetic analysis support the long-standing idea that Ptilocercus treeshrews are morphologically conservative and have probably retained many characters present in the common stock that gave rise to archontans, which include primates, flying lemurs, plesiadapiforms and treeshrews. This discovery provides an exceptional example of slow morphological evolution in a mammalian group over a period of 34 million years. The persistent and stable tropical environment in Southeast Asia through the Cenozoic likely played a critical role in the survival of such a morphologically conservative lineage.
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Woodman N, Stabile FA. Variation in the myosoricine hand skeleton and its implications for locomotory behavior (Eulipotyphla: Soricidae). J Mammal 2015. [DOI: 10.1093/jmammal/gyu017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Woodman N, Stabile FA. Functional skeletal morphology and its implications for locomotory behavior among three genera of myosoricine shrews (Mammalia: Eulipotyphla: Soricidae). J Morphol 2015; 276:550-63. [DOI: 10.1002/jmor.20365] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 12/09/2014] [Accepted: 12/19/2014] [Indexed: 11/05/2022]
Affiliation(s)
- Neal Woodman
- Department of Vertebrate Zoology, USGS Patuxent Wildlife Research Center, National Museum of Natural History; Smithsonian Institution; Washington, DC 20013-7012
| | - Frank A. Stabile
- Department of Biology; The College of New Jersey; Ewing New Jersey 08628
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Sargis EJ, Woodman N, Morningstar NC, Reese AT, Olson LE. Island history affects faunal composition: the treeshrews (Mammalia: Scandentia: Tupaiidae) from the Mentawai and Batu Islands, Indonesia. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eric J. Sargis
- Department of Anthropology; Yale University; PO Box 208277 New Haven CT 06520 USA
- Department of Ecology and Evolutionary Biology; Yale University; PO 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
| | | | - Aspen T. Reese
- Department of Ecology and Evolutionary Biology; Yale University; PO Box 208106 New Haven CT 06520 USA
- Division of Vertebrate Zoology; Yale Peabody Museum of Natural History; New Haven CT 06520 USA
| | - Link E. Olson
- University of Alaska Museum; University of Alaska Fairbanks; Fairbanks AK 99775 USA
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Sargis EJ, Woodman N, Morningstar NC, Reese AT, Olson LE. Morphological distinctiveness of JavanTupaia hypochrysa(Scandentia, Tupaiidae). J Mammal 2013. [DOI: 10.1644/13-mamm-a-042.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Sargis EJ, Campbell KK, Olson LE. Taxonomic Boundaries and Craniometric Variation in the Treeshrews (Scandentia, Tupaiidae) from the Palawan Faunal Region. J MAMM EVOL 2013. [DOI: 10.1007/s10914-013-9229-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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