Masaharu Motokawa

A comprehensive morphological analysis of talpid moles (Mammalia) phylogenetic relationships

Some talpid moles show one of the most specialized suites of morphological characters seen among small mammals. Fossorial and more generalized shrew‐looking moles inhabit both North America and Eurasia but these land masses share none of the same genera. One of the central questions of mole evolution has been that of how many times specialized fossorial habits evolved. We investigated the origin of mole characters with a maximum parsimony analysis of 157 characters, mostly craniodental and postcranial, of representatives of all 17 living mole genera and three shrews and one hedgehog as outgroups. The result was one most‐parsimonious tree and its most novel aspect was the position of a Japanese shrew mole clade (Urotrichus, Dymecodon), which branched off after Uropsilus and was not closely related to the American shrew mole (Neurotrichus). The desmans (Galemys and Desmana) were the next clade in the tree, followed by Neurotrichus. We confirmed the monophyly of the Eurasian fossorial mole clade Talpini (Euroscaptor, Parascaptor, Mogera, Scaptochirus and Talpa). Condylura, the star‐nosed mole from North America, was sister group to a clade consisting of the Talpini plus Scaptonyx and the Scalopini (Scalopus, Scapanus, Parascalops, and Scapanulus). Based on our results and on the assumption that moles originated in Eurasia, it is most parsimonious to infer one migration from Eurasia to North America and two back‐migrations to Eurasia. It is ambiguous if Talpini and Scalopini evolved their full fossorial habits independently or not.

Phylogenetic relationships within the family Talpidae (Mammalia : Insectivora)

The phylogenetic relationships within the family Talpidae (Mammalia, Insectivora) were inferred from parsimonious analysis of 55 morphological characters, which were collected from 43 skulls of 22 species, and which included all of the extant genera in the current taxonomy of the Talpidae. Two equally parsimonious cladograms were obtained. The Uropsilinae, Desmaninae and Talpinae subfamilies formed monophyletic clades, and the Desmaninae and Talpinae subfamilies were sister clades. The Talpinae subfamily was subdivided into the following clades: Urotrichus , Dymecodon , Scalopus – Scapanus , Parascalops – Scapanulus , Condylura , Neurotrichus , Scaptonyx and Talpini ( Talpa , Euroscaptor , Scaptochirus , Parascaptor and Mogera ). The Urotrichini ( Urotrichus , Dymecodon and Neurotrichus ) and Scalopini ( Scalopus , Scapanus , Parascalops and Scapanulus ) were considered to be paraphyletic, and were defined primarily by their ancestral characteristics. Since the genus Dymecodon was not clustered with Urotrichus , it was considered to be a valid genus, and not just a junior synonym of the latter. The Asian genus Euroscaptor was found to be a paraphyletic group, and deserves further systematic revision. The evolution from semi-fossorial habit to fully fossorial habit seems to have occurred three times in the Scalopus – Scapanus , Parascalops – Scapanulus and Talpini clades. The migration of the Talpinae to North America from Eurasia probably occurred on four separate occasions in the Scalopus–Scapanus , Parascalops , Condylura and Neurotrichus lineages.

Taxonomic status of the Senkaku mole, Nesoscaptor uchidai, with special reference to variation in Mogera insularis from Taiwan (Mammalia : Insectivora)

Abstract The taxonomic status of the Senkaku mole,Nesoscaptor uchidai Abe, Shiraishi et Arai, 1991 (Mammalia: Insectivora: Talpidae), described from Uotsurijima in the Senkaku Group, Ryukyu Archipelago, was re-evaluated. Morphological analyses suggest that N. uchidai is most similar to Mogera insularis from Taiwan, although several morphological characters, such as the number of premolars and the shapes of the anterior portion of the palate, zygomatic arch, auditory bulla, and coronoid process, differentiate N. uchidai from M. insularis. Therefore, we synonymize the monotypic genus Nesoscaptor Abe, Shiraishi et Arai, 1991 with the genus Mogera Pomel, 1848, and define Mogera uchidai (Abe, Shiraishi et Arai, 1991) as a valid species endemic to Uotsurijima. In addition, we analyzed morphological variation within M. insularis, such as variation in the second upper premolar pair, overall cranial size, and the breadth of the rostrum and palate. Some of this variation may be associated with topographical and environmental factors in its habitat.

Taxonomy of Rhinolophus yunanensis Dobson, 1872 (Chiroptera: Rhinolophidae) with a Description of a New Species from Thailand

The taxonomy of Rhinolophus yunanensis Dobson, 1872 (Chiroptera: Rhinolophidae) is revised by reference to specimens collected from the provinces of Sichuan and Yunnan, China, and from Thailand. The Thai specimens are found to differ from the Chinese ones in external and cranial morphology and karyotype, and it is thus concluded that what has hitherto been R. yunanensis actually represents two distinct species, including a new one. The new species is described on the basis of 10 specimens collected from Chiang Mai, Thailand. It is the largest species of the pearsoni group of the genus, with a large skull and long ears. Rhinolophus yunanensis is redescribed on the basis of specimens collected from China. In Principal Component Analyses of the cranial morphometric data, the new species was completely separated from the redescribed R. yunanensis and R. pearsoni.

Chromosomal polymorphism in the gray shrew Crocidura attenuata (Mammalia : Insectivora)

Abstract Conventional and G-banded karyotypes of Crocidura attenuata Milne-Edwards, 1872 from Guangdong, southern China, are reported. The diploid chromosome number (2n) varied from 35 to 38 among specimens, while the fundamental arm number (FN) consistently was 54. Of the autosomes, 14 pairs including four meta- or submetacentric, three subtelocentric, and seven acrocentric pairs showed no variation in all specimens, whereas the remaining pairs showed Robertsonian polymorphism. The X and Y chromosomes were medium sized submetacentric and small acrocentric chromosomes, respectively. These karyotypes differ from that of C. attenuata from Taiwan, which has 40 chromosomes with 56 arms. Such differences are largely attributable to a non-Robertsonian rearrangement, where both 2n and FN values are different from each other. The largest metacentric pair observed in karyotypes from Guangdong may have resulted from the centromere-telomere translocation between an acrocentric and a subtelocentric pairs of karyotype homologous to that from Taiwan. Both morphometric difference and sequence divergence in mitochondrial cytochrome b gene between samples from Guangdong and Taiwan was relatively small. However, the nonRobertsonian rearrangement assumed between karyotypes of the shrews from Guangdong and Taiwan suggest that they are reproductively isolated from each other. The eastern continental and Taiwanese populations therefore may represent different species under the names, C. attenuata (sensu stricto), and C. tanakae Kuroda, 1938, respectively.

Allometric Comparison of Skulls from Two Closely Related Weasels, Mustela itatsi and M. sibirica

We conducted an interspecific comparison of skulls from two closely related but differently sized mustelid species, Mustela itatsi and M. sibirica (Mammalia, Carnivora, Mustelidae); a sexual comparison within the latter species showed remarkable size dimorphism. We clarified several differences in skull proportion related to size using allometric analyses and qualitative comparisons. Allometric analysis revealed that the skulls of male M. itatsi (the smaller species) have a relatively long palate; a slender viscerocranium and postorbital constriction; a broad, short, and low neurocranium; small carnassials; and a short mandible with a thin body and small ramus compared to the skulls of male M. sibirica (the larger species). Similar results were obtained when male M. itatsi were compared to female M. sibirica, although the male M. itatsi had a broader viscerocranium than female M. sibirica. A sexual comparison in M. sibirica revealed a larger skull size among the males with a relatively wide viscerocranium; wide postorbital constriction; a slender, long, and high neurocranium; short and wide auditory bullae; short carnassials; and a long and high mandible compared to females. Qualitative comparisons revealed changes in a few characters depending on skull size or with respect to some cranial components in each species. The interspecific differences observed were clearly larger than the intraspecific differences for three qualitative characters. The allometric and qualitative differences detected between these species suggest that each species is not simply the dwarf and/or giant morph of the other, and complicated differences were clarified.

Geographic variation in morphological traits of the large Japanese field mouse, Apodemus speciosus (Rodentia, Muridae), from the Izu Island Group, Japan

We investigated geographic variation in morphological traits of the large Japanese field mouse (Apodemus speciosus) from the Izu Island Group, Japan. There was sexual dimorphism in external characters and cranial measurements; hence, these were considered in subsequent analyses. There was geographic divergence in morphometric characters among populations of the Izu Island Group and Honshu. Mice from the Miyakejima Island and Niijima-Shikinejima Islands differed from those of other populations and from each other; Oshima Island mice also differed, but to a lesser degree. Mice from three populations from Honshu were similar to one another, and mice from Kozushima Island were more similar to those from Honshu populations than those from Izu Island Group populations. These results suggest that A. speciosus populations in the Izu Island Group may have had multiple origins. One possible hypothesis to explain these patterns of variation is that the Miyakejima, Niijima, and Shikinejima populations may share a relatively longer history of overseas dispersal, whereas the Kozushima populations may have experienced a recent invasion from Honshu via human activities.

Morphometric Geographic Variation in the Asian Lesser White-Toothed Shrew Crocidura shantungensis (Mammalia, Insectivora) in East Asia

Abstract This study investigated geographic variation in the Asian lesser white-toothed shrew, Crocidura shantungensis Miller, 1901, among a number of localities in East Asia, including the Korean Peninsula, Tsushima Island, Cheju Island, and Taiwan, using univariate and multivariate analyses of cranial morphometric characters. Sexual differences were found in Taiwanese shrews, but were not evident in those from Korea or Tsushima. The samples from Taiwan had a larger overall cranial size than those from Korea and Tsushima, and were well separated from the latter two samples in the discriminant analyses. The overall size of the Cheju shrews was also greater, but lay within the variation of those from Taiwan. Crocidura dsinezumi quelpartis Kuroda, 1934, described from Cheju Island, is actually a junior synonym of C. shantungensis, and is not related to C. dsinezumi.

New Records of Kerivoula titania (Chiroptera: Vespertilionidae) from Hainan Island and Taiwan

The genus Kerivoula includes about 20 species, and 12 species have been recorded in the Indomalayan Region, including recently described species such as K. kachinensis from northern Myanmar, K. krauensis from Peninsular Malaysia, and K. titania from Southeast Asia (Corbet and Hill 1992; Bates et al. 2004, 2007; Simmons 2005; Thong et al. 2006; Francis et al. 2007). Among them, K. titania was recently described by Bates et al. (2007) from the Seima Biodiversity Conservation Area, Cambodia, and it is widely distributed in mainland Southeast Asia in 13 localities in five countries: Myanmar, Thailand, Lao PDR, Cambodia, and Vietnam (Bates et al. 2007). Only two Kerivoula bats have been recorded from China, K. picta and K. hardwickii (Zhang 1997; Wang 2003). Recently, we collected eight specimens identified as K. titania for the first time from Hainan Island and Taiwan as reported below.

The reds and the yellows: a review of Asian Chrysopteron Jentink, 1910 (Chiroptera: Vespertilionidae: Myotis)

Abstract Chrysopteron Jentink, 1910 is 1 of the 7 subgenera of Myotis Kaup, 1829 recognized by Tate that traditionally comprises Asian and African species characterized by conspicuously parti-colored wing membranes. Definition of Myotis subgenera has long challenged taxonomists and prior to the present study the systematic status of numerous forms within Chrysopteron remained unclear. Following examination of material (including available type specimens) in 21 European, North American, and Asian collections, and using morphological (external, cranial, and dental characters) and genetic data, we evaluate the validity of the Chrysopteron subgenus, revise the taxonomy of the named Asian forms, and review their distinguishing characters, distribution, and taxonomic history. We argue that Chrysopteron is an available name for a monophyletic “Ethiopian clade” recovered with high support in our analyses, which comprises species characterized by striking reddish or yellowish dorsal fur that strongly differentiates them from congeners. We also determine that M. formosus sensu lato contains several morphologically distinct forms, some of which occur in sympatry and some in widely separated localities. A morphological key is provided for all Asian species of Chrysopteron revealed by our study: M. bartelsi Jentink, 1910 (Java and Bali), M. formosus (Hodgson, 1835) (Afghanistan, India, Nepal, China, Taiwan, and Vietnam), M. hermani Thomas, 1923 (Sumatra, Thailand, and Malaysia), M. rufoniger (Tomes, 1858) (Korea, Japan, China, Taiwan, Laos, and Vietnam), M. rufopictus (Waterhouse, 1845) (Philippines), and M. weberi (Jentink, 1890) (Sulawesi).