Tuesday, February 14, 2017

[Mammalogy • 2017] Comparative Phylogeography of Bamboo Bats of the Genus Tylonycteris (Chiroptera, Vespertilionidae) in Southeast Asia; Revalidation of T. fulvida & T. malayana and Description of A New Species, T. tonkinensis, endemic to northern Indochina


Tylonycteris tonkinensis  
 Tu, Csorba, Ruedi & Hassanin, 2017

 DOI:  10.5852/ejt.2017.274 

Abstract 

In Southeast Asia, bats of the genus Tylonycteris Peters, 1872 have traditionally been classified into two wide-ranging species, T. pachypus (Temminck, 1840) and T. robustula Thomas, 1915. Our comparative phylogeographic analyses based on two mitochondrial and seven nuclear genes, combined with our multivariate morphological analyses, show that these species actually represent cryptic species complexes that share a similar biogeographic history in three major regions, i.e., Sundaland, southern Indochina, and northern Indochina. Our molecular dating estimates suggest that Pleistocene climatic oscillations and sea level changes have repeatedly isolated ancestral populations of Tylonycteris spp. in distant bamboo forest refugia. The analyses indicate, however, that populations of the T. pachypus complex were less affected by forest fragmentation in mainland Southeast Asia than those of the T. robustula complex. Accordingly, we propose several taxonomic changes within the genus Tylonycteris: the species T. fulvida and T. malayana are revalidated, and a new species, Tylonycteris tonkinensis Tu, Csorba, Ruedi & Hassanin sp. nov., endemic to northern Indochina, is described.

Keywords: Vespertilioninae; Tylonycteris; DNA phylogeny; taxonomy; biogeography


T. robustula Thomas, 1915 (corrected taxon name is Tylonycteris tonkinensis Tu, Csorba, Ruedi & Hassanin sp. nov.), holotype, IEBR-VN11-0055. Head profiles, ventral and dorsal views, fleshy pads at the base of the thumb and on the sole of the foot, and different views of the skull (dorsal, ventral and lateral). Scale = 10 mm.  

Phylum Chordata Haeckel, 1874
Class Mammalia Linnaeus, 1758
Order Chiroptera Blumenbach, 1779

Family Vespertilionidae Gray, 1821
Subfamily Vespertilioninae Gray, 1821

Tylonycteris tonkinensis Tu, Csorba, Ruedi & Hassanin sp. nov.
Tylonycteris robustula Thomas, 1915 (partim): 227.
Tylonycteris robustula – Osgood 1932: 236. — Tate 1942: 268. — Hendrichsen et al. 2001: 90. —
Kruskop 2013: 221. — Thomas et al. 2013: 229.

Etymology: The specific epithet refers to the current restricted occurrence of the new species in north-eastern Laos and northern Vietnam (Fig. 1). The Vietnamese portion of this region was previously called “Tonkin” during the Nguyễn dynasty and French colonial era (from the 19th to the mid-20th centuries) to separate it from the country’s centre (Annam) and southern regions (Cochinchina). The proposed English name is “Tonkin’s Greater Bamboo Bat” and the proposed Vietnamese name is ‘Dơi ống tre Bắc Bộ’.

Fig. 5. Morphological characteristics of the two nominal species of the genus Tylonycteris Peters, 1872.
 A. T. pachypus (Temminck, 1840) (corrected taxon name is T. fulvida (Blyth, 1859)), IEBR-VN11- 0015. B. T. robustula Thomas, 1915 (corrected taxon name is Tylonycteris tonkinensis Tu, Csorba, Ruedi & Hassanin sp. nov.), holotype, IEBR-VN11-0055. Head profiles, ventral and dorsal views, fleshy pads at the base of the thumb and on the sole of the foot, and different views of the skull (dorsal, ventral and lateral). Scale = 10 mm. 

Vuong Tan TU, Gábor CSORBA, Manuel RUEDI, Neil M. FUREY, Nguyen Truong SON, Vu Dinh THONG, Céline BONILLO and Alexandre HASSANIN. 2017. Comparative Phylogeography of Bamboo Bats of the Genus Tylonycteris (Chiroptera, Vespertilionidae) in Southeast Asia. European Journal of Taxonomy. 274: 1–38. DOI:  10.5852/ejt.2017.274


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