1 0 0 0 OA ミャンマー中部の新第三系イラワジ動物相:食肉目
- 著者
- 江木 直子 荻野 慎諧 高井 正成
- 出版者
- 日本古生物学会
- 雑誌
- 化石 (ISSN:00229202)
- 巻号頁・発行日
- vol.104, pp.21-33, 2018-09-30 (Released:2019-04-03)
We report occurrences of carnivorans from the Irrawaddy beds in central Myanmar. Intensive expeditions in the recent decade improved understandings on biostratigraphic position of each fauna within the Irrawaddy beds (Late Miocene to Early Pleistocene) and brought out discovery of carnivoran specimens. An amphicyonid has been collected from the Tebingan locality, near the basal horizon (Late Miocene) of the Irrawaddy beds. This large animal is considered to be a new genus endemic to Myanmar. The Chaingzauk fauna (around the Miocene/Pliocene boundary) yields the most abundant remains: An ailurid (Simocyon), a large ursid (Agriotherium), a saber-tooth felid (Homotherium), at least three species of hyaenids including a primitive subfamily member (Ictitherium), a running form (Hyaenictis), and a wolf-like form (Hyaenictitherium). The fauna consists of medium to gigantic forms; sampling biases seem to influence collection of carnivorans as well as those of other mammals. All of these carnivoran genera have cosmopolitan distributions, and the occurrences from Myanmar fill their geological gap at Southeast Asia within Eurasia. Additionally, an indeterminate feliform was collected from the fauna. The Gwebin fauna (Late Pliocene) include a herpestid (Urva), a medium-sized felid, and a viverrid (Viverrinae). This first record of herpestid in the Pliocene of Asia confirms that the extant Asian mongoose lineage had already dispersed into Southeast Asia from South Asia by the Late Pliocene. Postcranial materials from the Sulegon area (Pliocene) provide evidences of additional taxa, a small felid and a large hyaenid. These recently collected carnivoran specimens revealed presence of diverse carnivorans from the Irrawaddy faunas. They fill geographical and/or chronological gaps of carnivoran distributions in Southeast Asia. Furthermore, the comparisons among carnivoran assemblages indicate faunal turnover of carnivorans at the family or subfamily level from the Late Miocene to the Late Pliocene of Myanmar.