Big-headed turtle

A turtle of the family Testudinidae in the order Testudins. It is also called the giant turtle. It is found in southern Myanmar (Burma), Thailand, Indochina, and southern China. It is sometimes treated as an independent family, but is often included in the family Testudinidae due to the structure of its skull and other parts. Its carapace is 18 cm long, its carapace is flat, and its tail is as long as the carapace. Its head is large, about half the length of the carapace, and it cannot be retracted into the carapace. However, its head, legs, and tail are protected by thick keratinous scales. It has sharp claws on each finger and uses them to climb rocks and trees. It has only four toes on its hind legs. It lives in mountain streams, and feeds on small fish, snails, earthworms, etc. When it encounters danger, it covers its eyes with a white nictitating membrane, opens its beak-like mouth, and makes a hissing sound to scare away prey. It lays two eggs at a time.

[Takahiro Matsui]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

爬虫(はちゅう)綱カメ目カミツキガメ科のカメ。オオクビガメともよばれる。ミャンマー（ビルマ）南部、タイ、インドシナ、中国南部に分布する。独立の科として扱うこともあるが、頭骨などの構造からカミツキガメ科に含まれることが多い。甲長18センチメートル、背甲が平たく、尾は甲長と同じぐらい長い。頭部は大きくて甲長の半分ほどもあり、甲内に引っ込めることができない。しかし頭、四肢、尾は角質の厚い鱗(うろこ)で守られている。各指には鋭いつめがあって岩や木によじ登る。後肢の足指は4本しかない。山地の渓流にすみ、餌(えさ)は小魚、巻き貝、ミミズなどである。危険に出会うと白い瞬膜で目を覆い、嘴(くちばし)状の口を開いてシューシューと音をたてて脅かす。卵は一度に2個産む。

［松井孝爾］

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