福井県有恐竜化石出土

Last month the Yomiuri News on-line reported the following:

福井県勝山市の県立恐竜博物館は２４日、同市内の約１億２０００万年前（白亜紀前期）の地層から、「ダチョウ型恐竜」と呼ばれるオルニトミモサウルス類の指の骨の化石３点が見つかったと発表した。

　国内では群馬、熊本両県に次いで３例目。今回の化石が最古級とみられ、東洋一・特別館長（６３）は「当時日本に広く生息したことを示す貴重な資料」としている。

　同館の研究員が１９９８年と２００８年に発見した前脚の指先の骨（長さ３・５～４・６センチ）３点を鑑定し、いずれも細長く平らな形の特徴からオルニトミモサウルス類と判断した。体長は約１・６メートルとみられる。

　オルニトミモサウルス類は長い首、長い後脚などダチョウに似た特徴があり、群れで生活する雑食性の恐竜。肉食恐竜から逃げるために後脚が発達し、時速７０キロ以上で走る種もいたとされる。映画「ジュラシック・パーク」にも登場し、「最も足の速い恐竜」として知られる。

（2013年6月24日22時14分 読売新聞）

(試譯文)

It was announced by the prefecture dinosaur museum in Katsuyama-shi, Fukui on the 24^th (June) that the three pieces of fossil, discovered in the city from the stratum about 120 million years ago (Lower Cretaceous), were found to be the finger bones of the Ornithomimosauria type, the so called "ostrich type dinosaur".

In Japan it was the third fossil sample, following Gumma and Kumamoto prefectures. The fossils were regarded as the oldest class. Special superintendent Azumayo Ichi (63) took it as “precious data which show that at that time they had lived extensively".

The researcher of the museum used the bones of the fingertip of the forelimb discovered in 1998 and 2008 (3.5 to 4.6 cm in length) to identify the three pieces, and judged that all should be Ornithomimosauria, based on the feature of having long, slender and even form. The body length was observed to be about 1.6 meters.

Ornithomimosauria were omnivorous dinosaurs which were having a feature similar to ostriches, such as the long head and long hind legs, and lived in groups. In order to escape from the meat-eating dinosaur, hind legs developed. It was supposed that this species could run at 70 km/h or more. It appeared in the movie the "Jurassic Park" and was known as "the swiftest-running dinosaur".

It is an interesting discovery. It will increase our understanding about the dinosaurs in Japan.