·科学·
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10,000-Year-Old Mastodon Tooth Discovered in California

カリフォルニア州で1万年前のマストドンの歯を発見

#mastodon#california#fossil#paleontology#ice age
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A scientist in California recently found a 10,000-year-old tooth from an ancient animal called a Pacific mastodon. Brigid Lynch, an earth scientist, noticed the unusual object while working at a nature preserve in San Mateo County. Paleontologists, who are experts that study ancient life, confirmed that it was a well-preserved adult mastodon molar, or back tooth.

who are experts that study ancient life= 専門用語(古生物学者)の意味を補足説明する関係代名詞節

Pacific mastodons were large plant-eating mammals related to modern elephants. They lived in North America for about 2.5 million years, especially in western areas such as California and Oregon. However, the species went extinct more than 10,000 years ago because climate change damaged their habitat and humans hunted them.

related to= 進化上の系統や血縁関係があることを示す表現went extinct= 種が完全に全滅・絶滅した状態になること

The tooth was donated to Stanford University, where researchers will use carbon dating to determine its exact age. Scientists say that studying fossils helps them understand past wildlife and environments, which can help people protect modern ecosystems in the future.

B2

A scientist working at a nature preserve in San Mateo County, California, has discovered a remarkably well-preserved fossilized tooth belonging to an ancient Pacific mastodon. Geomorphologist Brigid Lynch initially spotted what appeared to be a peculiar rock. Paleontologists later confirmed that the object was an adult mastodon molar, with expert Wayne Thompson calling it the most complete mastodon molar ever found in the region.

belonging to= 特定の動物や所有者に帰属・所有されていたことを示す表現what appeared to be= 一見〜のように見えたもの(詳細な確認前の外観を表す)with expert Wayne Thompson calling it= 専門家のコメントや補足情報を添える「with + 名詞 + 分詞」の表現

Pacific mastodons were large herbivorous mammals closely related to modern elephants. The species inhabited North America for about 2.5 million years, roaming across the American West, including present-day California, Oregon, and parts of Mexico. They disappeared more than 10,000 years ago due to climate change affecting their habitat alongside pressure from human hunting.

roaming across= 広大な地域を自由に移動・徘徊することalongside pressure from= 〜からの圧力や影響と並行して・同時に

The fossilized molar has been donated to Stanford University, where researchers will employ carbon dating to determine its exact age. Christine Garcia, a curator at Stanford, noted that fossils provide a unique opportunity to study past biodiversity, which can guide better decisions for protecting ecosystems today.

where researchers will employ= 先行詞(スタンフォード大学)での研究活動を説明する関係副詞which can guide better decisions= 過去の理解が将来の意思決定に役立つという関係を示す非制限用法の関係代名詞

The find is part of several recent mastodon fossil discoveries across the United States. In 2024, a New York resident found a mastodon jaw beneath their lawn, a year after a woman discovered a foot-long mastodon tooth on a central California beach.

a year after= ある出来事の1年後に別の出来事が起きたという時間経過を示す表現

学習ノート

表現パターン

パターン意味
who are experts that study ancient life専門用語(古生物学者)の意味を補足説明する関係代名詞節
related to進化上の系統や血縁関係があることを示す表現
went extinct種が完全に全滅・絶滅した状態になること
belonging to特定の動物や所有者に帰属・所有されていたことを示す表現
what appeared to be一見〜のように見えたもの(詳細な確認前の外観を表す)
with expert Wayne Thompson calling it専門家のコメントや補足情報を添える「with + 名詞 + 分詞」の表現
roaming across広大な地域を自由に移動・徘徊すること
alongside pressure from〜からの圧力や影響と並行して・同時に
where researchers will employ先行詞(スタンフォード大学)での研究活動を説明する関係副詞
which can guide better decisions過去の理解が将来の意思決定に役立つという関係を示す非制限用法の関係代名詞
a year afterある出来事の1年後に別の出来事が起きたという時間経過を示す表現

語彙

語意味
herbivorous植物だけを食べる;草食性の
fossilized化石化した;化石になった
molar哺乳類の口の奥にある、食べ物をすりつぶす歯の;臼歯の
habitat動植物が自然の状態で生息する場所や環境。
biodiversityある地域や地球全体に存在する、植物・動物など生物の多様性。

言語メモ

  • •「マストドン(mastodon)」という名前はギリシャ語の「乳頭状の歯」に由来しており、マンモスと異なり臼歯の表面に突起がある特徴的な形をしていることから名付けられました。
  • •科学ニュースで頻出する「carbon dating(放射性炭素年代測定)」は、約5万年前までの有機物の年代を測定するための標準的な手法です。

練習

読んだ内容を確認しましょう。

  1. Pacific mastodons were large   mammals closely related to modern elephants.

  2. Where will researchers test the mastodon tooth using carbon dating?

Source: The Guardian World