中世は北極の春で終わりました
Melanie A D During1,2, Jan Smit3, Dennis F A E Voeten4,5
1Department of Earth Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands. melanie.during@ebc.uu.se.
Nature
|February 24, 2022
まとめ
クレタセウス・パラエオゲンの大量絶滅を引き起こしたチクスルブ小惑星の衝突は,北極の春に起こった. この季節的なタイミングが 絶滅に生き残った種に影響を与えました
科学分野:
- 古生物学
- 地質学
- 気候科学
背景:
- 約6600万年前のクレタセウス・パラエオゲン (K-Pg) 大量絶滅は主にチクスルブ小惑星の衝突によって引き起こされた.
- この絶滅は,鳥類以外の恐竜,ペトロサウルス,海洋爬虫類を含む全種の約76%の絶滅をもたらした.
- 過去の研究は主にミレニアムスケールに焦点を当てており 衝撃の正確な時期は未定でした
研究 の 目的:
- シクスルーブ小惑星の衝突の時期を 特定するためです
- K-Pg絶滅の際に選択的な種の生存に 衝撃のタイミングが及ぼす影響を調査する.
主な方法:
- タニスの衝突堆積物から特異的に保存されたアシペンセリフォーム魚の分析
- 骨組織学と化石骨から 安定した同位体の記録を用いて
- 繁殖と冬眠/静止パターンを含む魚のライフサイクルにおける年間周期性を調べる.
主要な成果:
- 化石の証拠は,北極の春の間に Chicxulub 衝突が発生したことを示しています.
- クレタセア期末には様々な生物の生周期が季節的に大きく変化した.
- 北極の春 (南極の秋) の衝突のタイミングは,異なる種の生存の重要な要因として仮定されています.
結論:
- チクスルブ衝突は北極の春に起こった.
- 衝撃の季節的なタイミングは,白亜紀・古亜紀の大量絶滅の選択性において重要な役割を果たした.
- 季節的な影響のダイナミクスを理解すると,K-Pgの絶滅の選択性に関する新しい洞察が得られます.
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