恐竜のコプロライトと草と草食動物の初期の進化
Vandana Prasad1, Caroline A E Strömberg, Habib Alimohammadian
1Birbal Sahni Institute of Palaeobotany, Lucknow-226 007, India.
Science (New York, N.Y.)
|November 19, 2005
まとめ
インドからの化石化した植物証拠は,様々な草 (Poaceae) がクレタセア後期ゴンドワナに存在していたことを明らかにしています. これは,インド以前に草が多様化したことを示唆しています.
科学分野:
- パレオボタニーは古植物学です.
- パレオントロジー・パレオントロジー
- 進化生物学の進化生物学について
背景:
- 植物石は植物から採取された微小のシリカ体であり,過去の植生に関する洞察を提供している.
- コプロライトは,草食動物の食生活と古代の生態系で利用可能な植物の直接的な証拠を提供します.
- クレタ紀後期は,草を含む開花植物の多様化にとって重要な時期でした.
研究 の 目的:
- コプロライトの植物石分析を用いて,白亜紀後期におけるインド亜大陸における草 (Poaceae) の存在と多様性を調査する.
- 疑われるタイタノサウルスのサウロポッドの糞の生産者の食事を再構築するために.
- ゴンドワナテリアン哺乳類の食生活に関する仮説を評価する.
主な方法:
- インドで発見された化石化した恐竜コプロライトからの植物石の抽出と識別.
- 抽出された植物石の顕微鏡分析と分類分類.
- 特定された植物石と既知の植物分類,特に草の比較.
主要な成果:
- 少なくとも5つの草 (Poaceae) のサブクラードが特定され, Late Cretaceous Indiaにおける草の有意な多様性を示した.
- また,二コチレドン,コニファー,ナツメヤシの植物石も発見され,コプロライト生産者の多様な食生活を示唆しています.
- この発見は,多様な植物の存在とタイタノサウルスのサウロポッドの無差別な食習慣を裏付けている.
結論:
- 冠群の草 (Poaceae) は,インドの孤立前にゴンドワナに多様化し,広がっていた.
- タイタノサウルスのサウロポッドは,草,二葉植物,コニファー,ナツメなど,幅広い種類の植物を食べていた.
- このデータは,ヒプソドント歯を持つゴンドワナテリアン哺乳類が草食動物であったという仮説を裏付けている.
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