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最も古い3次元で保存された脊椎動物の脳脳
Richard P Dearden1,2, Agnese Lanzetti3,4, Sam Giles3,4
1School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham, UK. r.dearden@bham.ac.uk.
Nature
|September 21, 2023
まとめ
エリプティキウス・アメリカナスの化石は,初期のグナトストーム (状の脊椎動物) の頭蓋骨の解剖学を示しています. 現代の脊椎動物とは異なり 神経頭蓋骨には 軟骨が合わさず 脊椎動物の進化の初期に 洞察力を与えました
科学分野:
- 古生物学
- 進化生物学
- 比較解剖学
背景:
- 脊椎動物の神経頭蓋骨は 進化の鍵となる技術革新ですが 初期の発達については ほとんど理解されていません
- グナトストーム (の脊椎動物) とサイクロストーム (のない脊椎動物) の間には重要な形態学的違いがある.
- 初期の脊椎動物の化石と 保存状態の良い3次元の神経頭蓋骨の間にはかなりの時間隔があり 進化論の研究を妨げています
研究 の 目的:
- オルドビキアの幹群の骨格構造を記述する エリプティキウス・アメリカヌス
- グナトストーム神経の進化の起源を調査する
- 脊椎動物の頭部進化の理解における ギャップを埋めるため
主な方法:
- エリプティキウス・アメリカナスの化石のコンピュータトモグラフィー (CT) スキャン.
- 保存された頭蓋骨の細部分析
- 現存する脊椎動物と化石を比較した解剖学的研究.
主要な成果:
- エリプティキウス・アメリカナスは 感覚器官と脳を囲む対称な前頭蓋骨を持っています
- エリプティキウス・アメリカンスの脳は 単一のユニットに溶けませんでした これはグナトストームに由来する特徴を示唆しています
- 神経頭蓋骨は皮膚の骨格と脳の間の空間を満たし,いくつかの化石のを持つ脊椎動物と似ていますが,サイクロストームとは違います.
結論:
- エリプティキウス・アメリカナスは 初期のグナトストームの解剖学に関する 重要な洞察力を提供します
- ニューロクロニアル軟骨の 融合されていない性質は グナトストーム内の原始的な状態を強調しています
- この発見は 脊椎動物の頭部進化の理解を 大きく前進させました
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