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ナミビアのナマ群のプロトゾーイモジュール生物鉱物化メタゾーン
Rachel A Wood1, John P Grotzinger, J A D Dickson
1Schlumberger Cambridge Research, High Cross, Madingley Road, Cambridge CB2 OEL, UK. rwood2@cambridge.scr.slb.com
まとめ
ナミビアで5億4千9百万年前の大きな,完全に生物鉱物化したメタゾーンであるNamapoikia rietoogensisが発見されました. この発見は,プロテロゾーイク時代の複雑で鉱物化された動物の生命のタイムラインを後退させます.
科学分野:
- パレオントロジー・パレオントロジー
- バイオミネラライゼーション
- プロテロゾーイクイオン (Proterozoic Eon) とは
背景:
- ナミビアのナマ群には,重要なプロテロゾイク時代の化石が保存されています.
- 初期の動物の生命と生物鉱物化の進化を理解することは極めて重要です.
研究 の 目的:
- 新しく発見された,巨大で,完全に生物鉱物化された,プロテロゾーイク時代のメタゾアンを記述する.
- 初期の動物の進化のタイムラインに対するこの発見の意味を決定する.
主な方法:
- ナミビアのナマ群の地質学的なフィールドワークと化石収集.
- 化石標本の詳細な形態学的および古環境的分析.
- 化石層の年齢を定めるための放射線年代測定.
主要な成果:
- ナマポイキア・リートオゲンシス (Namapoikia rietoogensis gen. et sp.) の発見について nov. 大きな (最大1メートル) バイオミネラライズされたメタゾーン.
- この生物は,複雑で頑丈な骨格を有しており,おそらくカニダリアンまたはポリフェリアンを表しています.
- ナマポイキアは,微生物のサンゴ礁内の垂直の裂け目で覆われており,特定の古環境条件を示しています.
結論:
- 生物学的に制御された鉱化を持つ大型モジュラー型メタゾアは,これまで考えられていたよりも約1500万年前に現れた.
- この発見は,プロテロゾーイク期の末期におけるメタゾウ類の進化に関する我々の理解に大きな影響を与えます.
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