カンブリア紀より4千万~5千万年前の小さな二国間化石
Jun-Yuan Chen1, David J Bottjer, Paola Oliveri
1Nanjing Institute of Geology and Paleontology, Nanjing 210008, China. chenjunyuan@163.net
まとめ
中国で双方の特徴を持つ古代動物であるVernanimalcula guizhouenaの化石が発見されました. この発見は,ビラテリアがカンブリア期以前に発生したという最古の証拠を提供します.
科学分野:
- パレオントロジー・パレオントロジー
- 発達生物学 発達生物学について
- 進化生物学の進化生物学について
背景:
- 双方向対称性の動物であるバイラテリアの起源は,進化生物学における重要な問題である.
- 系統遺伝学的研究によると,バイラテリアはカンブリア爆発より前に出現したことを示唆している.
研究 の 目的:
- 新たに発見された化石動物,Vernanimalcula guizhouenaを記述するために,ドウシャントゥー形成から.
- ビラテリアの初期の進化の化石の証拠を提供するために.
主な方法:
- 中国,ドゥシャントゥー形成の10個のリン酸化微生物化石の分析.
- 化石の断片を顕微鏡で調べ,内部と外部の構造を明らかにする.
主要な成果:
- 特定されたVernanimalcula guizhouenaは,明確な双方向的な特徴を持つ小さな動物 (<180マイクロメートル).
- 観察された特徴には,ペア化されたコエラム,潜在的感覚器官,双方向組織,腹腔口,三重芽細胞構造が含まれています.
- 複雑さは,成体形態を示唆し,幼虫段階ではない.
結論:
- Vernanimalcula guizhouenaの化石は,カンブリア期以前にバイラテリアが存在していたことを確認しています.
- この発見は,二国間の動物の初期の起源の仮説を裏付けている.
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