旧世界猿と類人猿のオリゴセンの分岐に関する古生物学的な証拠
Nancy J Stevens1, Erik R Seiffert, Patrick M O'Connor
1Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA. stevensn@ohio.edu
Nature
|May 17, 2013
まとめ
最古の化石類人猿と旧世界類人猿は,2520万年前のもので,タンザニアで発見された. これらの重要な化石の発見は,初期のカタリン種の進化と霊長類の歴史における重要なギャップを埋める.
科学分野:
- パレオントロジー・パレオントロジー
- 霊長類の進化について
- アフリカの古生態学
背景:
- アフリカにおける類人猿と旧世界の類人猿の初期の進化史は,ほとんど理解されていない.
- 2千万年以上前のクラウンカタリーンの化石の証拠は稀で,分子分岐の推定値とは対照的です.
- これは,Cercopithecoidea (旧世界の類人猿) と Hominoidea (類人猿) の両方の長い"幽霊系"の仮説につながりました.
研究 の 目的:
- 最も古い既知の化石類人猿と,旧世界類人猿類の最も古い幹部を記述するために.
- カタリーンの化石記録をオリゴセーン時代まで延長する.
- カタリンの多様化とオリゴセーン時代のアフリカの景観の変化との潜在的な関連を調査する.
主な方法:
- 化石化した霊長類の遺骸の古生物学的な発掘と分析.
- 化石を含む層の正確な放射線年代測定.
- 比較歯の形質分析により,歯科遺伝子の配置を決定する.
主要な成果:
- 最古の化石類人猿の発見,部分的な下と"nyanzapithecine"幹ホミノイドの特徴.
- 旧世界猿の最も古い幹の発見,下部第3歯茎.
- この2つの化石は,タンザニアのルクワ・リフト (Rukwa Rift) にある2520万年前の化石と正確に年代付けされています.
結論:
- これらの発見は,類人猿と旧世界猿の化石記録をオリゴセーンへと後押ししている.
- この発見は,カタリンの多様化が東アフリカ・リフト・システムにおける地質学的な活動と景観の変化と関連している可能性があることを示唆している.
- 化石は,アフリカにおける霊長類の初期の進化を理解するための重要な新しいデータを提供します.
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