氨类动物的形态差异和珀姆纪大规模灭绝的标志
1Centre de Sédimentologie-Paléontologie, FRE CNRS 2761, Université de Provence, 3 place Victor-Hugo, F-13331 Marseille Cedex 3, France. lvillier@up.univ-mrs.fr
Science (New York, N.Y.)
|October 9, 2004
概括
珀米纪时期的氨类物种灭绝模式是复杂的. 形态差异分析揭示了边界前的衰退和随机的波斯末期大灭绝,这表明了灾难性的原因.
科学领域:
- 古生物学的古生物学
- 进化生物学 进化生物学
- 在平流图学中,平流图学.
背景情况:
- 珀米纪化石记录,特别是类动物的化石记录,在分类学上有偏见,限制了对灭绝事件的理解.
- 形态差异,或贝形状的多样性,提供了更强大的灭绝选择性的衡量标准.
- 之前的研究强调了米-三叠纪边界作为一个主要的灭绝事件的重要性.
研究的目的:
- 通过使用形态差异来研究在波斯纪期间的类动物灭绝模式.
- 测试关于灭绝事件选择性的假设,包括背景和灾难性原因.
- 为了提供一个更完整的图片的米亚 ammonoid 多样性超出分类学计数.
主要方法:
- 分析氨体外形状的变化,以量化形态差异.
- 对大约3000万年间的差异趋势的检查,导致米-三叠纪边界.
- 在卡普塔尼亚危机期间的灭绝模式和末珀米亚大量灭绝的比较.
主要成果:
- 在二叠纪-三叠纪边界之前的3000万年里,观察到一个显著的趋势,即减少了氨体的形态差异.
- 卡普塔尼亚危机表现出选择性灭绝模式,与背景环境变化一致.
- 珀米纪末期的大规模灭绝表明了随机的,非选择性的氨基体形态的分类.
结论:
- 单独的分类学多样性不足以理解由于化石记录偏差而导致的珀米亚 ammonoid 灭绝.
- 形态差异分析揭示了不同的灭绝模式,将背景与灾难性事件区分开来.
- 波斯末期大规模灭绝的非选择性性质支持了灾难性的原因,与选择性的卡普坦危机形成鲜明对比.
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