概括
化石的水母类生物Dipleurozoa在北美被发现,扩大了它们已知的范围. 这些化石表明,这种类存在于从坎布里亚下到下西卢里亚时期.
科学领域:
- 古生物学的古生物学
- 进化生物学 进化生物学
- 海洋生物学 海洋生物学
背景情况:
- 以前在澳大利亚发现了表现出双边对称性的Coelenterata的化石遗骸.
- 这些独特的化石被哈林顿和摩尔分类为一个新的类别,Dipleurozoa.
- 此前,Dipleurozoa类在澳大利亚以外尚未报告.
研究的目的:
- 为了描述从Shawangunk (Tuscarora) 形成中新发现的Dipleurozoa标本.
- 为了确定Dipleurozoa类的分层和地理范围.
- 在Dipleurozoa类中建立新的物种和新属.
主要方法:
- 古生物学挖掘和对化石遗骸的分析.
- 石层学分析以确定含有化石的岩层的年龄.
- 基于物理特征识别新的物种和属的比较形态学.
主要成果:
- 最近,许多Dipleurozoa标本在宾夕法尼亚州德拉华水沟的Shawangunk (Tuscarora) 形成中被发现.
- 已经确定了三种属于Dipleurozoa新属的新物种.
- 这些发现表明Dipleurozoa化石的范围从布里亚下到下布里亚层.
结论:
- 类Dipleurozoa的地理分布比以前知道的更广泛,延伸到北美东部.
- 证实了Dipleurozoa的平分层范围从坎布里亚下期延伸到至少下级的西卢里亚.
- 这一发现显著提高了我们对早期海洋无脊椎动物进化和古生物学地理学的理解.
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