Significance of "Tethyan" Fossils in the American Cordillera
Significance of "Tethyan" Fossils in the American Cordillera
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DOI：
10.1126/science.242.4877.385
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发表时间：
1988-10
期刊：
影响因子：
56.9
通讯作者：
C. R. Newton
中科院分区：
文献类型：
--
作者：
C. R. Newton
从西欧延伸到东南亚的古代特提斯水道的赤道动物群包括化石记录中最多样化的海洋类群。长期以来，在远离特提斯海道的南北美洲科迪勒拉山脉的古生代和中生代岩石中发现的类似或相同的特提斯物种一直被认为是一个主要的地理异常。两个主要的理论来解释这些异常的“特提斯”动物群在科迪勒拉的发生是，他们被长距离的构造块（怀疑是起源于特提斯附近的化石）向东迁移，或者他们通过未被发现的海洋走廊向西迁移，穿过泛大陆地区。另一种模式是，这些“特提斯”动物群是泛热带物种，扩展到东部原太平洋的衰减dilemma。这个泛热带模型可以更好地解释许多古生代和中生代早期的“特提斯”物种在美洲科迪勒拉的分布格局，并提供了一个稳定的状态假设，对其他模型可以进行测试。前白垩纪“特提斯”动物群的分布与已知的许多白垩纪和新生代热带生物群的泛热带分布相似。在新生代，类群是最多样化的特提斯和印度-西太平洋地区，但衰减的多样性扩展到赤道太平洋的许多地方，包括北美和南美的西海岸。许多印度-西太平洋物种在东太平洋的出现为美洲科迪勒拉山脉中许多异常的特提斯化石的出现提供了现代的类比。
Equatorial faunas of the ancient Tethyan seaway, which extended from western Europe to southeastern Asia, comprise some of the most diverse marine taxa in the fossil record. Comparable or identical "Tethyan" species that occur far from the Tethyan seaway in Paleozoic and Mesozoic rocks of the North and South American Cordillera have long been considered as a major biogeographic anomaly. Two leading theories to account for the occurrence of these anomalous "Tethyan" faunas in the Cordillera are that they were transported long distances to the east on tectonic blocks(suspect terranes that originated near the Tethys) or that they migrated westward via undiscovered marine corridors through continental areas of Pangea. An alternative model is that these "Tethyan" fauna were pantropic species that extended with attenuated diversities into the eastern proto-Pacific Ocean. This pantropic model can better account for the distribution patterns of many Paleozoic and early Mesozoic "Tethyan" species in the American Cordillera and provides a steady state hypothesis against which the other models can be tested. The distribution of pre-Cretaceous "Tethyan" faunas is similar to the known pantropic distribution of many Cretaceous and Cenozoic tropical biotas. During the Cenozoic, taxa were most diverse in the Tethys and Indo-West Pacific regions but extended with attenuated diversity to many parts of the equatorial Pacific Ocean, including the west coasts of North and South America. The eastern Pacific occurrence of many Indo-West Pacific species provides a modern analog for the occurrence of many anomalous "Tethyan" fossils in the American Cordillera.