Kerguelen Plateau and the Late Cretaceous southern-continent bioconnection hypothesis: tales from a topographical ocean
Kerguelen Plateau and the Late Cretaceous southern-continent bioconnection hypothesis: tales from a topographical ocean
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DOI：
10.1111/j.1365-2699.2009.02105.x
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发表时间：
2009-09-01
影响因子：
3.9
通讯作者：
Aitchison, Jonathan C.
中科院分区：
文献类型：
--
作者：
Ali, Jason R.;Aitchison, Jonathan C.
目的严格评估一个有影响力的古生物地理假说，该假说认为在晚白垩世(直到约80 Ma)，科尔盖伦高原在南极洲东部和印度之间提供了一条陆路堤道，进而形成了南美洲和马达加斯加之间更长的陆上路线的一部分。此外，高原的西北端和东南端并不直接与印度和南极洲毗邻，而是被巨大的缺口隔开。因此，当时认为这两个大陆是由一条贯穿整个大厦的陆路连接起来的想法几乎肯定是错误的。主要结论目前可用的实物证据表明，完全基于生物数据的晚白垩世南部大陆连接假说是站不住脚的。假设马达加斯加-印度的化石和/或现存的生物记录与南美洲的化石和/或现存生物记录密切相关，则需要探索替代的古地理情景来解释这个难题。应考虑水上扩散和(或)替代航道，包括一条更直接的非洲路线(横渡莫桑比克海峡和当时略窄的中大西洋)。
AimTo evaluate rigorously an influential palaeobiogeographical hypothesis which states that in the Late Cretaceous (until c. 80 Ma) the Kerguelen Plateau provided a terrestrial causeway between East Antarctica and India that, in turn, formed part of a longer overland route between South America and Madagascar.LocationSouthern Ocean, Indian Ocean, East Antarctica, India and Madagascar.MethodsPalaeogeographical modelling drawing on geological and geophysical data, bathymetric charts and plate tectonic reconstructions.ResultsDuring the Late Cretaceous, only small portions of the present-day Kerguelen Plateau were sub-aerial. Additionally, the plateau's north-north-west and south-south-east ends did not directly abut India and Antarctica, but instead were separated by large gaps. Thus, the notion that the two continents were then linked by a land route running the entire length of the edifice is almost certainly incorrect.Main conclusionsThe currently available physical evidence indicates that the Late Cretaceous southern-continent connection hypothesis, which is based exclusively on biological data, is untenable. Assuming the fossil and/or extant biological records of Madagascar-India are closely related to those of South America, alternative palaeogeographical scenarios need to be explored to explain this conundrum. Overwater dispersal and/or an alternative passage involving a more direct route via Africa (with crossings of the Mozambique Channel and a then appreciably narrower Central Atlantic) should be considered.