Revised age estimates for the later Paleogene mammal faunas of Egypt and Oman
Revised age estimates for the later Paleogene mammal faunas of Egypt and Oman
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DOI：
10.1073/pnas.0600689103
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发表时间：
2006-03-28
影响因子：
11.1
通讯作者：
Seiffert, ER
中科院分区：
文献类型：
--
作者：
Seiffert, ER
埃及北部的Jebel Qatrani组产生了非洲-阿拉伯关于古近纪哺乳动物进化的主要记录，包括世界上最完整的早期类人灵长类动物遗骸。最近对Fayum哺乳动物的研究认为，Jebel Qatrani组包含一个重要的始新世成分(约340米中的150个)，该序列中的大多数类群年龄在3540万至3330万年之间，即始新世最晚至渐新世最早。对埃及和阿曼(多法省塔卡和塔伊蒂尼提地区)出露的古近纪晚期地层的年代学证据的重新分析表明，这一假说不再成立。修正的Fayum和DhoFar磁性地层学对比表明：(I)只有Jebel Qatrani组最低的48m可能是始新世；(H)最年轻的Fayum类人，包括众所周知的物种，如Aegyptopithecus zeuxis和Apidium phiomense，可能在30.2-29.5 Ma之间，大约比先前认为的年轻3-4 Ma；(Iii)少化石类人并没有在始新世-渐新世界线上灭绝，而是至少又持续了2.5 Ma；(Iv)Ppliopithecid类人最早出现在Fayum地区，大约在31.5 Ma，在始新世-渐新世界线之后很久；(V)最年轻的法尤姆哺乳动物可能只比来自埃塞俄比亚奇尔加的28-27 Ma的哺乳动物年长约1 Ma，而不是之前认为的4-5 Ma。无论渐新世非洲-阿拉伯哺乳动物进化记录中存在的差距，现在主要局限于最新一次渐新世采样较差的27-23 Ma窗口。
The Jebel Qatrani Formation of northern Egypt has produced Afro-Arabia's primary record of Paleogene mammalian evolution, including the world's most complete remains of early anthropoid primates. Recent studies of Fayum mammals have assumed that the Jebel Qatrani Formation contains a significant Eocene component (approximate to 150 of 340 m), and that most taxa from that succession are between 35.4 and 33.3 million years old (Ma), i.e., latest Eocene to earliest Oligocene in age. Reanalysis of the chronological evidence shared by later Paleogene strata exposed in Egypt and Oman (Taqah and Thaytiniti areas, Dhofar Province) reveals that this hypothesis is no longer tenable. Revised correlation of the Fayum and Dhofar magnetostratigraphies indicates that (i) only the lowest 48 m of the Jebel Qatrani Formation are likely to be Eocene in age; (h) the youngest Fayum anthropoids, including well known species such as Aegyptopithecus zeuxis and Apidium phiomense, are probably between 30.2 and 29.5 Ma, approximate to 3-4 Ma younger than previously thought; (iii) oligopithecid anthropoids did not go extinct at the Eocene-Oligocene boundary but rather persisted for at least another 2.5 Ma; (iv) propliopithecid anthropoids first appear in the Fayum area at approximate to 31.5 Ma, long after the Eocene-Oligocene boundary; and (v) the youngest Fayum mammals may be only approximate to 1 Ma older than the 28- to 27-Ma mammals from Chilga, Ethiopia, and not 4-5 Ma older, as previously thought. Whatever gap exists in the Oligocene record of Afro-Arabian mammal evolution is now limited primarily to a poorly sampled 27- to 23-Ma window in the latest Oligocene.