東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Contributions to the paleobiology of...

Xiao, Shuhai.

FindBook

Google Book

Amazon

博客來

Contributions to the paleobiology of proterozoic eukaryote evolution.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Contributions to the paleobiology of proterozoic eukaryote evolution./
作者:	Xiao, Shuhai.
面頁冊數:	235 p.
附註:	Source: Dissertation Abstracts International, Volume: 59-05, Section: B, page: 2090.
Contained By:	Dissertation Abstracts International59-05B.
標題:	Paleontology. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=9832311
ISBN:	9780591854015

Contributions to the paleobiology of proterozoic eukaryote evolution.
Xiao, Shuhai.

Contributions to the paleobiology of proterozoic eukaryote evolution. - 235 p.

Source: Dissertation Abstracts International, Volume: 59-05, Section: B, page: 2090.

Thesis (Ph.D.)--Harvard University, 1998.

On the southern margin of the North China Platform, supposedly Neoproterozoic (1000 $\sim$ 544 Ma old) successions contain a unique microfloral assemblage of large (ca. 100 $\mu$m in diameter) acanthomorphic acritarchs (single-celled eukaryotes). Integrative stratigraphic analysis and correlation using petrofabrics, radiometric and carbon isotopic data, however, suggest that these "Neoproterozoic" successions are in fact Mesoproterozoic (1600 $\sim$ 1000 Ma old) in age. This new age assignment implies that morphological diversification of protists inferred from molecular phylogenies may have accelerated in the Neoproterozoic Era but began earlier.

ISBN: 9780591854015Subjects--Topical Terms:

518862
Paleontology.

Contributions to the paleobiology of proterozoic eukaryote evolution.
LDR:04257nmm a2200337 4500 001 2067134
005 20160226101809.5
008 170521s1998 ||||||||||||||||| ||eng d
020 $a 9780591854015
035 $a (MiAaPQ)AAI9832311
035 $a AAI9832311
040 $a MiAaPQ $c MiAaPQ
100 1 $a Xiao, Shuhai. $3 3181989
245 1 0 $a Contributions to the paleobiology of proterozoic eukaryote evolution.
300 $a 235 p.
500 $a Source: Dissertation Abstracts International, Volume: 59-05, Section: B, page: 2090.
500 $a Adviser: Andrew H. Knoll.
502 $a Thesis (Ph.D.)--Harvard University, 1998.
520 $a On the southern margin of the North China Platform, supposedly Neoproterozoic (1000 $\sim$ 544 Ma old) successions contain a unique microfloral assemblage of large (ca. 100 $\mu$m in diameter) acanthomorphic acritarchs (single-celled eukaryotes). Integrative stratigraphic analysis and correlation using petrofabrics, radiometric and carbon isotopic data, however, suggest that these "Neoproterozoic" successions are in fact Mesoproterozoic (1600 $\sim$ 1000 Ma old) in age. This new age assignment implies that morphological diversification of protists inferred from molecular phylogenies may have accelerated in the Neoproterozoic Era but began earlier.
520 $a In South China, the Neoproterozoic Doushantuo Formation (570 $\pm$ 20 Ma old) contains two Lagerstatten, a carbonaceous compression assemblage in Miaohe near the Yangtze Gorges and a cellularly preserved biota in Weng'an, Guizhou Province. Miaohephyton bifurcatum from the Miaohe biota preserves parenchymatous cellular structures, apical and intercalary growth patterns, abscission and reproductive structures. In combination these features suggest that Miaohephyton bifurcatum is a phaeophyte, possibly a fucalean. This interpretation indicates that the secondary endosymbiotic event that gave rise to the photosynthetic stramenopiles must have occurred before 570 $\pm$ 20 Ma. In addition, along with other fossils, Miaohephyton bifurcatum implies that the major algal clades not only diverged, but also independently achieved multicellularity during the Neoproterozoic Era.
520 $a Doushantuo phosphorites in Weng'an preserve both algal thalli and animal embryos in cellular detail. Globular microfossils previously interpreted as colonial algae are here reinterpreted as equally cleaving, holoblastic animal blastulas; their cleavage geometry, constant size at different cleavage stages, and enclosing envelopes all support an embryo interpretation. It is as yet uncertain whether and how these embryos might have developed into adults. Regardless, these embryos are thought to have had a non-planktotrophic developmental mode because of their relatively large egg size. This and other paleontological evidence implies the antiquity of non-planktotrophy.
520 $a Doushantuo embryo fossils also point to a bright future of searching for well preserved micrometazoans in older phosphatic nodules. To understand where and how to look for phosphatized fossils in older rocks, a more complete understanding of phosphatization is necessary. Through SEM examination, it has been demonstrated that phosphatic encrustation and impregnation are the principal processes involved in the phosphatization of Doushantuo soft tissues. In addition, the preservation style of animal embryos is different from that of algal thalli; the phosphatization of animal soft tissues may be facilitated by infesting bacteria.
520 $a The Mesoproterozoic large acanthomorphic acritarchs and Doushantuo embryo fossils do not minimize the magnitude and importance of major eukaryotic diversification in the Neoproterozoic Era and metazoan diversification during the Cambrian Explosion. Instead, they suggest that both eukaryotes and metazoans may have a protracted prehistory before their respective explosive radiations, a pattern that has long been recognized in the fossil record of other groups.
590 $a School code: 0084.
650 4 $a Paleontology. $3 518862
650 4 $a Paleobotany. $3 545182
690 $a 0418
690 $a 0345
690 $a 0985
710 2 $a Harvard University. $3 528741
773 0 $t Dissertation Abstracts International $g 59-05B.
790 $a 0084
791 $a Ph.D.
792 $a 1998
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=9832311