期刊
PRECAMBRIAN RESEARCH
卷 173, 期 1-4, 页码 201-211出版社
ELSEVIER
DOI: 10.1016/j.precamres.2009.01.008
关键词
Proterozoic; Individuality; Complexity; Cell signaling; Cell adhesion
资金
- UCLA/IGPP Center for the Study of Evolution and the Origin of Life (CSEOL)
- NASA Astrobiology Institute
A multicellular grade of organization is widely distributed among extant organisms and widely represented in the pre-Ediacaran fossil record. A review of the pre-Ediacaran record identifies nine general categories of multicellular organization: (I) simple clonal colonies; (2) integrated coenobial colonies; (3) simple uniseriate filaments; (4) simple multiseriate filaments; (5) simple coenocytic filaments; (6) branched coenocytic filaments; (7) complex multicellular filaments; (8) complex multicellular vesicles; and (9) problematic macrofossils. A small subset of these fossils can be assigned to extant lineages based on taxonomically diagnostic patterns of cell division, including compelling evidence for chroococcacean, oscillatoriacean and pleurocapsalean cyanobacteria, bangiophycaceaen red algae and hydrodictaceaen green algae. The identification of pre-Ediacaran vaucheriaceaen xanthophyte algae and siphonocladalean green algae is almost as secure, whereas the case for early multicellular nostocalean/stigonematalean cyanobacteria and fungi requires further corroboration: a distinctively patterned acritarch is tentatively identified as an early Neoproterozoic poriferan. Despite this breadth of early multicellular experimentation, there is no evidence for organ-grade differentiation prior to the Ediacaran. Indeed, it is the absence of eumetazoans and embryophytes that distinguishes the pre-Ediacaran world from the fundamentally richer and more dynamic biosphere of the Phanerozoic. (C) 2009 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据