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DOI	10.1016/j.palaeo.2018.11.009
	Resolution of the earliest metazoan record: Differential taphonomy of Ediacaran and Paleozoic fossil molds and casts
	MacGabhann B.A.; Schiffbauer J.D.; Hagadorn J.W.; Van Roy P.; Lynch E.P.; Morrison L.; Murray J.
发表日期	2019
ISSN	0031-0182
起始页码	146
结束页码	165
卷号	513
英文摘要	Much of our knowledge of early metazoan evolution is derived from unmineralized death mask or endorelief mold and cast fossils in Ediacaran clastic sedimentary rocks. This record is often regarded as a unique ‘Ediacaran taphonomic window’; however, the prevalence of soft-bodied molds and casts in Paleozoic clastic rocks has been increasing, begging an extension, or modification, to our understanding of this preservational motif. Chief amongst such fossils are eldonids, a non-biomineralized group of stem deuterostomes. Because eldonids are also preserved as compressed or flattened fossils from deposits like the Burgess Shale, Chengjiang and Kaili, they offer a comparative case study for evaluating the taphonomic fidelity of mold/cast-style preservation during this interval. EDS and Raman microspectroscopic analysis of Ordovician and Devonian eldonid molds and casts, and comparison with Burgess Shale eldonids, suggests the mold/cast taphonomic style produces significantly lower fidelity of fossil preservation. We propose that eldonid mold/cast fossils are preserved by the adsorption of reduced iron ions onto tissues composed primarily of high molecular weight (HMW) biopolymers which require enzymatic degradation prior to decay. Nucleation and growth of aluminosilicates and/or sulfides around these adsorbed ions forms a fossilizable surface veneer, preserving a death mask mold. More labile tissues could not be fossilized in this mold and cast style. Ediacaran mold and cast fossils from South Australia, the White Sea region of Russia, Namibia, and Newfoundland exhibit preservational characteristics consistent with this new proposed model. Analysis of their preservational mode suggests that the first metazoans, which would have lacked HMW biopolymeric tissues, could not have been fossilized in this particular style. Thus, understanding the origin and earliest evolution of the Metazoa requires a focus on alternative modes of fossilization. © 2018 Elsevier B.V.
英文关键词	Adsorption; Aluminosilicification; Biopolymers; Eldonid; Pyritization; Taphonomy
语种	英语
scopus关键词	adsorption; Devonian; Ediacaran; evolution; fossil record; growth; invertebrate; metazoan; Ordovician; Paleozoic; sedimentary rock; shale; taphonomy; Arctic Ocean; Australia; Canada; Chengjiang; China; Namibia; Newfoundland; Newfoundland and Labrador; Russian Federation; South Australia; White Sea; Yunnan; Deuterostomia; Metazoa
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151200
作者单位	Earth and Ocean Sciences, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, H91 TK33, Ireland; Department of Geography, Mary Immaculate College, University of Limerick, South Circular Road, Limerick, V94 VN26, Ireland; Department of Geological Sciences, University of Missouri, 101 Geology Building, Columbia, MO 65211, United States; X-ray Microanalysis Core Facility, University of Missouri, 101 Geology Building, Columbia, MO 65211, United States; Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, United States; Department of Geology and Soil Science, Ghent University, Krijgslaan 281/S8, Ghent, B-9000, Belgium; Geological Survey of Sweden, Box 670, Uppsala, 751 28, Sweden; Irish Centre for Research in Applied Geosciences (iCRAG), Ireland
推荐引用方式 GB/T 7714	MacGabhann B.A.,Schiffbauer J.D.,Hagadorn J.W.,et al. Resolution of the earliest metazoan record: Differential taphonomy of Ediacaran and Paleozoic fossil molds and casts[J],2019,513.
APA	MacGabhann B.A..,Schiffbauer J.D..,Hagadorn J.W..,Van Roy P..,Lynch E.P..,...&Murray J..(2019).Resolution of the earliest metazoan record: Differential taphonomy of Ediacaran and Paleozoic fossil molds and casts.Palaeogeography, Palaeoclimatology, Palaeoecology,513.
MLA	MacGabhann B.A.,et al."Resolution of the earliest metazoan record: Differential taphonomy of Ediacaran and Paleozoic fossil molds and casts".Palaeogeography, Palaeoclimatology, Palaeoecology 513(2019).