Chemical Composition of Paleozoic and Mesozoic Fossil Invertebrate Cuticles As Revealed by Pyrolysis-Gas Chromatography/Mass Spectrometry

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• 作者：B. Artur Stankiewicz ; Derek E. G. Briggs ; and Richard P. Evershed
• 刊名：Energy & Fuels
• 出版年：1997
• 出版时间：May 1997
• 年：1997
• 卷：11
• 期：3
• 页码：515 - 521
• 全文大小：184K
• 年卷期：v.11,no.3(May 1997)
• ISSN：1520-5029

文摘

The cuticles of 15 fossil invertebrates ranging in age from Silurian toCretaceous, and includingboth marine and terrestrial organisms, have been analyzed usingpyrolysis-gas chromatography/mass spectrometry (py-GC/MS). Modern invertebrate cuticles wereanalyzed in the same wayas a basis for comparison. The modern cuticles yielded pyrolysisproducts derived from chitinand proteins, but none of these components was detected in thepyrolysates of the fossil cuticles.The fossil cuticles fall into two, chemically distinct groups:aliphatic, yielding pairs of n-alk-1-enes and n-alkanes upon pyrolysis, and aromatic,producing pyrolysates dominated by alkylbenzenes and alkylindenes. Aliphatic pyrolysates may derive throughpolymerization of lipids,e.g., epicuticular waxes, during diagenesis. Alternatively thealiphatic moieties found in algae(algaenan) or in plants (e.g., cutan, suberan) may have beenincorporated into the animal cuticlesby unknown diagenetic processes. Alkylindenes are major pyrolysisproducts of the fossil cuticlesthat generate predominantly aromatic components. This associationmay resolve the enigma ofthe frequent occurrence of alkylindenes as minor components in thepyrolysates of most types ofkerogen. The abundant thiophenes in the same pyrolysates mayreflect sulfur incorporationduring diagenesis of the original amino sugar (glucosamine) moietiesthat comprise the chitinbiopolymer.