Biomarkers in the Precambrian: Earth’s Ancient Sedimentary Record

The hydrocarbon remnants of biologically diagnostic lipids inform our understanding of Earth’s early ecosystems, particularly where morpho- logical vestiges of biology are absent or ambiguous. Yet both the analysis and interpretation of ancient biomarkers require scrutinous approaches. Here, we describe the status quo of Precambrian biomarker geochemistry with four examples that highlight current challenges and opportunities.