Molecular fossils within bitumens and kerogens from the ~ 1 Ga Lakhanda Lagerstätte (Siberia, Russia) and their significance for understanding early eukaryote evolution

• DOI: 10.1007/s12542-021-00593-4
• Publication Date: 2021-12-08T18:15:27Z
• Authors: Jan-Peter Duda; Hannah König; Manuel Reinhardt; Julia Shuvalova; Pavel Parkhaev
• Keywords: Sterane; Geologic record; Taphonomy; Lagerstätte; Sedimentary organic matter; Organic geochemistry

Abstract The emergence and diversification of eukaryotes during the Proterozoic is one most fundamental evolutionary developments in Earth’s history. ca. 1-billion-year-old Lakhanda Lagerstätte (Siberia, Russia) contains a wealth eukaryotic body fossils offers an important glimpse into their ecosystem. Seeking to complement paleontological record this remarkable lagerstätte, we here explored information encoded within sedimentary organic matter (total carbon = 0.01–1.27 wt.%). Major emphasis was placed on hydrocarbons preserved bitumens kerogens, including molecular (or biomarkers) that are specific bacteria (i.e. hopanes regular steranes, respectively). Programmed pyrolysis geochemistry suggest analyzed samples about peak oil window maturity thus sufficiently well for detailed fossil studies include steranes. Together with petrographic evidence as compositional similarities corresponding consistency different independent parameters establishes indigenous syngenetic host rock. possible presence trace amounts absence steranes retain both types compounds evidences environment dominated by anaerobic no or very little inputs eukaryotes. In concert Lagerstätte, our study adds view were present but not significant Mesoproterozoic ecosystems.