Evidences of the Oldest Trophic Interactions in the Riphean Biota (Lakhanda Lagerstätte, Southeastern Siberia)

Evidences of perforation of organic-walled fossil eukaryotes by other organisms has been found in the Lakhanda Lagerstätte (1030–1000 Ma, southeastern Siberia). The type of perforation is most similar to the type described from the Akademikerbren (750 Ma, Spitsbergen), Chuar (780–740 Ma, United States) and Shaler Supergroups (1150–900 Ma, Arctic Canada). The biogenic origin of the perforations has been substantiated. A hypothesis of perforation of fossils by zoosporic fungi found in the same deposits has been proposed. At the same time, the taxonomic diversity of eukaryotic “prey” taxa and the primitive morphology of such perforations do not allow us to qualify the perforators as distinct protists and do not point out the absolute certainty of selective predation among eukaryotes during the Riphean (Mesoproterozoic). Thus, the hypothesis of explosive diversification of eukaryotes in the Late Proterozoic driven by selective predation cannot yet be confirmed paleontologically.