Representatives of the Miaohe Biota from the Ediacaran (Vendian) Pre-Shuram Strata of the Patom Highland, Siberia

Abstract

The carbonaceous macrofossils which belong to multicellular algae and which were previously known from the younger (>570 Ma) Miaohe biota are found for the first time in the Lower Vendian (Middle Ediacaran, ~580 Ma) rocks of the Ura Formation of the Patom Basin in Siberia. The Ura macrofossils include phytoleims of unbranched ribbon-like thalli preserved on the surfaces of silty mudstones. Among the fossils, the species Liulingjitaenia alloplecta and Jiuqunaoella simplicis are identified. The features of their structure are considered. The in vivo forms of the organisms and their colonies are interpreted. It is shown that these organic macrofossils were a noticeable detritus-forming component of the Ura Basin. The Ura macrophytes coexisted with the Early Ediacaran microbiota and composed a common ecosystem of the paleobasin, which formed shortly before the Shuram event and was significantly transformed after it.