Trace fossils accompanying possible “Ediacaran organisms” in the Middle Cambrian sediments of the St. Petersburg Region, Russia

Abstract

Shallow-marine Middle Cambrian sandy sediments of the St. Petersburg Region (i.e., sedimentary cover of the Baltic Shield) bear non-shelly, cup-like fossils, interpreted tentatively as descendants of Ediacaran organisms. The ichnoassemblage accompanying this occurrence consists of Skolithos, Diplocraterion and indeterminate biogenic sedimentary structures. The ichnofabric index is low (1-2). The probable body fossils are crosscut by the trace fossils. Though simple, the ichnoassemblage recorded here yields valuable information on the environment that could have hosted Ediacaran organisms during the earliest Phanerozoic.