Palaeopascichnus is an unusual fossil found in shallow marine depositional environments worldwide during the latest Ediacaran Period. It is composed of a series of progressively expanding 'sausage-shaped' units, which often branch after reaching a certain size.
It has been variously interpreted as a trace fossil (Palij, 1976), a bedding-parallel stromatolite (Runnegar, 1995), a brown alga (Haines, 2000) and a giant protozoan (Seilacher et al., 2003). A recent paper assessing the growth and development in Palaeopascichnus arguably described it as a body fossil of a protozoan organism (Antcliffe et al., 2011).
Flinders Ranges, South Australia
Khorbusuonka River, Siberia, Russia
Jensen et al., 2003
Seilacher et al., 2003
Antcliffe et al., 2011
Palij, V.M., Posti, E. & Fedonkin, M.A., 1979. Soft-bodied Metazoa and trace fossils of Vendian and Lower Cambrian. In Upper Precambrian and Cambrian Paleontology of East-European Platform. Keller, B.M. & Rozanov, A.Yu., eds, Moscow, Nauka, 49-82.