Palaeopascichnida

Palaeopascichnida is a proposed group, which includes all known elongated, agglutinating organisms from the Ediacaran period. The term was first used in 2009 by Grazhdankin & Maslov.

Description

Palaeopascichnids are agglutinating organisms, which primarily composed of globular or sausage-shaped chambers, with occasional branches seen in a majority of specimens.
They were originally described as trace fossils, but further studies found this to not be the case, due to the branching of the fossils and some also being disarticulated, with chambers found separated from the rest of the body. Some studies have even suggested a probably foraminiferan affinity for the palaeopascichnids.

Distribution

Palaeopascichnids are very widespread, being found across the globe, from the East European platform, to Siberia, South China, Australia, India, Avalonia, Romania, Brazil, and Oman.

Taxonomy

If ratified, the group would include the following genera and species:

Genus Palaeopascichnus Palij, 1976
* P. delicatus Palij, 1976
* P. linearis Fedonkin, 1976
* P. gracilis Fedonkin, 1985
Genus Orbisiana Sokolov, 1976
* O. simplex Sokolov, 1976
* O. intorta Kolesnikov & Desiatkin, 2022
* O. spumea Kolesnikov & Desiatkin, 2022
Genus Curviacus Shen et al., 2017
* C. ediacaranus Shen et al., 2017