Palaeopascichnida
Group of enigmatic agglutinating organisms
From Wikipedia, the free encyclopedia
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.
Grazhdankin & Maslov, 2009[2]
| Palaeopascichnida Temporal range: Ediacaran, | |
|---|---|
| |
| A fossil specimen of Palaeopascichnus, a palaeopascichnid which has now been recognised as a body fossil | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | incertae sedis |
| Informal group: | †Palaeopascichnida Grazhdankin & Maslov, 2009[2] |
| Genera | |
| |
Description
Palaeopascichnids are agglutinating organisms, which primarily composed of globular or sausage-shaped chambers, with occasional branches seen in a majority of specimens.[3]
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.[3] Some studies have even suggested a probably foraminiferan affinity for the palaeopascichnids.[4][5]
Distribution
Palaeopascichnids are very widespread, being found across the globe, from the East European platform (White Sea,[6] Urals,[7] Moscow syneclise, Podolia,[8] Finnmark[9]), to Siberia (Olenyok uplift, Uchur-Maya basin[10]), South China (Lantian,[11] Dengying[12] ), Australia (Flinders Ranges[13]), India (Tethys[14]), Avalonia (Charnwood,[15] Newfoundland and Labrador[16]), Romania (Histria Formation[17]), Brazil (Itajaí Basin[18]), and Oman (Fara Formation[19]).
Taxonomy
If ratified, the group would include the following genera and species:[20]
- 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