| Orbisiana Temporal range: Ediacaran | |
|---|---|
| Scientific classification | |
| Domain: | Incertae sedis |
| Genus: | † Orbisiana Sokolov, 1976 |
| Species | |
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Orbisiana is an Ediacaran benthic organism formed out of series of agglutinated spherical or hemispherical chambers. It is believed to be a close relative of Palaeopascichnus .[ citation needed ]
Orbisiana occur in aggregates made up of rows arranged in sometimes branching chains. [1] 3-D analysis has shown Orbisiana to be cylindrical in shape and open at both the top and bottom ends of its structure. [2] The chains often varied in shape from straight to curved and disorganized lines of spheres with no fixed number of spheres per chain. [2] Specimens range in size but generally have diameters of 0.2–0.9 millimetres (0.0079–0.0354 in). [3] The cell membranes of the organism are often pyritized. [4] The individual chambers are agglutinating. [5]
Two species have been documented, O. linearis and O.simplex. [2] [3] [4] [6] [7]
It fits into the palaeopascichnids, the other genus being Palaeopascichnus itself. [8]
Over 100 specimens have been collected from the lower Ediacaran Lantian Formation located in Xiuning and Yixian counties of the Anhui Province, China. [2] [7]
Orbisiana was first described by B.S. Sokolov in 1976, found in the Neoproterozoic of Russia. [3] [6]
Orbisiana likely favored calm and well aerated shallow marine habitats in which it could utilize sunlight for benthic photosynthesis. [6]