Staurinidia

Stauridinia is a genus of Ediacaran soft-bodied organism from the deposits of the Ust'-Pinega formation. It contains a single species, S. crucicula.^[1] The genus was first described in 1985 by Russian palaeontologist Mikhail A. Fedonkin. S. crucicula possess four-fold symmetry as a result of four radial canals radiating from the middle of a small cavity in the middle of the body.^[1] Other forms with four way symmetry from the Ediacaran (Conomedusites, Persimedusites) comprise an essential block of the Ediacaran diversity of symmetry; their organisations are of typical to that of a modern-day Scyphozoan Cnidarian although much smaller compared to them.^[2]

S. crucicula fossils preserve a small discoidal form baring four radial canals emitting from the fossils centre in which a small cavity is present. The ends of the canals are often swollen when pointing towards the organisms periphery.^[1] In very rare instances, tentacles are present and preserved around the outside of the disc's margin. The margins of the disc are very thin with there being no indication of an encircling ridge or canal.^[1] Rather deep impressions are preserved of Staurinidia suggesting that the animal would've had significant relief.

The diameter of the body of Stauridinia ranges from 6 millimeters (0.24 in) to 10 millimeters (0.39 in), the minimum width of the radial canals is 1 millimeter (0.039 in) and the length of the marginal tentacles being 4 millimeters (0.16 in) to 5 millimeters (0.20 in).^[1] The canals radiating from the centre of the body give the animal a four-fold symmetry typical to that of other Ediacaran Cnidarians.^[2] Stauridinia is regarded as one of the simplest of all Ediacaran Cnidarians that show a rotational axis and radial symmetry.^[3]

• List of Ediacaran genera