Staurinidia is a genus of Ediacaran soft-bodied organism from the deposits of the Ust'-Pinega formation. It is a monotypic genus, containing only the single species Staurinidia crucicula.[1] The genus was first described in 1985 by Russian palaeontologist Mikhail A. Fedonkin. S. crucicula's four-fold symmetry is present as a result of four canals radiating from the middle of a small cavity in the middle of the body.[1] Other forms with four way symmetry, mainly Medusoid forms, from the Ediacaran (Conomedusites, Persimedusites) comprise an essential chunk of the Ediacaran diversity of symmetry; their organisations are similar to, though smaller than, those of a modern-day Scyphozoan Cnidarian.[2]
| Staurinidia Temporal range:
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|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Scyphozoa |
| Family: | Incertae sedis |
| Genus: | †Staurinidia Fedonkin, 1985 |
| Species: | †S. crucicula
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| Binomial name | |
| †Staurinidia crucicula Fedonkin, 1985
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Description
editS. crucicula fossils are preserved as 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 Staurinidia ranges from 6 millimeters (0.24 in)-10 millimeters (0.39 in), the width of the radial canals is 1 millimeter (0.039 in) and the length of the marginal tentacles being 4 millimeters (0.16 in)-5 millimeters (0.20 in).[1] The canals give the animal a four-fold symmetry typical to that of other Ediacaran Cnidarians.[2] Staurinidia is regarded as one of the simplest of all Ediacaran Cnidarians that show four-way rotational axis.[3]
See also
editReferences
edit- ^ a b c d e Fedonkin, Mikhail A.; Sciences), Mikhail A. (Head Fedonkin, Laboratory of Precambrian Organisms Russian Academy of; Gehling, James G.; Museum), James G. (Senior Curator Gehling, retired 6 27 2019 South Australian; Grey, Kathleen; Narbonne, Guy M.; Vickers-Rich, Patricia; University), Patricia (Director Vickers-Rich, Monash (Mar 16, 2007). The Rise of Animals: Evolution and Diversification of the Kingdom Animalia. JHU Press. ISBN 9780801886799. Retrieved July 1, 2022 – via Google Books.
{{cite book}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link) - ^ a b Origin and Early Evolution of the Metazoa. Springer. 21 November 2013. ISBN 9781489924278.
- ^ The Vendian System: Vol. 1 Paleontology. Springer. 27 August 1990. ISBN 9783540501428.