Stenothecoida
| Stenothecoida Temporal range: Early–mid-Cambrian,
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|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Superphylum: | Lophotrochozoa |
| Class: | †Stenothecoida Yochelson, 1968 |
Stenothecoida are bivalved fossils from the Early Cambrian period.
Affinity
Their affinity is uncertain. They were considered by E. L. Yochelson 1968[citation needed] to belong to Mollusca, whereas Runnegar and Pojeta (1974) suggested that they might be 'bivalved monoplacophorans'. This said, the morphology of the shell does not resemble the shell of any other class of molluscs; they also look a little like brachiopods[1] It's not clear whether their two valves are each others' mirror images, as in bivalve molluscs, though they aren't identical to one another [?].[1] It's more likely that the valves each have a single plane of symmetry (as in brachiopods), suggesting a brachiopod affiliation.[1]
As with many other Cambrian taxa,[3][4] it has been suggested that they arise through reduction of a Halkieria-like ancestor.[1]
Occurrence
The earliest occurrence dates to 525 Ma.[2]
These fossil shells have been found in Canada, China, Greenland, Kazakhstan, Kyrgyzstan, and the USA.
References
- ^ a b c d e https://www.researchgate.net/profile/Artem_Kouchinsky/publication/264808572_Molluscs_hyoliths_stenothecoids_and_coeloscleritiphorans/links/53f1ee860cf2bc0c40e6eed7.pdf.
{{cite journal}}: Cite journal requires|journal=(help); Missing or empty|title=(help) - ^ a b Kouchinsky, A. V., Bengtson, S., Runnegar, B.N., Skovsted, C.B., Steiner, M., and Vendrasco, M.J. (2012). Chronology of early Cambrian biomineralization. Geol. Mag. 149, 221–251.
- ^ 1. Cohen, B.L., Holmer, L.E., and Lüter, C. (2003). The brachiopod fold: a neglected body plan hypothesis. Palaeontology 46, 59–65.
- ^ 1. Skovsted, C.B., Betts, M.J., Topper, T.P., and Brock, G.A. (2015). The early Cambrian tommotiid genus ~Dailyatia~ from South Australia. Mem. Assoc. Australas. Palaeontol. 48, 1–117.
- Start of article at Springer Reference
- Paleobiology Database info on this class
- Abstract of a Yochelson 2007 article on the proposed class
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