| Coeloscleritophora Temporal range: Cambrian-Ordovician
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|---|---|
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | incertae sedis |
| Class: | †Coeloscleritophora |
| Groups included | |
The Coelosclerithophorans are a polyphyletic group of organisms bearing hollow sclerites made of aragonite, and with a supposedly distinctive microstructure.[1]
Their skeletons may be homologous to those of the molluscs,[2] and Halkieria looks very much like a polyplacophoran. The shells of this group and the molluscs appear to have originated in the same fashion.[2] However, there are several reasons to doubt this relationship,[3] many of which may not pass muster.[4]
There are two groups within the coeloscleritophorans: the Sachitids, to which Halkieria and Wiwaxia belong, and the Chancellorids. The Ediacaran fossil Ausia has been touted as an ancestral 'intermediate' between both of these groups.[5]
These are common constituents of Lower Cambrian small shelly fossil assemblages.
- ^ Porter, S. M. (2008). "Skeletal Microstructure Indicates Chancelloriids and Halkieriids Are Closely Related". Palaeontology. 51 (4): 865–879. doi:10.1111/j.1475-4983.2008.00792.x.
- ^ a b Bengtson, S. (1992). "The cap-shaped Cambrian fossil Maikhanella and the relationship between coeloscleritophorans and molluscs". Lethaia. 25 (4): 401–420. doi:10.1111/j.1502-3931.1992.tb01644.x.
- ^ Yochelson, E. L. (1993). "Molluscan affinity of coeloscleritophorans". Lethaia. 26 (1): 47–48. doi:10.1111/j.1502-3931.1993.tb01509.x.
- ^ Bengtson, S. (1993). "Molluscan affinity of coeloscleritophorans — reply". Lethaia. 26 (1): 48. doi:10.1111/j.1502-3931.1993.tb01510.x.
- ^ Dzik, Jerzy (August 2009). "Possible Ediacaran Ancestry of the Halkieriids" (PDF). In Smith, Martin R.; O'Brien, Lorna J.; Caron, Jean-Bernard (eds.). Abstract Volume. International Conference on the Cambrian Explosion (Walcott 2009). Toronto, Ontario, Canada: The Burgess Shale Consortium (published 31 July 2009). ISBN 978-0-9812885-1-2.