Coeloscleritophoran | ||
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Scientific classification | ||
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Included groups | ||
The Coelosclerithophorans are a polyphyletic group of organisms bearing hollow sclerites made of aragonite.
Their skeletons may be homologous to those of the molluscs,[1] and Halkieria looks very much like a polyplacophoran. The shells of this group and the molluscs appear to have originated in the same fashion.[1] However, there are several reasons to doubt this relationship,[2] many of which may not pass muster.[3]
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.[4]
These are common constituents of Lower Cambrian small shelly fossil assemblages.