[1] The Ordovician scleritome-bearing Curviconophorus,[8] as well as the Halwaxiids, lobopods and echinoderms, demonstrate the diversity of organisms which may produce a scleritome of this nature.

[7] The related Campitius was originally suggested to be part of a radula rather than a scleritome,[9] but is now considered a synonym of Volborthella.

[3] Volborthella is widespread, and a useful biostratigraphic indicator;[7] it has been found in North America, Greenland, Spitsbergen, and northeastern Europe, and is restricted to Lower Cambrian rocks, appearing before the trilobites and co-existing with them for some time.

[1] Volborthella has been described as a 'failed attempt in mineralisation'; it constructed its wall by agglutinating grains of sediment, much like some foramanifera, and declined in conjunction with the origin of truly-biomineralising organisms.

Some Volborthella specimens do show taphonomic hints that some form of lightly mineralised sheath may have enclosed its agglutinated shell.