''Allonnia'' is a genus of

coeloscleritophoran The Coelosclerithophorans are a polyphyletic group of organisms bearing hollow sclerites made of aragonite, and with a supposedly distinctive microstructure. Their skeletons may be homologous to those of the molluscs, and ''Halkieria'' looks very ...

known as complete scleritomes from the Middle Cambrian

Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest foss ...

. It is also a constituent of the

small shelly fauna The small shelly fauna, small shelly fossils (SSF), or early skeletal fossils (ESF) are mineralized fossils, many only a few millimetres long, with a nearly continuous record from the latest stages of the Ediacaran to the end of the Early Cambri ...

. Its earliest occurrence in Yunnan dates to the Upper Meishucunian (~ Tommotian / Cambrian Stage 2) Kouchinsky A. V., Bengtson S., Runnegar B.N., Skovsted C.B., Steiner M., Vendrasco M.J. 2012. Chronology of early Cambrian biomineralization. Geol. Mag. 149:221–251.

References

Burgess Shale fossils Enigmatic prehistoric animal genera Fossil taxa described in 1965 Cambrian genus extinctions {{paleo-mollusc-stub