Circothecidae Explained

Circothecidae are a family of Cambrian problematica, sometimes attributed to the Hyolitha,^[1] though some authors suggest (on the basis of no specified evidence) that they are definitely not.^[2]

Notes and References

1. Brasier, M. D. (1986). The succession of small shelly fossils (especially conoidal microfossils) from English Precambrian–Cambrian boundary beds. Geological Magazine, 123(3), 237–256. doi:10.1017/S0016756800034737
2. Webers, G. F., & Yochelson, E. L. (1989). Late Cambrian molluscan faunas and the origin of the Cephalopoda. Geological Society, London, Special Publications, 47(1), 29–42. doi:10.1144/gsl.sp.1989.047.01.04