Mackinnonia

Mackinnonia is a genus of small shelly fossil comprising straight or slightly coiled shells of the helcionelloid type.[1] The outer surface of their shell is smooth, whereas the inner surface has a net-like ridges.[1] They are known from late Early Cambrian rocks across North America and Greenland.[1]

Mackinnonia Temporal range: Late Early Cambrian[1] PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	†Helcionelloida
Order:	†Helcionelliformes
Family:	†Helcionellidae
Genus:	†Mackinnonia Runnegar 1980
Species
M. taconica (Landing & Bartovski 1996) Skovsted & Peel 2007 M. rostratum Zhou & Xiao 1984 (type)

References

1. Christian B. Skovsted; John S. Peel (2007). "Small shelly fossils from the argillaceous facies of the Lower Cambrian Forteau Formation of western Newfoundland". Acta Palaeontologica Polonica. 52 (4): 729–748.

• Fossil Focus: The place of small shelly fossils in the Cambrian explosion