A vaucheriacean alga from the middle Neoproterozoic of Spitsbergen: implications for the evolution of Proterozoic eukaryotes and the Cambrian explosion

A -walled from the middle Neo- Svanbergfjellet Formation, Spitsbergen, identified as a assemblage rep- -phase a vaucheriacean xanthophyte alga. such, it range additional criteria with which to vaucheriaceans and confirms the identification Palaeovaucheria in the Formation. Pronounced taxonomic inflation, form-taxonomy, suggests overall estimates of diversity Proterozoic need to be . Combined with for low levels of extended stasis, pre-Cambrian eukaryotes seen to evolve at a fundamentally rate than their Phanerozoic . slower turnover accounts for the "delayed" animals without external constraints. The Cambrian acceler- of was a direct animals, whereas the slower overall rates of the Proterozoic absence of earlier metazoans.