Topic summary
Cambrian fauna
Extracted from the Wikipedia article Evolutionary fauna.
Cambrian fauna
Fauna I, known as "Cambrian", described as a "Trilobite-rich assemblage", encompasses the bulk of the fossils which first appeared in the Cambrian explosion, and largely became extinct in the Ordovician-Silurian extinction event. This fauna comprises trilobites, small shelly fossils (grouped by Sepkoski into "Polychaeta", but including cribricyathids, coleolids, and volborthellids), Monoplacophora, inarticulate brachiopods and hyoliths.