A case for two late Proterozoic–earliest Cambrian faunal province loci

Comparison of the geographic ranges of certain benthic members of the Ediacaran fauna and the earliest shelly metazoan assemblages suggests that the benthic Ediacaran fauna and the first shelly faunas inhabited different parts of the late Proterozoic world. Although Ediacaran cnidarians seem to have been cosmopolitan, the benthic Ediacaran fauna appears to have been restricted to Proto-Gondwana (Baltica and Gondwana), and remained isolated from Proto-Laurasia (Siberia, China, and North America), where shelly metazoans first appeared. Late Proterozoic rifting events and continental motions, perhaps corresponding to fragmentation of a Proterozoic supercontinent, provide a mechanism for isolation of Proto-Gondwana and Proto-Laurasia and resulting benthic metazoan provincialization.