Faunal migrations of archaeocyaths and early Cambrian plate dynamics

Global palaeogeographic reconstructions for the early Cambrian can be const rained by the faunal distribution. The inferred pathways of archaeocyathan migrations coupled with the application of Jaccard's similarity coefficient to total local faunas supports the palaeogeographic reconstructions sugges ting the existence of East and West Gondwana in the early Cambrian and rift ing of Laurentia from Australian-Antarctic margin of East Gondwana (SWEAT h ypothesis). A drift, of suspect terranes provides some further constraints for the understanding of the palaeozoogeography. The delayed appearance of Siberian archaeocyath assemblages in the suitable facies of Central Asian t erranes was due to the restriction of these terranes to East Gondwana. The total combination of tectonic, facies, and palaeomagnetic data suggests tha t these fragments were drifted from East Gondwana to Siberia during the ear ly Cambrian.