Chitinozoan Contribution to the Ordovician and Lower Silurian Paleobiogeography

Relationships between various Lower Silurian chitinozoan assemblages are established using statistical methods such as calculation of the number of species in common and similarity coefficient. Conclusions clearly indicate that Eastern Canadian chitinozoan fauna are distinct from those of the north Gondwana margin. The proposed relationships are refined by the use of more rigorous analytical techniques such as correspondence analysis and cluster analysis. The results are compared to the paleogeographic reconstructions available for the Ordovician and the Lower Silurian. They show that chitinozoans are useful not only for stratigraphic correlations, but also, as their paleogeographic distribution seems to be linked to paleolatitudes, they can be used to document plate tectonic dynamics.