The Ordovician bioclaustration revolution

Abstract

There was a sudden increase in the diversity of bioclaustrations in the Sandbian (Late Ordovician) that continued somewhat more slowly in the Katian. The Sandbian was also the time when bioclaustrations became common, at least in Baltica. The major increase in the diversity of bioclaustrations in the Late Ordovician was an outcome of the GOBE, and we term it the Ordovician Bioclaustration Revolution. The Ordovician Bioerosion Revolution may partially be responsible for beginning of the Ordovician Bioclaustration Revolution in the Sandbian, as a number of these early bioclaustrations started their growth from initial borings. The diversification of bioclaustrations in the Sandbian involves mostly bryozoans and, to a lesser extent, brachiopods as hosts. The Katian increase in bioclaustration diversity involves mostly corals as the hosts and was likely unrelated or at least less influenced by the Ordovician Bioerosion Revolution. A new broadly conical bioclaustration, Kuckerichnus kirsimaei nov. cgen., nov. csp., is here described from the growth surfaces of hemispherical trepostome bryozoan colonies of Diplotrypa bicornis, Mesotrypa orientalis and Mesotrypa excentrica from the early Sandbian (Late Ordovician) of Estonia.