The Ordovician Bioerosion Revolution was a dramatic diversification of macroboring ichnotaxa during the Middle and Late Ordovician. This was also a time during which the intensity of carbonate substrate bioerosion greatly increased, reaching a peak in the Late Ordovician and Early Silurian that was not achieved again until the Jurassic. This burst of ichnological diversity was a function of the Ordovician Radiation of marine invertebrates, and it reflects the range and rate of niche differentiation on hard substrates at that time.