The Oldest Macroborers: Lower Cambrian of Labrador

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Science  02 Sep 1977:
Vol. 197, Issue 4307, pp. 980-983
DOI: 10.1126/science.197.4307.980-a


We have discovered numerous borings of Trypanites penetrating skeletons and synsedimentary cemented limestones in archaeocyathid reefs of the Forteau formation in southern Labrador. These are, to date, the oldest known macroborings. The discovery of these structures extends the record of large endolithic organisms 100 million years from the Lower Ordovician to the Lower Cambrian. This immediately postdates the appearance of metazoans with hard parts and confirms that endoliths have played a role in reef formation since the early Cambrian.