Map of the later North Atlantic region after the Caledonian/Acadian orogenies. Fossil species on both side of the red line differ for the Cambrian and Ordovician periods, this is evidence for the existence of a former ocean (Iapetus Ocean) before the time Pangaea was created.
Reconstruction and location of fossils based on:

.mw-parser-output .smallcaps{font-variant:small-caps}Windley, B.F.; 1996: The Evolving Continents, John Wiley &amp; Sons (3rd ed.), ISBN-10: 0471917397
Ziegler, P.A.; 1990: Geological Atlas of Western and Central Europe, Shell Internationale Petroleum Maatschappij BV (2nd ed.), ISBN 90-6644-125-9.
Own work
Woudloper