About 600 million years ago, at the end of the Precambrian super-eon, what would later become the Irish landmass was in two parts, with one half on the north-western side of the Iapetus Ocean in Laurentia and the other on the south-eastern side in the micro-continent Avalonia, both at a latitude of around 80° South, close to what is now northwest Africa. From the evidence of the Oldhamia fossils found at Bray Head in Leinster, both parts of Ireland were below sea level at this time.