Complex sentence: The dead were cremated and the ashes sometimes placed in urns, which had the mid-part in the form of an engraved bulge, in the 1st century AD replaced with a sharp-profiled (with a horizontal ridge around the circumference) shape.
Split into simpler sentences: The dead were cremated and the ashes sometimes placed in urns, which had the mid-part in the form of an engraved bulge. In the 1st century AD this was replaced with a sharp-profiled (with a horizontal ridge around the circumference) shape.