As illustrated in this diagram, in addition to the match of the coastlines, the
distribution of fossils of dinosaurs and plants, as well as a variety of rock types and other
geological features on opposite sides of large oceans could be matched
together -- once the continents were restored into a single continent --
the supercontinent of Pangaea, which existed over 200 million years ago.
Clearly there was a large,
growing body of evidence to support the movement of continents, but data
was missing from nearly 70% of the Earth's surface -- the portion that
lies below the sea.