Proto-Germanics were the Bastarnae? The ancestry of Germanics is
well known and can be traced in prehistory thousands of years before the
classics were written. There was a people called the Battle-Axe People,
or Corded Ware people. They were extremely tall, robust,
dolichocephalic and had huge brains. They once extended from the Volga
to Holland. One group of them invaded Denmark, where they conquered the
Ertebølle Folk. The people of Jutland were mostly descended from the
Battle Axe People, but the people of the Danish Islands were
predominantly descended from the Ertebølle Folk. From this home in
Denmark the Proto-Germanics slowly expanded. They moved into
southernmost Sweden and then began a long Drang nach Norden into Sweden
and Norway where they displaced some kind of Uralic people. A few of
them moved along the Baltic coast of Germany. Only much later did they
move south into Germany and conquer various Celtic and Slavic peoples.
The Bastarnae, whoever they were, were much later; they were in the
wrong place and the wrong time to be the Proto-Germanics.
http://www.delphi.com/prehistory