Extremes of climate have been experienced at various points during the Earth's history.
Evidence of prehistoric life can be found only in the fossil record.
Mammoth bones were initially believed to belong to a much different creature.
Mammoth remains have been preserved particularly well in Siberia because of the natural climate there.
Mammoths were known to our ancestors.
The first discoveries of "Terror Birds" led people to believe they were extremely large.
Phorusrhacos was able to migrate because of continental drift.
Terror birds were hunted by dinosaurs.
Reconstructions and conclusions about prehistoric birds are more difficult to make.
Modern humans were first found in European areas about fifty thousand years ago.
Most of what is known about Cro-Magnons comes from their bones.