heated and erupted with volcanism.The warm, weakened crust consequently
broke apart into several major continents between 630 and 560 million years
ago, although their shapes differed from the continents of today.The breakup
of the supercontinent created thousands of miles of new continental margin,
which might have played a major role in the explosion of new life at the
beginning of the Phanerozoic.
After covering life in the Proterozoic, the next chapter takes a look at
the invertebrate life-forms and rocks of the Cambrian period.
PROTEROZOIC METAZOANS