long canine teeth projecting from their mouths. Mammal-like reptiles called
dicynodonts also had two caninelike tusks and fed on small animals along
riverbanks. Small reptiles probably ate insects similar to the way modern
lizards do.
The Pangaean climate was one of extremes.The northern and southern
regions were colder than Siberia. The interior deserts were hotter than the
Sahara and almost devoid of life. The massing of continents together created
an overall climate that was hotter, drier, and more seasonal than at any other
time in geologic history.These conditions might have led to the mass extinc-
Figure 117The effect of
geography on the
migration of species.CARBONIFEROUS AMPHIBIANSNORTH
AMERICASOUTH
AMERICAAFRICAEURASIA