 
The four types of Mesozoic reptiles (from Top to
Bottom): Euryapsids, Synapsids, Diapsids. Anapsids (turtles,
etc.) are not pictured.
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Geology:
At the beginning of the Triassic
Period, all of the continents were lumped together into
a large continent called Pangaea. There was no Atlantic
ocean at this time. Approximately 135 million years ago,
this continent broke up into two major landmasses: Laurasia
and Gondwana. 35 million years later, Gondwana broke up into
present-day South America and Africa. The Indian
subcontinent began its 8000-km journey pursuing Asia. 45
million years ago, Australia, like South America, became
independent of Antarctica. This brought about some curious
results (explained in the Cenozoic).
Climate in the Mesozoic was
generally warm and wet.
Animal Life:
Almost anyone who thinks about the Mesozoic
will think "dinosaur" at the
same time. After all, the Mesozoic
has been dubbed "The Age of the Reptiles." You can read more
about these in this era's Creature
Feature. Different types of reptiles existed:
- The Anapsids are the turtles and tortoises. They were
much more numerous then than now, probably because their
shells were oddities in the evolutionary world.
- Euryapsids included the pterosaurs and the reptiles
of the sea.
- Synapsids, mammal-like reptiles, later declined
drastically, but they evolved into mammals.
- Diapsids include all of the dinosaurs,
and other reptiles in the Mesozoic.
Dinosaurs were not the only
ones, though. Insects had large developments, the first
inconspicuous mammals appeared,
and swimming and flying
reptiles conquered the sea and sky.
Plant Life:
Taking advantage of the warm and wet climate, the major
plants were cycads, ferns,
and ginkgoes. Later, in the
Cretaceous, flowering
plants would start to evolve with insect
pollinators.
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