Page 147 - Science Course 3 (Book 2)
P. 147
Mo11-L6b: Fossil Evidence About Mesozoic Era
Key Concept Fossils indicate that other large vertebrates swam in
the seas and f ew in the air.
Fossil Evidence About Mesozoic Era
How did the Rocky Mountains form?
Plesiosaurs were Mesozoic marine reptiles with
small heads, long necks, and f ippers.
Pterosaurs were Mesozoic f ying reptiles with large,
batlike wings.
Mesozoic Life
Dinosaurs were dominant Mesozoic land vertebrates
that walked with legs positioned directly below their
hips.
Mammals evolved early in the Mesozoic and
remained small in size throughout the era.
The Mesozoic era ended 65 mya with a mass
extinction called the Cretaceous extinction event.
Scientists hypothesize that some dinosaurs are more SUMMARY
closely related to present-day birds than they are to
present-day reptiles. Fossil Evidence About Mesozoic Era
Dinosaurs were not the only large vertebrates
that lived during the Mesozoic era.
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