1. The Age of Reptiles (and dinosaurs)
The Mesozoic Era
The Age of Reptiles
(and dinosaurs)

2. The Mesozoic Era is divided into 3 periods, the Triassic, the Jurassic, and the Cretaceous
Ammonite fossils are used as index fossils to date sedimentary rock layers from the Mesozoic.
Changes in ocean environments during the Mesozoic led to many different types of ammonites that existed for short periods of time

4. Mesozoic Earth: Pangea formed during the Permian and lasted into the Jurassic when continents began to shift and break into the continents we see today.
The continental drift that lead to the breakup of Pangea is still happening today

9. The Triassic Period
Pangea continued as a single, large landmass through most of the Triassic period. After a slow recovery from the Permian extinction, many kinds of reptiles evolved. Late in the period, the first mammals appeared.

10. Reptiles were dominant on land and in the sea
Ted Ed: The Game Changing Amniotic Egg
The first dinosaurs evolved from reptiles in the early Triassic
Dinosaurs would not be very diverse until the Jurassic

11. Herrerasaurus

12. Pterosaurs

13. Ichthyosaur

14. Pachypleurosaurus

15. Gymnosperm plants became common
The first mammals evolved from mammal-like reptiles in the late Triassic
First mammals were small, rodent like, and ate insects.
Gymnosperm plants became common
Gymnosperms have seeds without a protective coating
These plants are able to reproduce without a pool of water

16. Megazostrodon
Adelobasilus

18. The Jurassic Period
Pangea continued to split apart during the Jurassic period. Many kinds of dinosaurs evolved and became widely distributed.

20. Hadrosaur

21. Brachiosaur

22. Allosaurus and Stegosaurus

23. Continental drift had caused seas to form in between continents making climates on land less harsh
Fish with scales and fins like modern fish evolved in the seas

25. Dinosaurs developed into a varied and widespread group
They became the dominant land animal
Bird-like dinosaurs with feathers evolved
These dinosaurs could not fly, but were able to glide
Ted Ed: How Did Feathers evolve?

26. Archeopteryx and Pterosaur

27. The Cretaceous Period
The cretaceous is named for the enormous chalk deposits found in Europe
The formed chalked formed by tiny plankton during this period.
“Creta” means chalk in Greek.

28. A greater diversity of life forms evolved during the Cretaceous period
A greater diversity of life forms evolved during the Cretaceous period. Dinosaurs, birds, flowering plants, and small mammals all flourish.

30. Dinosaurs continue to dominate land
Reptiles continued to flourish
Giant snakes
Early Crocodiles that were up to 12 meters long

31. Triceratops

32. Tyrannosaurus rex

34. Mammals continued to diversify

35. Angiosperm plants with flowers appeared on land
- Flowering plants like willow, birch, and sassafras evolved during the cretaceous and are still found today