2. Spikes And Tusks
Some reptiles grew rows of spikes on their heads.
Some dinosaurs used spikes as display for mates.
Some reptiles who had spikes breathed through their
skin.
3. Sail-back reptiles
There were multiple types of sail-back reptiles such as
the Dimetrodon living at once.
They could run very fast, despite their sizes.
The sails may have been used to control body heat.
4. Boomerang heads
Some were very tiny. The smallest was 3ft(1m).
The horns on their heads may have been used to fight.
The horns also may have acted as underwater steering
fins.
5. Steamy swamps
In these areas, millipedes grew up to 6ft.
Ferns also grew very huge, the tallest being 180 ft tall.
Many amphibians such as the Hylonomus lived in
swamps such as these.
