DIMETRODON (Dim-et-ro-don)
One of the oldest of the dinosaurs is Dimetrodon.
He lived during the Permian Period over 2 hundred
million years ago. His large dorsal fin was a pro-
trusion of his vertebrae. The membrane between
these protrusions was a temperature control. He
was not a fully developed land animal and depen-
ded on the water for his source of food and his pro-
tection especially from the sun.
PREHISTORIC FOREST, Route U.S. 163, 8 miles
east of Port Clinton, Ohio, on the Marblehead
Peninsula. .
PF-2
Aero Distributing. Evanston, Illinois 60201
133704
