The enigmatic Edaphosaurus, aka the
"pavement lizard," will not be 
tread on! Like many other prehist-
oric critters, there were several
species of Edaphosaurus that spanned
across multiple geologic periods:
from the Carboniferous to the
Permian. The largest species could
grow to an impressive three meters
long! Despite sporting a similar
sail to the Permian predator
Dimetrodon, Edaphosaurus was 
actually a gentle herbivore. The 
name "pavement lizard" refers to its
densely-packed teeth, which sat in
deep jaws that sported mighty
muscles. Ferns must have quivered 
with fear when they saw the formid-
able Edaphosaurus appear!

During the Carboniferous, Edapho-
saurus lived in iconic rainforests
called coal forests (named for the
fact that its plant matter became
coal). The species that lived in the 
Permian period still inhabited lush 
marshes, but experienced gradual 
global warming and drying as the 
planet transitioned to hot, dry 
deserts. Although some researchers 
hypothesized that its large sail was
useful for cooling the body, it was
likely used for either fat storage 
or display instead. The "pavement
lizard" paraded its sail across a 
large range, extending across much 
of the modern United States, only 
vulnerable to falling prey to large
predators like Dimetrodon.