Page 53 - Prehistoric Animals

Edafo-Saw-Rus

Edaphosaurus

Edaphosaurus (pavement lizard) is a genus of the
extinct edaphosaurid synapsids that lived during the late
Carboniferous to early Permian, around 304 to 275 mil-
lion years ago. It was approximately 3 to 4 metres in
length and weighed around 300 kg.

First named by Edward Drinker Cope in 1882,
Edaphosaurus is one of the earliest known, plant eating,
land vertebrates. The most noticeable feature of
Edaphosaurus is the sail on its back. Other synapsids
from the same period also have tall dorsal sails, like the
predator, Dimetrodon (see page 39 ). However, the sail
on Edaphosaurus is different in shape and structure; no-
tably it had cross-bars on the spines that supported the
fin.

Edaphosaurus had a broad, but small triangular
head with powerful jaws. Its front teeth were long and
serrated, and would have been used for gripping and rip-
ping its food. Its back teeth were short and tightly
packed, ideal for crushing and chewing. It was first
thought Edaphosaurus, dieted on shellfish; however, this
was later revised, when further studies suggest it was
more than likely a plant eater.

Like all sail supporting synapsids, Edaphosaurus
sail has generated its fair amount of speculation and the-
ories. Some say it was used to attract a mate, while others
think it was used to control the body temperature. Used
as an actual sail to blow Edaphosaurus across a body of
water, is another suggestion, while another is, it could
have been used to store fat to survive lean times. With no
living specimen, one can only speculate on the question;
what function did these sails perform?