Page 79 - Prehistoric Animals

Mast-Odon-Sorus

Mastodonsaurus

Mastodonsaurus (teat tooth lizard) is an ex-
tinct genus of temnospondyl amphibian and was named by, G.
F. Jaegar in 1828. It lived (Mostly in Europe) in the Middle Tri-
assic, from around 230 million to 190 million years ago. Its size
has earned it the reputation of being the largest amphibian ever
known; the various species of the genus measured around 4 me-
tres, for the smallest, to the largest at 6 metres or 20ft.

When first discovered Mastodonsaurus was thought to be
a land based animal, however, as more fossils were unearthed it
soon became clear the makeup of its body was suited more for
living in the water. If it did venture on land it would have been
for only very short periods.

Mastodonsaurus has often been displayed with a short
stocky body and tail. However, as more details of its body
emerged it became clear its body and tail, although large, were
much longer. Its large body is supported by four very short legs.
These short legs would have made it difficult for Masto-
donsaurus to support its large body on land. They are more suit-
ed for walking in shallow waters; the water giving the body the
buoyancy it needed.

Mastodonsaurus had a huge, broad, flat head. Its large
eyes were on top and to the rear of this long head. These are ide-
ally positioned for it to see above water as it swam along just be-
neath the surface, or lay on the bottom watching for its prey to
swim passed overhead. It had large jaws lined with rows of short
sharp pointed teeth. Its jaws had one peculiar addition. At the
front of the jaws it had several sets of tusk-like teeth, two of
which were very long and grew upwards from the lower jaw.
These would protrude through the front of the upper jaw when
the jaws were closed.

Fossilized evidence has shown that Mastodonsaurus lived
on fish, small amphibians and there is evidence of cannibalism
by adults on juveniles. It probably also snatched and ate small
land-living animals that dallied at the water’s edge. There is also
evidence that Mastodonsaurus itself was preyed on by large
quadrupedal reptiles, like Batrachotomus. They would either be
snatched from the water or attacked when they got stranded on
the bottom of dried-up lakes.

Much has still to be learnt about this sometime controver-
sial species and the place it occupied in the development of early
animals. If nothing else, Mastodonsaurus has turned out to be a
very thought provoking species