Eotitanosuchus
olsoni -Tchudinov, 1960- skull
Therapsida: Eotheriodontia:
Eotitanosuchidae
Locality: Ocher, Perm Region, eastern
European Russia
Age: Late Permian, 255 million years ago
Meaning of name: "Ancient
giant crocodile"
The
dangerous enemies of the peaceful plant-eating eotheriodonts
were the predatory
eotheriodonts of the genus Eotitanosuchus.
It was preserved in flood deposits
containing many skeletons of estemmenosuchids.
The skull
displayed in The Russian Dinosaur Exposition is of a juvenile
animal.
An adult skull would likely reach about 1 metre in length.
This mammal-like
reptile was quite primitive in that the temporal opening just behind
the eye socket
in the skull was small. The temporal opening is the site for
the attachment (insertion)
of the masses of muscle that closed the lower jaw.
In more advanced mammal-like
reptiles, the temporal opening is larger, thus
allowing for a large suite of muscles,
and thus a stronger.and more versatile bite.
These sabertoothed predators exceeded
the modern tiger in size and could probably
swim well. Their long legs helped
them to move quickly on the coastal bogs.
Estemmenosuchus
and Eotitanosuchus have been found only in East Europe.
The more advanced therapsids,
the dinocephalians, existed in the
southern megacontinent Gondwana at the same
time.
In the middle Late Permian Gondwana and Laurasia became connected by
a
land bridge as result of which the dinocephals had entered in the territory of
East
Europe and replaced the eotheriodonts in corresponding niches. 
