The Therapsids

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Pangea  —  One Big Dinocephalian World
The dinocephalians migrated throughout their new world – and such large animals can travel great distances.*  Their size had other advantages, too.  Almost all dinocephalians possessed big (but compact) bodies. This heat-conserving form resulted in the later dinocephalians looking more than a little like a beach ball with legs!  [see below]

Efficiency in movement came from thick, powerful hind-legs — the sprawling forelimbs' function was primarily steering. The 'high walk' of the dawn therapsids became the normal striding gait of  the dinocephalians.  And stride they did!

The direction of these dinocephalian migrations is unclear. It was believed that all therapsids arose in the north, then wandered south. But, the story is probably more complex.*

Globetrotting Dinocephalian — Ulemosaurus goes Walkabout  [above]
The common characteristics of later dinocephalians were the short neck and tail, and a tubby, near-spherical torso. Very similar features are seen in elephants today.  Body heat-loss was reduced by two developments in the dinocephalians. First, by simply growing larger.  A bigger animal, by virtue of its greater mass alone, has a more stable body temperature. It loses (or gains) heat more slowly.  Second, by reducing the animal's surface area  —  body heat is lost through the skin and a short neck or tail has less skin area. Of course, conserving energy is only one aspect of maintaining body heat  —  another is processing sufficient food to fuel that large body.

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Dinocephalian Teeth
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