Estemmenosuchus

Estemmenosuchus (meaning "Crowned Crocodile") is a genus of large, early omnivorous therapsid that lived during the middle part of the Middle Permian period. It was the largest animal of its day, and is characterised by distinctive horns-like structures, probably for intra-specific display. Two species of Estemmenosuchus are known, both from the Perm (or Cis-Urals) region of Russia.

Description
Estemmenosuchus was a large, clumsy-looking animal, the size of an adult bull, with a sprawling posture. The skull is high and massive, and possesses several sets of large horns, looking a little like the antlers of a moose, growing upwards and outwards from the sides and top of the head.

The skull superficially resembles that of Styracocephalus, but the "horns" are formed from different bones; in Estemmenosuchus the horns are located on the frontals and directed upwards, whereas in Styracocephalus the horns are formed by the tabular and extend to the rear.

Two species of Estemmenosuchus are known; they differ in size, shape of the skull, and shape of the horns.

Link

 * Palaeos - detailed description