It's described as the T-rex of the deep, a creature with huge razor-sharp teeth it used to "chomp" through its prey off Australia's southern coastline about 25 million years ago.

But what has excited Australian paleontologists and prompted a re-drawing of the world's evolutionary charts is the fact this ancient predator was a baleen whale - the species which today catches tiny shrimps and krill using only a sieve of coarse hair.

Monash University PhD student Erich Fitzgerald, 25, has spent the past three years removing the creature's skull from the rock boulder in which it was found in the late 1990s.