The southern tyrant lizard is an Australian tyrannosauroid from the late Early Cretaceous of Victoria.

The 100 million year tyrannosauroid lineage is poorly documented. Youngest representatives, the deep-skulled, multiton tyrannosaurids, were the apex predators of latest Cretaceous Laurasia. These are known from abundant, well-preserved fossils.

This situation is changing. A surge of new discoveries is revealing diverse ecotypes and body sizes as early as the Middle to Late Jurassic. This demonstrates that advanced tyrannosauroids with characteristic short arms and powerful jaws achieved a global distribution in the Early Cretaceous.

The length of NMVP186046 (307 mm) is only slightly longer than the pubis of Raptorex [279mm(2)]. Thus, a potentially cosmopolitan grade of small tyrannosauroids with a tyrannosaurid-like body plan preceded the Late Cretaceous rise of the colossal tyrannosaurids.