Alioramus is one of the least well know of the Asian tyrannosaurids. It was a stretch-snouted tyrannosaurid with a very rugose (bumpy) nose. In fact, there seem to be 6 prominent bumps on the nose. It has a very high tooth count (for a tyrannosaur, at 18 maxillary teeth), which lends credence to it being a primitive tyrannosaurid. However, it has a braincase very similar to Tarbosaurus, so who knows where it will end up.
As the name says, it is not a well known tyrannosaurid, and there is even an argument as to whether it belongs as a tyrannosaurid (Carpenter 1992 did not include it). More material is needed to sort it out.