Albertosaurus sarcophagus is the least well known of the North American tyrannosaurids. As far as I know, there is only one skeleton that is reasonably complete. There is only skull material, no whole skulls have been found (although I do not know how much material is in RTMP81.10.1). I know that this is not unusual for dinosaurs, but all of the other North American tyrannosaurids have at least one or two complete skulls. There was a bonebed discovered by the AMNH early in the century, but only a partial skull and a few feet were collected. The bonebed was lost for many years, but has been recently discovered. I am told by Dr. Jim Kirkland that there is a lot of material which is well preserved. There is a group going this summer (1998) to dig it up. Hopefully, this will answer many questions about Albertosaurus that are still left.
There is a composite mount of Albertosaurus for sale from the Royal Tyrrell Museum of Paleontology. The picture in the catalogue is hard to see, but I like the mount. I am not sure where the mount is displayed (I thought it was in the Tyrrell, but my trip there in the summer of 1997 proved that this was not the case).
Albertosaurus is probably a direct descendant of Gorgosaurus, but it seems to be more gracile and shorter in the snout. There are few things that differentiate the two, but the newest study being done should clarify the matter.
Albertosaurus is much more likely to be preserved as an incomplete skeleton than Gorgosaurus, but I have no idea why. It is also not as well known as Gorgosaurus.