28 May 2014
When We Lack Bones
The consensus is that the body of Jaxartosaurus is extremely similar to that of all other lambeosaurs and, more widely, hadrosaurs as a larger overall group. The facts are that Jaxartosaurus is known mainly from skull material and is differentiated on apomorphies of that skull. The skull material has been questioned, in some circles, because it is similar to other dinosaurs. Obviously, however, the description of Riabinin is definitive enough that it has stood the test of time and kept Jaxartosaurus as a valid genus. When we look at the myriad of skulls in the lambeosaur and hadrosaur lines it is acceptable to think that some ought to be lumped together, but for now this material is different enough that it is separated. Hopefully even more material will be discovered, separated, and add to the repository of what we know about this dinosaur. The crest that we do know of for Jaxartosaurus is much like that of Corythosaurus; it is a low crescent of material superior to the skull.