This time out, it’s a rather nice cast of a Diplodocus skull at the IVPP. However, it’s mounted on the end of a Mamenchisaurus skeleton which rather reduced the impact.
Still, that’s not as bad as it sounds, for a very long time there was confusion and disagreement about what sort of sauropods were and although there were quite a few specimens known, no Mamenchisaurus had been recovered with anything like a decent skull. Thus not only did we not know what kind of skull they had, it was hard to guess what kind of skull they might have had since their immediate relatives were not known. As a result, you can see a Diplodocus, Shunosaurus or even Apatosaurus skull attached onto a Mamenchisaurus skeleton in various Chinese museums. Since they don’t always have the money to replace them, these things tend to hang around (and replacing a skull on the end of a 10+ m neck is no mean feat either) it’s perhaps no surprise, though can look a bit odd to those who know better.
Those who aren’t in the know will be pleased to find out that in 2002 a very complete and well preserved Mamenchisaurus was described complete with an intact skull. This looks, superficially at least, like those of brachiosaurs with a nice big internarial bar that arches off the top of the skull.