A 66 million year old infected bone

This is pretty much the first display you see when moving towards the Mosasaur exhibit, it may not look very impressive at first glance but it is rather neatly done.

The infected mosasaur quadrate

The bone you see is a quadrate (I'll get to that), and it's definitely not looking healthy.



The bone had been infected, and quite badly so, the goo in the measuring cup represents half a litre of bone tissue that was eaten away. 

The infected bone, and half a litre of goo

While this must have been extremely painful, it was apparently not lethal. New bone had formed around the infection, showing that this Mosasaurus must have survived the infection.

In reptiles the quadrate bone is part of the jaw joint connecting the upper and the lower jaws (in mammals like us it has become the earbone known as the 'anvil'). Since a Mosasaur would have spent a lot of time biting into things it most have been extremely painful.

The red box marks the location of the quadrate bone

The display is simple but effective, with a short bit of text on the wall behind it explaining what you're looking at. Although I would have appreciated a diagram showing where the bone was located in the skull (but Google is my friend).
Using a common household object to illustrate how much half a litre really helps make it less abstract, especially since the content really does look like the detritus that would have filled the cavity (or pancake batter)