Sometime ago I covered the fantastic series of whale skeletons in the Tokyo Museum and how useful they were to show such a classic evolutionary series as forms adapt and change from an ancestral animal to one far more familiar to people that exists today. The Carnegie has a different version, but one no less often used in text books and websites to illustrate evolution, the origins of the modern horse. Here are a selection of skeletons and with some excellent signs pointing out key transitions etc. and showing how various features have changed. This is rather less dramatic than the changes undergone by whales of course, but then the increased familiarity of the subject makes it perhaps the better study. Either way, it’s great to see.
Incidentally, I’ll be talking museum signs and displays over the next few days. The Carnegie (yes, still) had a plethora of excellent signs and many of them covering things I’ve discussed before and so I want to revel in their excellence and make note of it all. More to come therefore, but in the meantime, here’s a couple of previous posts about museum signs and the like which might be of interest, and especially the comments in the first one:
Dave Hone's Archosaur Musings 
Sorry if this is a dumb question but are those horse skeletons true to size or scaled for demonstration purposes?
No those are the real sizes. Everything there is a cast of a real specimen or a real specimen. Early horses were absolutely tiny.
Wow! Miniature horses don’t seem particularly miniature in comparison.
I worked on a series of horses once, not for the Carnegie but for the University of Minnesota when I was a little kid. They weren’t skeletons, it was just skulls and I got to help with making the molds of the skulls. So this brings back fond memories of being let into Dad’s special world of dead things from long before there were any humans.
The thing I like about horses, as opposed to whales, for this kind of display is that horse skeletons look a lot more like horses that whale skeletons look like whales, so it’s easier to visualise the transition.