When I was a dinosaur-obsessed kid growing up in Albuquerque in the nineties, I used to spend a lot of time at the New Mexico Museum of Natural History. There, in the main exhibit hall for dinosaur bones, there were a few mounted casts of full skeletons and a smaller display case to the side showing a few vertebrae of what was said to be possibly the biggest dinosaur of them all: Seismosaurus, which had been discovered in New Mexico only a few years before and was still being prepared and studied. This was a big deal at the time, at least locally, and I had wondered over the years whatever became of it. Now Brian Switek has the answer with an interesting post explaining how it was determined that Seismosaurus was actually smaller than initially thought and therefore not a new species but just an unusually large Diplodocus. The picture illustrating his post shows the fully mounted Seismosaurus skeleton in that same exhibit hall, which seems to have been substantially changed since I last saw it, and a post he links to with more details confirms that the full skeleton was mounted in 2004. A bit disappointing compared to the hype when it was first found, but interesting nonetheless.