Too small you say? Well, better in this case to have erred on the side of caution, I suppose. Can’t wait to hear more, and I’ll be certain to revise it again then!

I’ve never heard of any other A. fragillimus material, but that could just mean that I haven’t heard the rumors. Near as I can tell, the type vertebra is the only specimen mentioned in the literature.

Regarding the legitimacy of Cope’s measurements—Wikipedia’s entry on the genus suggests that the “Bone Wars” between Cope and Marsh may have led Cope to either inadvertently or deliberately exaggerate the size of the specimen. That is the only source I know of that uses the conflict to cast doubt on the size of A. fragillimus. While both Cope and Marsh engaged in less-than-rigorous scientific behavior, without further proof to the contrary I’m inclined to give Cope the benefit of the doubt.

Ultimately, I don’t think that it causes much debate, certainly not enough to have researchers lining up on one side or another. Were there 160-foot diplodocids roaming the Jurassic West? Did Cope exaggerate his measurements in order to ’scoop’ his rival? Both scenarios are possible, and they are not mutually exclusive. But without a specimen, all arguments are moot.

One thing that I think is cool about the new titanosaurs—they show that animals of such stature are physically possible, and they did exist!

As an aside: I first heard of A. fragillimus several years ago, from a friend who was at the time a paleontology grad student, and who currently is (I hope) a working paleontologist somewhere. At the time he said it was known from the original partial vertebra “and rumored other material,” and he spoke of it as if it was a rock solid thing. So I’m a bit irritated to find that it’s known only from the original vertebra, that the fossil itself is lost, and that there’s an argument over whether or not it’s legitimate. Is the argument a real one, with sound reasoning on both sides? Or is it like the dinosaur-bird argument, with most workers in the field lined up on one side and only a few determined rogues on the other?

Another aside: if what I’ve heard is right, losing a sauropod fossil apparently isn’t all that hard, and ironically it’s precisely because they’re so bloody big. They’re so big and so expensive to prepare and mount that unless they’re good specimens, they aren’t worth the cost. So they simply get put into storage and forgotten. Brigham Young University has something like 120 tons of unprepared bones stored away. A large chunk of that collection is sauropod bits.