@me Beautiful work as always!

1. Nice to see a bit of AMARGASMASH! in there.

2. Does Euhelopus have a tail-club now? I missed that memo!

3. Why such a strongly arched back for Haplocanthosaurus?

@mike

1: YES
2: I think I based it in a Greg Paul skeletal
3: I think I based it in a Greg Paul skeletal

I should probably reference my pictures.

@me That is strange. I have the Greg Paul field guide right here, and his Euhelopus skeletal (page 178) doesn't have a tail at all. Rightly, since it is totally unrepresented in both known specimens.

@mike Okay, fine you made me reach all the way to the shelf and check this. Clearly I was inspired into a bit of speculation based on the questionable Omeisaurus tail club on the next page.

@me I'll allow it :-) in light of a recent phylogeny (I can't remember whose) suggesting that Euhelopus might be a mamenchisaurid after all. (And let's not think too hard about what that does to the clade Euhelopodidae ... according to D'Emic definition I think it would become a synonym of Mamenchisauridae.)

@mike @me I have somehow gotten the impression that Euhelopus jumps back and forth between being a titanosauriform and mamenchisaurid, and yet, as far as I know, these two groups are not thought to be particularly close to each other?

This would seem to indicate Euhelopus is either poorly known, or very strange, or both?

What is going on here?

@llewelly @me Yes: it was recovered as a mamenchisaurid (a group confusingly also knowns as euhelopodids but that begs the question) in Upchurch's early analyses; but Wilson (2002) found it as a basalish titanosauriform and most subsequent analyses, including those of Upchurch, have agreed. Until that recent analysis which infuriatingly I don't remember.

@llewelly @me Why is it so unstable? Not because of a lack of material, it's known from a very good holotype and a decent referred specimen. I guess it's just convergence.

@llewelly @me OK, I got annoyed that I'd lost in, and have now dug it up again: tandfonline.com/doi/full/10.10
Note that the authorship includes Paul Upchurch.

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