This just in from John Conway:

John doesn’t say much about it in the tweet where he unveiled this piece: just “A new #painting, of a Saltapotamus”. His website is just a little more forthcoming:

Saltapotamus

Saltasaurus was a small (for a sauropod) sauropod from the Late Cretaceous of Argentina. It had a some armour, and a lot of girth.

This reminds me very strongly of Obesethocoelicaudia, a fat restoration of Opisthocoelicaudia that John kindly did for Matt and me to use in our 2014 SVPCA talk, “Slender Giants”:

(Saltasaurus and Opisthocoelicaudia are both derived titanosaurs, and in most phylogenies they come out as pretty closely related.)

Is this kind of restoration credible? After all, it’s a long way from how we’ve been used to seeing Saltasaurus. Here, for example, is how E. Guanuco restored a group of four Saltasaurus individuals in Powell (2003: plate 78):

In this illustration they are tubby in a Normanpedia kind of way, but nothing very different from how (say) Apatosaurus was being restored not too long before then.

But the truth is that lots of animals have flesh envelopes very different from what you might predict based on the skeleton alone. Exhibit A, the inspiration for John’s new piece: the humble hippopotamus. Skeleton:

And life appearance:

It seems more than reasonable that across a clade as diverse, disparate and long-lived as the sauropods, there would have been some that were similarly heavy with flesh. In fact, I think it would be special pleading to argue that there were not.

Which specific sauropods were obese? That is much harder to tell. Hippos can be very heavy with little penalty as they spend much of their time in the water. Perhaps the same was true of some sauropods. If that’s so, then our quest must be for sauropods whose skeletons show adaptations for a semi-aquatic lifestyle, and on that basis Opisthocoelicaudia may have at least two feature supporting this interpretation: very robust limb bones and (if the interpretation of Borsuk-Bialynicka 1977: figure 5 is to be trusted) a transversely broad torso.

References

  • Powell, Jaime E. 2003. Revision of South American Titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum 111:1-94.

 

As John himsef admits in the tweet that announced this picture, it’s five years late … but I am prepared to forgive that because IT’S NEVER TOO LATE TO BRONTOSMASH!

As always, John’s art is not just scientifically accurate, but evocative. Here’s a close-up of the main action area:

As you see, he has incorporated the keratinous neck spikes that we hypothesized, based on the distinct knobs that are found at the ventrolateral ends of apatosaurine cervical rib loops.

John has also incorporated a lot of blood — which is exactly what you get when elephant seals collide:

By the way, if John’s BRONTOSMASH! art can be said to be five years late — so can the actual paper. It was of course at SVPCA 2015 that we first presented our apatosaur-neck-combat hypothesis (Taylor et al. 2015), and it’s not at all to our credit that nearly five years later, we have not even got a manuscript written. We really need to get our act together on this project, so consider this post my apology on behalf of myself, Matt, Darren and Brian.

Reference

  • Taylor, Michael P., Mathew J. Wedel, Darren Naish and Brian Engh. 2015. Were the necks of Apatosaurus and Brontosaurus adapted for combat?. p. 71 in Mark Young (ed.), Abstracts, 63rd Symposium for Vertebrate Palaeontology and Comparative Anatomy, Southampton. 115 pp. doi:10.7287/peerj.preprints.1347v1