A real deceptive reptile

Apatosaurus ajax is the type species of Apatosaurus ("deceptive reptile"), so if someone ever manages to resurrect Brontosaurus (which is tied to A. excelsus), this animal won't be changing its name. The skeletal is a long-needed revision to the skeletal I did for a paper I and colleagues published on Supersaurus back in 2007 (we subsequently dropped it from the final paper).

The reconstruction is based on NSMT-PV 20375, a specimen on display in Tokyo (thankfully I had the opportunity to made a couple trips to see it). Like the type specimen it's not full grown, and it's probable that the animal would have "grown into" its fairly long limbs as it got larger. How much larger? Possibly quit a bit larger, as most of the largest reported specimens have been at least tentatively referred to A. ajax, although it's hard to be certain without proper descriptions.

Despite this, it seems evident that A. ajax wasn't as robust as A. excelsus, and it wasn't close to being the overbuilt steroid-user that A. louisae was [link]

Interestingly it also seems to retain the smaller pelvis and found in Supersaurus [link] although whether this has any phylogenetic value isn't clear.

Either way, this is the species that should actually be driving our understanding of Apatosaurus, and that makes it pretty darned interesting in my book.