Tutorial 15c: The bones of the ornithischian skeleton
July 18, 2013
Readers with long memories might recall that, nearly two years ago, we published annotated skeletal reconstructions of Camarasaurus and of Tyrannosaurus, with all the bones labelled. At the time, I said that I’d like to do an ornithischian, too.
Well, here it is at last, based on Marsh’s (1891) classic reconstruction of Triceratops:
Click through for the full-sized version (2076 by 864 pixels), which — like the other two — you are welcome to print out and hang on your wall as a handy reference, or to use in teaching. (Marsh’s original is out of copyright; I hereby make my modified version available under the CC By 3.0 licence.)
Sauropod Vertebra Picture of the Week 
July 18, 2013 at 11:14 pm
Does anybody talk about what a hellacious ulna that is? Was it doing handstands or something, that it needed so much support up front?
July 18, 2013 at 11:20 pm
IIRC, Bakker discusses it right back in The Dinosaur Heresies, and it’s part of his argument that ceratopsians could gallop. I’ll leave it to ceratopsian specialists to comment on that possibility.
July 21, 2013 at 2:10 am
Nah, clearly the giant ulna is to handle the stresses imposed by karate chops…
July 23, 2013 at 5:17 am
I tend to hurry past the dinosaurs in a museum in my rush to get to the fossil mammals, so I haven’t looked at a Triceratops skeleton carefully in a long time…. But the forwardly-directed pubis surprised me here: I had naively assumed that a retroverted pubis was standard in onithischians (and was part of what earned them the name).
July 23, 2013 at 1:48 pm
Many ornithischians “re-saurischianed” their pubis, at least superficially, by creating a big prepubic process–that’s what you’re seeing on the picture. The original retroverted portion is still there, but it is splint-like, tucked up against the ischium, and not even visible on this image.
July 24, 2013 at 1:06 am
Andy Farke–
Thank you! I’ve looked at “re-saurischianized” (great word!) pelves in other ornithischian taxa (and noticed the word “pubis” next to the ischium on another Triceratops skeleton image I found on the WWW), but worried about this one. … Side view doesn’t show something important: these prepubic processes diverge, don’t they? (Somewhere on the net there’s a Tric pelvis shown from another angle…) They don’t form a single “pelvic boot” like the pubes of … the other famous Maastrichtian dinosaur from western North America with a generic name beginning with “T”.
July 24, 2013 at 9:25 am
Yes, that’s correct: the prepubic processes diverge rather than converging into a “prepubic boot”. This picture shows it quite clearly.
March 8, 2014 at 9:13 am
[…] never done either of those — but we should, to go with our Camarasaurus, Tyrannosaurus and Triceratops. Skeletal homology for the […]