Brontosaurus cervical 8 … it just gets weirder
June 19, 2015
A while back, we noted that seriously, Apatosaurus is just nuts, as proven by the illustrations in Ostrom and McIntosh (1966: plate 12).
Now I’m posting those illustrations again, in a modified form, to make the same point. Here ya go:
Here’s what’s changed since last time:
- “Apatosaurus” excelsus is Brontosaurus again!
- I cleaned up the scans of the plates, removing all the labels
- In the lateral view, I added a reconstruction of the missing neural spine, based on that of Apatosaurus louisae (from Gilmore 1936: plate XXIV). This reconstruction first appeared in Taylor and Wedel (2013a: figure 7).
- Most importantly, I added the ventral view of the vertebra from plate 13. Only now can you properly appreciate the truly bizarre shape of this bone. (The prezygs appear to project further forward than they should because the illustrated aspect is not true ventral, but slightly anteroventral.)
If only those three views were enough to construct a 3D model by photogrammetry! Sadly, it’s not possible to get photos of the whole vertebra from different angles now, as it’s tied up in the mounted Brontosaurus skeleton at the YPM:
The bottom line: these are some
crazy-ass morphologically distinctive vertebrae. Those ventrolaterally projecting processes that bear the cervical ribs are, for my money, the single most distinctive feature of apatosaurine sauropods. And they reach their zenith (or maybe their nadir, since they point downwards) in Brontosaurus. These processes are the reason that apatosaurs had Toblerone-shaped necks — triangular in cross-section, with the base flat or even concave. Any restoration that shows a tubular neck is way off base.
- Gilmore Charles W. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300 and plates XXI–XXXIV.
- Ostrom, John H., and John S. McIntosh. 1966. Marsh’s Dinosaurs. Yale University Press, New Haven and London. 388 pages including 65 absurdly beautiful plates.
- Taylor, Michael P., and Mathew J. Wedel. 2013. Why sauropods had long necks; and why giraffes have short necks. PeerJ 1:e36. 41 pages, 11 figures, 3 tables. doi:10.7717/peerj.36