Probably everyone who reads SV-POW! already knows that the manus, or forefoot, or sauropods was very distinctive.  The metacarpal bones, rather than being splayed out horizontally as in the forefeet of most animals, were arranged more or less vertically in a horseshoe shape, hence the characteristic shape of sauropod manus prints.

This was first recognised by Osborn (1904), a paper which contains the greatest single sentence in any scientific paper:

My previous figures and descriptions of the manus are all incorrect.

Here is the rather beautiful illustration from that paper (fig. 1):

It depicts the right manus, in anterior view,  of AMNH 965, “Morosaurus” sp.  As described by Osborn and Mook (1921:376-377), that genus was subsequently synonymised with Camarasaurus by Mook (1914), following the earlier suggestion of Osborn (1898), and this synonymy is universally accepted — for now, at least.

If anything, trackway evidence suggests that this illustration shows the metacarpals insufficiently vertical, resulting in the manus being too splayed out.

I have nothing more to say about that; just wanted to post the illustration because it’s beautiful and out of copyright (so feel free to use it however you want!)


  • Mook, Charles C.  1914.  Notes on Camarasaurus Cope.  Annals of the New York Academy of Science 24:19-22.
  • Osborn, Henry F.  1898.  Additional characters of the great herbivorous dinosaur Camarasaurus.  Bulletin of the American Museum of Natural History 10: 219-233.
  • Osborn, Henry F.  1904.  Manus, sacrum and caudals of Sauropoda.  Bulletin of the American Museum of Natural History 20:181-190.
  • Osborn, Henry Fairfield, and Charles C. Mook.  1921.  Camarasaurus, Amphicoelias and other sauropods of Cope.  Memoirs of the American Museum of Natural History, n.s. 3:247-387, and plates LX-LXXXV.