Plateosaurus pes

Since I seem to be writing about saurischian feet a lot at the moment, I might as well continue and bring you this Plateosaurus pes. Obviously we’ve moved some way from derived theropods and down into the ‘prosauropods’. Still, there are some interesting things here which throw up echoes of the ancestry of this group. While Plateosaurus was one of the most derived and biggest prosauropods, it’s feet are, in a few ways, quite what you would expect from something that diverged not *so* long ago from a small, cursorial predator.

First off the claws are rather big and quite sharp. While obviously even quite derived sauropods can have big claws on the feet, including especially large and pointed ones on the first toe, these are rather more narrow and curved. The fifth toe is also rather reduced with a short metatarsal and just a nub of one phalanx so there’s not much going on here. It’s hard to imagine this foot carrying a huge amount of weight as the metatarsals are relatively compact, and their disjunct lengths and positions would not do too well under major loads.

4 Responses to “Plateosaurus pes”

  1. 1 Heinrich Mallison 04/05/2011 at 9:11 am

    Ohhhhhhh… now you move into my territory 🙂
    This is a cast displayed where? Do you happen to know of which specimen?

    As can be easily seen on this so-so mounted example (OK as far as the metatarsus goes; astragalus is in the wrong place!), Plateosaurus was leaving tridactyl prints with the middle digit much longer than the others (so assigning all those semi-plantrigrade tetradactyle tracks to prosauropods in the Triassic of Central Europe may be a tad rash).
    As for carrying weight: the metatarsus does look like the uneven distal end is bad for carrying much weight. But in fact, the proximal ends and quite massive, and fit tightly and with quite a lot of contact area. MT2 and MT3 are here not properly articulated, btw, seems they were cast as found, not as they belong.
    Distally, the phalanges do a good job of evening out the line of contact with the ground. Not a bad job, considering that the heaviest realistic estimates for P. are in the 4 ton area.

    may I point you to Fig. 6 in this publication: ?

    • 2 David Hone 04/05/2011 at 9:20 am

      Hi Heinrich, I guessed you’d be along soon after I put this up!

      This is a specimen mounted in the Bristol musum so you might have seen it at SVP a couple of years back, but i have no idea which one it’s based on. All i can say is that it’s not the Munich one as I know that quite well and this looks different to my eye.

      As for the weight bearing issue of the metatarsala, I was really just commenting on the fact that these just aren’t *that* robust. I did play a lot with the Munich one and yeah, I was amazed to see that despite the uneven lengths and sizes of the various MTs you could get them to pretty much lock together. They were surprisingly ‘tough’ in that sense.

  2. 3 Heinrich Mallison 05/05/2011 at 2:13 pm

    Thanks, Dave, I never managed to see the Bristol museum during that SVP 😦 shame on me….. I guess it is an AMNH 6810 cast.

    On the robustness – it seems we fully agree: this in not a sauropod foot, or that of a basal ungulate with easily visible consolidation of elements. It looks very basal, not made for a multi-ton animal.

  1. 1 Mamenchisaurus ungual « Dave Hone's Archosaur Musings Trackback on 07/05/2011 at 9:35 am
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