The sacrum of Brachiosaurus

May 12, 2012

In my 2009 brachiosaur paper, I gave rather short shrift to the sacrum of Brachiosaurus — in part because there is no really good sacrum of Giraffatitan to compare it to. Also my own photos of the sacrum, taken back before I figured out how to photograph big bones, are all pretty terrible.

Happily, Phil Mannion took some much better photos and gave us permission to use them. So I prepared this multi-view figure, which we plan to use in a forthcoming paper about another sacrum:

Brachiosaurus altithorax FMNH P25107 sacrum, from photos by Phil Mannion

At the bottom, we have the sacrum in left lateral view; above it, in dorsal view. To the left is the anterior view (with dorsal to the right) and the right is the posterior view (with dorsal to the left). The idea of this composition is that you could print the image out, and cut and fold it into a cuboid.  (In fact I might just do that.)

As usual with these things, click through for the much more impressive full-resolution version (3809 x 3157 pixels).

8 Responses to “The sacrum of Brachiosaurus

  1. Mike from Ottawa Says:

    How big a sheet would you need to make one life size?

  2. Matt Wedel Says:

    How big a sheet would you need to make one life size?

    Heh–a bedsheet. King size might do it.

  3. Nima Says:

    Wow nice! Beautiful pic. Gives a much better idea than Riggs’s blurry pics do of how this sacrum was distorted during fossilization.

    Now I have to go back and edit my B. altithorax skeletal: LOL If only I’d known this was going up I’d have waited instead of guessing what the sacrum looked like from above… *scratches head*

  4. Mike Taylor Says:

    “If only I’d known this was going up …”

    If only we’d known, we’d have told you. But we generally don’t know we’re going to post here until we find out. We currently have 59 unfinished drafts, and all of those are constantly getting leapfrogged by whatever happens to catch our eye at a given moment.

  5. Nima Says:

    Ahh gotcha. Here’s the fixed up version.

  6. Nima Says:

    …including top view. Tilting it in dorsal perspective produces some interesting effects. The flat sacral ribs actually look in some ways more like a Huanghetitan sacrum than a Giraffatitan sacrum.

  7. […] of 9.14 m compared with Janensch’s 7.62 for Giraffatitan. Riggs (1904) tells us that the sacrum of Brachiosaurus is 0.95 m long, which is slightly less than 1.07 m for Giraffatitan. Finally, since we know […]

  8. […] are also given in the paper. I comped in the sacrum of Brachiosaurus altithorax FMNH P25107 from this post (many thanks to Phil Mannion for the photos!), and scaled it according to the max width across the […]

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