Happy Xenoposeidon day!  Today, November 15, 2008, is the one-year anniversary of the publication of Xenoposeidon Taylor and Naish 2007.

By happy coincidence, I’ve just been sent a courtesy copy of Kids Only, a new guide-book for the Natural History Museum … and there is Xenoposeidon on page 5, exemplifying dinosaur diversity.  Rock!

nhm-kids-only-p5-xenoposeidon-500px

It’s good to see our baby out there educating people!

For much more of Xeno, see Xenoposeidon week.

Internal structure of a cervical vertebra of Sauroposeidon, OMNH 53062. A, parts of two vertebrae from the middle of the neck. The field crew that dug up the bones cut though one of them to divide the specimen into manageable pieces. B, cross section of C6 at the level of the break, traced from a CT image and photographs of the broken end. The left side of the specimen was facing up in the field and the bone on that side is badly weathered. Over most of the broken surface the internal structure is covered by plaster or too damaged to trace, but it is cleanly exposed on the upper right side (outlined). C, the internal structure of that part of the vertebra, traced from a photograph. The arrows indicate the thickness of the bone at several points, as measured with a pair of digital calipers. The camellae are filled with sandstone.

Image and caption recycled from fig. 14 here. Hat tip to Mike from Ottawa for the wonderful title.

Addendum (from Mike)

What Matt’s failed to mention is that this section of prezygapophyseal ramus is one of the elements for which he calculated the Air-Space Proportion (ASP) in his chapter in “The Sauropods”. As shown in his table 7.2, this calculation yielded 0.89.  Just think about that for a moment.  89% of the bone was air.  Yikes.

It’s interesting that this was the only prezygpapophyseal ramus in the survey, and that it had a way higher value that any of the other elements considered, which topped out at 0.77, i.e., more than twice as much bone as this specimen.  So maybe all prezyg rami are ridiculously pneumatic? So far (as far as I know) no-one’s measured the ASP of another ramus, so the answer remains, for now, ridiculously unknown to our planet.

Special bonus weirdness

Basal sauropodomorph wizard Adam Yates has posted an entry on his blog showing more sauropod vertebrae/ceratopsian frill convergence, as follow-up to our own recent post. Too weird.

The remarkable object shown here (the one on the left) is a copy of the famous BYU 9044 bone. I know you’ve all heard the story a million times before: it’s the stuff of late-night parties, and fireside stories-from-grandpa, but it would be wrong not to recount it again. First described by Jensen (1985) as the holotype of the new brachiosaurid Ultrasaurus macintoshi (a name that was later changed to Ultrasauros macintoshi), it was much later shown – by Curtice et al. (1996) – to belong not to a brachiosaur, but to a diplodocid. Furthermore, because it was found literally among the bones of the holotype of the diplodocid Supersaurus vivianae, the most logical course of action was to, alas, sink Ultrasauros into Supersaurus… and hence Ultrasauros was no more.

Jensen (1985) figured the vertebra in right lateral view, so the left-hand view you’re getting here is the sort of thing that has sauropod vertebra fans swooning and lying awake at night. There is, of course, a ton of neat anatomy to talk about here.. but I don’t have time to talk about it. You will no doubt have been impressed by the size: the scale is kindly provided by Sam Heads of Palaeoentemology and Insect Evolution.

References

  • Curtice, B., Stadtman, K. L. & Curtice, L. J. 1996. A reassessment of Ultrasauros macintoshi (Jensen, 1985). In Morales, M. (ed) The Continental Jurassic. Museum of Northern Arizona Bulletin 60, 87-95.
  • Jensen, J. A. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. Great Basin Naturalist 45, 697-709.

Special Bonus: Non-Sauropod Saurischian Vertebra Picture Of The Week!

Hi, Mike here. It’s a bit rude to tag onto the end of Darren’s post, but I don’t want to make a brand new post and shove Ultrasaurus, er, Ultrasauros off the front-page. Anyway, I’ve made available my close-up photos of a turkey cervical. Click through the image for details. Enjoy!

Turkey cervical C7 multiview on white background

When we were planning to start this blog, Matt wrote to Darren and me saying “I am thinking that we should keep the text short and sweet” — an aspiration that we have consistently failed to live up to. Not today!

Here is Omeisaurus tianfuensis. Even by sauropod standards, that neck is just plain crazy.

fig. 63)

Omeisaurus tianfuensis skeletal reconstruction, from He et al. (1988:fig. 63)

This figure is lifted from an awesomely comprehensive monograph — 173 pages including the front-matter and plates — which gives the lie to the idea that all Chinese dinosaurs are woefully inadequately described. It’s true that with the recent glut of theropods, the thing seems to be to rip ’em out of the ground, throw toegther a two-pager for Science or Nature and move on to the next one; but sauropods understandably inspire more devotion from their followers, resulting in careful work like this monograph and the similar work by Ouyang and Ye (2002) on Mamenchisaurus youngi. So hats off to He, Ouyang and their colleagues — showing how it should be done!

Special bonus photo

Home-made sushi

Home-made sushi

References

  • He, X., K. Li, and K. Cai. 1988. The Middle Jurassic dinosaur fauna from Dashanpu, Zigong, Sichuan, vol. IV: sauropod dinosaurs (2): Omeisaurus tianfuensis. Sichuan Publishing House of Science and Technology, Chengdu, China. 143 + 20 plates pp.
  • Ouyang, H., and Y. Ye. 2002. The first mamenchisaurian skeleton with complete skull: Mamenchisaurus youngi. Sichuan Science and Technology Press, Chengdu, China. 111 + 20 plates pp.