Monthly Archives: November 2018

Apatosaurus is — still — Just Plain Wrong

We’ve posted a lot here about how crazy the cervical vertebrae of apatosaurines are (for example: 1, 2, 3), and especially the redonkulosity of their cervical ribs. But I think you will agree with me that this is still an arresting sight:

That’s MWC 1946, a mid-cervical from the Mygatt-Moore Quarry that was figured by Foster et al. (2018: fig. 18 A-B) and referred with the rest of the Mygatt-Moore apatosaur material to Apatosaurus cf. louisae (entirely correctly, in my view). This is a ventral view, with the condyle down by the scale bar.

Here’s the same thing cropped from the background to emphasize its unbelievableness:

and mirrored and restored a bit in GIMP to give a taste of its probable appearance in life (if you had an apatosaur, an x-ray machine, and a lot of confidence about not getting stepped on):

For obvious reasons, my nickname for this specimen is the Brontosmasher.

Keep in mind that the centrum was full of air in life, whereas the cervical ribs and the bony struts that support them are just huge slabs of bone. I strongly suspect that the volume of bone in the cervical ribs and their supporting struts is vastly more than in the centrum and neural arch. I will soon have the ability to test that hypothesis–I have this specimen on loan from Dinosaur Journey for CT scanning and 3D modeling. Watch this space.

Many thanks to Julia McHugh at Dinosaur Journey for access to the specimen and assistance during my frequent visits.

Reference

  • Foster, J.R., Hunt-Foster, R.K., Gorman, M.A., II, Trujillo, K.C., Suarez, C.A., McHugh, J.B., Peterson, J.E., Warnock, J.P., and Schoenstein, H.E. 2018. Paleontology, taphonomy, and sedimentology of the Mygatt-Moore Quarry, a large dinosaur bonebed in the Morrison Formation, western Colorado—implications for Upper Jurassic dinosaur preservation modes: Geology of the Intermountain West 5: 23–93.

Academic-Led Publishing: an interview in which I am somehow represented as an expert

Scholastica is a publishing platform that offers support for super-low-cost open-access journals such as Discrete Analysis, led by Tim Gowers. They’re putting together the first Academic-Led Publishing Day on 7 February next year, and as part of the build-up, they kindly invited me to do an interview for them, kicking off their Academic-Led Publishing From the Experts series.

I did tell them that I wasn’t qualified — “I am about as far from an expert as I could possibly be in the field of Academic-led publishing. I’ve never even been an academic editor for a journal, far less started one or run one. All I’ve ever done, really (beyond writing and peer-reviewing articles) is have opinions and write about them.” But they wanted to push ahead anyway, so I was happy to go along with it.

Here’s the interview: enjoy!

 

Pelican cervico-dorsal transition, backlit

What it says on the tin. This is a specimen from the UCMP comparative collection.

I was just going to post this photo with zero commentary, but I can’t help myself. Note that on the two vertebrae in the middle, the crista transverso-obliqua (what in non-avian dinos would be the spinopostzygapophyseal lamina or SPOL) rises higher than either the neural spine apex or the epipophyses. That’s crazy. And it demonstrates something we also see in sauropods, which is that laminae are not merely the plates of bone left behind after pneumatization has scooped all of the unnecessary material out of a normal vertebra–sometimes they are additive structures, too.

If all of that sounded like gibberish, I can sympathize. I spent my first few months as a sauropodologist just learning the lingo (another thing I should blog about sometimes). Here’s a labeled version:

As long as I’m yapping, note the light shining through the honeycombed internal structure of these highly pneumatic vertebrae. For more on the ridiculous pneumaticity of pelican bones, see this post and this one. For more on the homology of bird and sauropod vertebrae, see Wedel and Sanders (2002), and for more on laminae as additive versus reductive structures, see the discussion on pages 210-212 of Wedel (2007).

References

 

Lydekker’s (1893) illustration of Xenoposeidon

Matt’s drawn my attention to a bizarre fact: despite 17 separate posts about Xenoposeidon on this blog (linked from here and here), we’ve never shown a decent scan of Lydekker’s (1893) original illustration of NHMUK PV R2095, the partial mid-to-posterior dorsal vertebra that since Taylor and Naish (2007) has been the holotype specimen of Xenoposeidon proneneukos — and since Taylor (2018) has been known to represent a rebbachisaurid.

Well, here it is at last!

That’s Xeno on the left, of course. On the right, we have one of the various Wealden titanosauriform dorsal vertebrae that were constantly getting referred back and forth between taxa in the late 1800s. I think it might be one of the NPMUK PR R90 vertebrae, perhaps the one that, for disambiguation purposes, I’ve informally named R90a.

Lydekker — or, more likely, an uncredited illustrator — did rather a good job on this, as we can see by juxtaposing the illustration with the now well-known left-lateral photo that’s launched a thousand blog-posts:

The main differences here seem to pertain to how Lydekker and I perceived “lateral”. I think he has the vertebra rotated slightly away from us, so that it’s leaning into the page, and that’s why the centrum appears slightly taller and the arch slightly less tall than in my photo. He seems to have a bit more matrix stuck on the front of the centrum — perhaps because slightly more prep has been done since 1893 — but, worryingly, slightly less bone around the cotyle. I think that can only be illustration error, since that bone is definitely there.

References

 

My new dinosaur book for kids is out

Late last year I got tapped by the good folks at Capstone Press to write a dinosaur book for their Mind Benders series for intermediate readers. Now it’s out. (In fact, it’s been out for a couple of months now, I’ve just been too busy with other things to get this post up.) Covers all the major groups and some of the minor ones, includes a timeline and evolutionary tree, 112 pages, $6.95 in paperback. Despite the short, punchy, 2-3 facts per critter format, I tried to pack in as many new findings and as much weird trivia as possible, so hopefully it won’t all be old news (facts chosen for the cover notwithstanding). Suggested age range is grades 1-6 but who knows what that means; one of the best reviews that Mark Hallett and I got for our big semi-technical sauropod tome was written by a 6-year-old. Many thanks to my editors at Capstone, Shelly Lyons and Marissa Bolte, for helping me get it over the finish line and wrangling about a trillion details of art and science along the way.

If you need a gateway drug or stocking stuffer for a curious kid, give it a look. Here’s the Amazon link (and for teachers, librarians, and my future reference, the publisher’s link).