The Sunday after SVP, Brian Engh and I visited the museum in Albuquerque. I was quite taken with the mounted T. rex. It’s waaaay more interesting and dynamic than any other T. rex mount I’ve seen. It even beats the “Rockette rex” in Denver (which I really like and need to blog about), by virtue of putting the body and head down at eye level where you can study them up close.

The only thing I don’t like about this mount is that it has the dumb teeth-hanging-out-too-far thing going on. Why the heck people don’t fix that, I have no idea. Like, even if that’s the way the jaws are molded, cut off the excess and glue the crowns back up where they belong. Or fix the friggin’ mold. It’s not like the problem hasn’t been obvious for decades.

On the upside, pretty much everything else about this mount is awesome. Brian and I spent a fair amount of time working through the muscle attachments and thinking about how bulky the animal would have been in life. The answer is “very”.

Pretty cool to think that a fleshier, more aggro version of this was the last thing that many animals ever saw. And by ‘cool’ I mean ‘terrifying’.

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In my recent visit to the LACM herpetology collection, I was interested to note that almost every croc, lizard, and snake vertebra I saw had a pair of neurovascular foramina on either side of the centrum, in “pleurocoel” position. You can see these in the baby Tomistoma tail, above. Some vertebrae have a big foramen, some have a small foramen, and some have no visible foramen at all. Somehow I’d never noticed this before.

This is particularly interesting in light of the observation from birds that pneumatic diverticula tend to follow nerves and vessels as they spread through the body. Maybe we find pneumatic features where we do in dinosaurs and pterosaurs because that’s where the blood vessels were going in the babies. Also, these neurovascular foramina in extant reptiles are highly variable in size and often asymmetric – sound familiar?

It should. Caudal pneumaticity in the tail of Giraffatitan MB.R.5000. Dark blue vertebrae are pneumatic on both sides, light blue vertebrae only have fossae on the right side. Wedel and Taylor (2013b: Figure 4).

I am starting to wonder if some of the variability we associate with pneumaticity is just the variability of soft tissue, full stop. Or if pneumaticity is variable because it developmentally follows in the footsteps of the blood vessels, which are themselves inherently variable. That seems like a promising line of inquiry. And also something I should have though of a lot sooner.

I am still building up to a big post on vertebral orientation, but in the meantime, check out this caudal vertebra of a Komodo dragon, Varanus komodoensis. This is right lateral view–the vert is strongly procoelous, and the articular ends of the centrum are really tilted relative to the long axis. I find this encouraging, for two reasons. First, it helped me clarify my thinking on how we ought to orient vertebrae, which Mike wrote about here and here. And second, it gives me some hope, because if we can figure out why tilting your articular surfaces makes functional sense in extant critters like monitors, maybe we can apply those lessons to sauropods and other extinct animals.

This is LACM Herpetology specimen 121971. Many thanks again to Neftali Camacho for access and assistance, and to Jessie Atterholt for basically doing all the other jobs while I was faffing about with this Komodo dragon.

Juvenile Tomistoma schlegelii, LACM Herpetology 166483, with me for scale. It wasn’t until I picked up the skull that I realized it was the same specimen I had looked at back when. I was looking at its neck in 2011, and its tail today, for reasons that will be revealed at the dramatically appropriate moment. I was only playing with the skull because it’s cute, an intricate little marvel of natural selection. Photos by Vanessa Graff (2011) and Jessie Atterholt (2018). Many thanks to collections manager Neftali Camacho for his hospitality and assistance both times!

Left lateral view

Have we ever posted decent photos of the Brachiosaurus altithorax caudals? Has anyone? I can’t remember either thing ever happening. When I need images of brachiosaur bits, including caudals, I usually go to Taylor (2009).

Taylor (2009: fig. 3)

Which is silly, not because Mike’s diagrams compiling old illustrations aren’t good – they definitely are – but because I’m sitting on a war chest of decent photos of the actual material. I am home sick with a sore throat today, and I can’t be arsed to (1) follow up on the “Down in Flames” post, (2) add anything thoughtful to the vertebral orientation discussion, or (3) crop or color-adjust these photos. You’re getting them just as they came out of my camera, from my trip to the Field Museum in 2012.

Here are the rest of the orthogonal views:

Right lateral view

 

Anterior view

 

Posterior view

 

Dorsal view of caudal 1

 

Dorsal view of caudal 2

And here’s a virtual walkaround using a series of oblique shots. Making a set like this is part of my standard practice now for important specimens during museum visits.

 

 

 

 

 

 

 

Now, I said up top that I wasn’t going to add anything thoughtful to the vertebral orientation discussion. I have thoughts on that, but I’m tired and hopped up on cold medicine and now ain’t the time. In lieu of blather, here are a couple of relevant photos.

 

I wanted to capture for my future self the pronounced non-orthogonality of the neural canal and centrum, so I rolled up a piece of paper and stuck it through the neural canal. I haven’t run the numbers, but in terms of “angle of the articular faces away from the neural canal”, these verts look like they’re right up there with my beloved Snowmass Haplocanthosaurus.

More on that next time, I reckon. In the meantime, all these photos are yours now (CC-BY, like everything on this site [that someone else hasn’t asserted copyright over]). Go have fun.

Reference

John Yasmer, DO (right) and me getting ready to scan MWC 8239, a caudal vertebra of Diplodocus on loan from Dinosaur Journey, at Hemet Valley Imaging yesterday.

Alignment lasers – it’s always fun watching them flow over the bone as a specimen slides through the tube (for alignment purposes, obviously, not scanning – nobody’s in the room for that).

Lateral scout. I wonder, who will be the first to correctly identify the genus and species of the two stinkin’ mammals trailing the Diplo caudal?

A model we generated at the imaging center. This is just a cell phone photo of a single window on a big monitor. The actual model is much better, but I am in a brief temporal lacuna where I can’t screenshot it.

What am I doing with this thing? All will be revealed soon.

I was back in Utah the week before last, looking for monsters with Brian Engh and Jessie Atterholt. It was a successful hunt – more about that another time.

We made a run to Fruita, Colorado, to visit Dinosaur Journey. I was just there in May, picking up Haplocanthosaurus caudals for CT scanning (and other fun things). We picked up another specimen this time, for a different project – more on that in another post, too.

Not this one, but like this one. An apatosaurine middle caudal vertebra, MWC 5742, in left lateral view.

There’s a nice ceratopsian exhibit up at Dinosaur Journey right now, with cast skulls from many of the new ceratopsians that have been described in the past couple of decades. My near-favorites were Zuniceratops and Diabloceratops, both of which are small enough that they must have been adorable in life (think pony-sized and big-horse-sized, respectively).

My absolute favorite, of course, was this little thing:

I can tell you exactly how Aquilops came to be on display there. Julia McHugh printed a copy of the holotype, because it’s freely available to the world. And she used Brian’s Aquilops head recon in the signage (correctly, with attribution), because it’s also freely available to the world. In fact, I’ve seen Aquilops on display at several museums now for just those reasons. So, folks, if you want your critters to be seen, make them open. Hiring a paleoartist to do some awesome artwork that can be released under a CC-BY license (because you paid them, not because you asked them to give their art away for “exposure”) is a huge help.

We had to geek out a little about unexpectedly finding ‘our’ dinosaur on display:

But of course it is not our dinosaur anymore – that’s the whole point. Aquilops belongs to the world.

For more on our trip, see Jessie’s posts herehere, and here.