In a word, amazingly. After 6 days (counting public galleries last Sunday), 4300 photos, 55 videos, dozens of pages of notes, and hundreds of measurements, we’re tired, happy, and buzzing with new observations and ideas.

We caught up with some old friends. Here Mike is showing an entirely normal and healthy level of excitement about meeting CM 584, a specimen of Camarasaurus from Sheep Creek, Wyoming. You may recognize this view of these dorsals from Figure 9 in our 2013 PeerJ paper.

We spent an inordinate amount of time in the public galleries, checking out the mounted skeletons of Apatosaurus and Diplodocus (and Gilmore’s baby Cam, and the two tyrannosaurs, and, and…).

I had planned a trip to the Carnegie primarily to have another look at the Haplocanthosaurus holotypes, CM 572 and CM 879. I was also happy for the chance to photograph and measure these vertebrae, CM 36034, which I think have never been formally described or referred to Haplocanthosaurus. As far as I know, other than a brief mention in McIntosh (1981) they have not been published on at all. I’m planning on changing that in the near future, as part of the larger Haplocanthosaurus project that now bestrides my career like a colossus.

The real colossus of the trip was CM 555, which we’ve already blogged about a couple of times. Just laying out all of the vertebrae and logging serial changes was hugely useful.

Incidentally, in previous posts and some upcoming videos, we’ve referred to this specimen as Brontosaurus excelsus, because McIntosh (1981) said that it might belong to Apatosaurus excelsus. I was so busy measuring and photographing stuff that it wasn’t until Friday that I realized that McIntosh made that call because CM 555 is from the same locality as CM 563, now UWGM 15556, which was long thought to be Apatosaurus excelsus but which is now (i.e., Tschopp et al. 2015) referred to Brontosaurus parvus. So CM 555 is almost certainly B. parvus, not B. excelsus, and in comparing the specimen to Gilmore’s (1936) plates of CM 563, Mike and I thought they were a very good match.

Finding the tray of CM 555 cervical ribs was a huge moment. It added a ton of work to our to-do lists. First we had to match the ribs to their vertebrae. Most of them had field numbers, but some didn’t. Quite a few were broken and needed to be repaired – that’s what I’m doing in the above photo. Then they all had to be measured and photographed.

It’s amazing how useful it was to be able to reassociate the vertebrae with their ribs. We only did the full reassembly for c6, in part because it was the most complete and perfect of all of the vertebrae, and in part because we simply ran out of time. As Mike observed in his recent post, it was stunning how the apatosaurine identity of the specimen snapped into focus as soon as we could see a whole cervical vertebra put back together with all of its bits.

We also measured and photographed the limb bones, including the bite marks on the radius (above, in two pieces) and ulna (below, one piece). Those will of course go into the description.

And there WILL BE a description. We measured and photographed every element, shot video of many of them, and took pages and pages of notes. Describing even an incomplete sauropod skeleton is a big job, so don’t expect that paper this year, but it will be along in due course. CM 555 may not be the most complete Brontosaurus skeleton in the world, but our ambition is to make it the best-documented.

In the meantime, we hopefully left things better documented than they had been. All of the separate bits of the CM 555 vertebrae – the centra, arches, and cervicals ribs – now have the cervical numbers written on in archival ink (with permission from collections manager Amy Henrici, of course), so the next person to look at them can match them up with less faffing about.

We have people to thank. We had lunch almost every day at Sushi Fuku at 120 Oakland Avenue, just a couple of blocks down Forbes Avenue from the museum. We got to know the manager, Jeremy Gest, and his staff, who were unfailingly friendly and helpful, and who kept us running on top-notch food. So we kept going back. If you find yourself in Pittsburgh, check ’em out. Make time for a sandwich at Primanti Bros., too.

We owe a huge thanks to Calder Dudgeon, who took us up to the skylight catwalk to get the dorsal-view photos of the mounted skeletons (see this post), and especially to Dan Pickering, who moved pallets in collections using the forklift, and moved the lift around the mounted skeletons on Tuesday. Despite about a million ad hoc requests, he never lost patience with us, and in fact he found lots of little ways to help us get our observations and data faster and with less hassle.

Our biggest thanks go to collections manager Amy Henrici, who made the whole week just run smoothly for us. Whatever we needed, she’d find. If we needed something moved, or if we needed to get someplace, she’d figure out how to do it. She was always interested, always cheerful, always helpful. I usually can’t sustain that level of positivity for a whole day, much less a week. So thank you, Amy, sincerely. You have a world-class collection. We’re glad it’s in such good hands.

What’s next? We’ll be posting about stuff we saw and learned in the Carnegie Museum for a long time, probably. And we have manuscripts to get cranking on, some of which were already gestating and just needed the Carnegie visit to push to completion. As always, watch this space.



Four huge beasts

March 13, 2019

Left to right: Allosaurus fragilis, Apatosaurus louisae, Homo sapiens, Diplodocus carnegii.


March 13, 2019

Separated at birth.

Left: Apatosaurus lousiae holotype CM 2018, cast skull associated with specimen. Right: Matt Wedel. Scientists have long wondered how such a bloated beast could etc. etc.

This one.

No time for a long post today, but there are a couple of cool developments I wanted to let you know about. The folks at the Barnes & Noble Settlers Ridge store in Pittsburgh got in touch and asked if I’d give a short talk and do a book signing while I’m in town. That will be this coming Sunday, March 10, at 1:00 PM, in the children’s section at that store, which is located at 800 Settlers Ridge Center Drive. They’ll have copies of my big sauropod book with Mark Hallett, and my kid’s book that came out last fall. Come on out if you’re in the area and interested.

And this one.

In other news, the excellent Medlife Crisis channel on YouTube recently did a video on the recurrent laryngeal nerve and gave a nice shout-out to my 2012 paper. The video is five minutes long and — in my heavily biased opinion — well worth a watch:

Darren covered this briefly on the Scientific American version of Tetrapod Zoology, but the photos seem to have gone down and who knows how much longer any of that stuff will be up. Plus, he had other things to discuss, so the story has never been told in its entirety. This happened back in April, 2014. Here’s the full writeup I sent to Darren and Mike about it back when:

This happened Sunday afternoon and I thought you’d be interested. London and I let our box turtle, Easty (Terrapene carolina triunguis), crawl around the front yard on sunny days — with supervision, of course. She loves to dig around the edge of the sidewalk and flower bed and eat wood lice, worms, and whatever else comes her way. Sunday we saw her biting this biggish thing that from a distance looked like crumpled up paper. She was really going at it, so I got close to see what she was munching on. It was the head of a rat that our cat, Moe, had killed last week. Easty was snapping off bits of the braincase and eating them.

I had read of turtles scavenging carcasses for minerals but this was the first time I had observed it myself. She kept at it for about 20 minutes, until all of the thin, easily broken parts of the braincase were gone. She didn’t attempt to eat any of the facial skeleton or basicranium. Once she was done, she was done — I tossed the skull in front of her a couple of times and she would stop to smell it, but then walk past it, or even over it on one occasion.

So, there you have it, turtle eats part of rat skull. In keeping with my resolution to blog more about turtles, I’ll try to get some video of Easty feeding later this year. Right now she’s hibernating in a plastic tub on the bottom shelf of our refrigerator, so the hot turtle-feeding action will have to wait. Watch this space!

P.S. The gray ring on Easty’s shell in these photos is a sort of bathtub ring, from soaking in her water dish with just the top of her shell exposed, which she does for about six hours a day when she’s not hibernating. For pictures of Easty with a cleaner shell, please see the previous post. She really is a beautiful turtle.

Cool new paper out today by Yara Haridy and colleagues, describing the oldest known osteosarcoma in the vertebrate fossil record. The growth in question is on the proximal femur of the Triassic stem turtle Pappochelys.

Brian Engh did his usual amazing job illustrating this pervert turtle with no shell and a weird growth on its butt.

I don’t have a ton more to say about the paper, it’s short and sweet. I got to meet Yara in person at SVP last fall and learn about her research, and there is going to a LOT more weird stuff coming down the pike. She is after some really fundamental questions about where bone comes from, how it develops in the first place, and how it remodels and heals. Get ready to see some crazy jacked-up bones from other basal amniotes in the next few years, including some vertebrae that are so horked that Yara and I spent some time discussing which end was which.

On a probably inevitable and purely selfish personal note, I don’t blog nearly enough about turtles. I like turtles. Which, if you’re going to say, you gotta say like this kid:

In fact, I love turtles, and if there were no sauropods, I’d probably be working on turtles. Other people show you pictures of their cats, I’m going to show you pictures of my turtle, Easty. She’s a female three-toed box turtle, Terrapene carolina triunguis.

Here she is closing in on an unlucky roly-poly (or pill bug, if you prefer).

Having a close encounter with our cat Berkeley last summer. I think Easty kinda blew Berkeley’s mind. She’s been around our other cat, Moe, for years, so she’s completely unfazed by cats. But Berkeley is a SoCal kitty who showed up on our doorstep starving and yowling when he was about eight weeks old, so this was his first encounter with a turtle.

Berkeley batted at Easty’s shell a couple of times and then spent about half an hour having a visible existential crisis. Here was a small creature that he couldn’t frighten and couldn’t move, which was not the least bit afraid of him and either ignored him or treated him like an obstacle. Watching them interact — or rather, watching Easty act and Berkeley react — was solid entertainment for most of the afternoon.

Why have I hijacked this post to yap about my turtle? Primarily because up until now I’ve had a hard time visualizing a stem turtle. Turtles are so much their own thing, and I’ve been so interested in them for virtually my entire life, that imagining an animal that was only partly a turtle was very difficult for me. The thing I like most about Brian’s art of the tumorous Pappochelys is that it reads convincingly turtle-ish to me, especially the neck and head:

So congratulations to Yara and her coauthors for a nice writeup of a very cool find, and to Brian for another vibrant piece of paleoart. Triassic turtles sometimes had cancer on their butts. Tell the world!

Since I’ve already blown the weekly schedule here in the new year, maybe my SV-POW! resolution for 2019 will be to blog more about turtles. I’m gonna do it anyway, might as well make it a resolution so I can feel like I’m keeping up with something. Watch this space.


In short, no. I discussed this a bit in the first post of the Clash of the Dinosaurs saga, but it deserves a more thorough unpacking, so we can put this dumb idea to bed once and for all.

As Marco brought up in the comments on the previous post, glycogen bodies are probably to blame for the idea that some dinosaurs had a second brain to run their back ends. The glycogen body is broadly speaking an expansion of the spinal cord, even though it is made up of glial cells rather than neurons — simply put, help-and-support cells, not sensory, motor, or integration cells. When the spinal cord is expanded, the neural canal is expanded to accommodate it; as usual, the nervous system comes first and the skeleton forms around it. This creates a cavity in the sacrum that is detectable in fossils.

avian lumbosacral specializations - glycogen body

Giffin (1991) reviewed all of the evidence surrounding endosacral enlargements in dinosaurs (primarily sauropods and stegosaurs) and concluded that the explanation that best fit the observations was a glycogen body like that of birds. I agree 100%. The endosacral cavities of sauropods and stegosaurs (1) expand dorsally, instead of in some other direction, and (2) expand and contract over just a handful of vertebrae, instead of being more spread out. Of the many weird specializations of the spinal cord in birds, the glycogen body is the only one that produces that specific signal.

If any part of the nervous system of birds and other dinosaurs might be described as a ‘second brain’, it wouldn’t be the glycogen body, it would be the lumbosacral expansion of the spinal cord, which really is made up of neurons that help run the hindlimbs and tail (more on that in this previous post). But there’s nothing special about that, it’s present in all four-limbed vertebrates, including ourselves. Interestingly, that bulk of extra neural tissue in the sacral region of birds was referred to as a sort of ‘second brain’ by Streeter way back in 1904, in reference to the ostrich, but it’s clear that he meant that as an analogy, not that’s it’s literally a second brain.

So to sum up, a gradual expansion of the spinal cord to help run the hindlimbs and tail IS present in dinosaurs — and birds, and cows, and frogs, and us. But if that qualifies as a ‘second brain’, then we also have a ‘third brain’ farther up the spinal cord to run our forelimbs: the cervical enlargement, as shown in the above figure. These spinal expansions aren’t actual brains by any stretch and referring to them as such is confusing and counterproductive.

The sharp expansion of the neural canal over just a few vertebrae in birds does not house a ‘second brain’ or even an expansion of the neural tissue of the spinal cord. It contains the glycogen body, which is not made of neurons and has no brain-like activity. The sacral cavities of non-avian dinosaurs replicate precisely the qualities associated with the glycogen bodies of birds, and there’s no reason to expect that they contained anything else. That we don’t know yet what glycogen bodies do, even in commercially important species like chickens, may make that an unsatisfying answer, but it’s what we have for now.

The next installment will be way weirder. Stay tuned!


  • Giffin, E.B.,1991. Endosacral enlargements in dinosaurs. Modern Geology 16: 101-112.
  • Streeter, G.L. 1904. The structure of the spinal cord of the ostrich. American J. Anatomy 3(1): 1-27.