Apatosaurus cervical ribs and the tyranny of 2D images
December 8, 2022
Some quick backstory: lots of sauropods have long, overlapping cervical ribs, like the ones shown here in Sauroposeidon (diagram from this old post):
These long cervical ribs are ossified tendons of ventral neck muscles, presumably longus colli ventralis. We know they’re ossified tendons because of their bone histology (Klein et al. 2012), and we suspect that they’re longus colli ventralis because those tendons look the same in birds, just less ossified, as in this rhea (same specimens as these even older posts: 1, 2):
Diplodocoids have apomorphically short cervical ribs, which never extend very far past the end of their respective centra and sometimes don’t overlap at all. Still, we assume the long ventral neck muscles were there, just without long ossified tendons. Which brings me to Apatosaurus, which has cervical ribs that are anteroposteriorly short but famously massive, extending very below and/or to the sides of the cervical centra — for a truly breathtaking example see this post. Here are C3 through C7 in CM 3018, the holotype of Apatosaurus lousiae (Gilmore 1936: plate 24):
At least for me, it’s hard to resist the temptation to mentally scoot those vertebrae together into articulation, and imagine that the very swoopy-looking and maybe even down-turned cervical ribs allowed the ventral tendon bundles to wrap around the bottom of each cervical rib protuberance, something like this:
But it’s just not so, because like all 2D images, Gilmore’s plate distorts 3D reality. If you get to see the mounted skeleton in person, it’s clear that the cervical ribs are all more or less in line, and none of them are pointed at the big protuberances, which stick way out ventrolaterally.
Here I’ve drawn in the likely trajectories of the longus colli ventralis tendons. My little red pathways don’t precisely match the cervical ribs as mounted, but there’s a lot of distortion and restoration going on. For example, comparing with Gilmore’s plate we can see that the cervical ribs of C5, which point downward compared to all the others, only do that because someone forced them to — the whole anterior portion of the rib, where the shaft would actually join to the capitulum and tuberculum, is reconstructed. Even if I’m a little off, it’s clear that the cervical ribs shafts point backward, they’re all more or less in two parallel lines, and none of them point down and out toward the ventrolateral processes. The photo contains a mountain of useful morphological information that you’d never get from the lateral views.
My takeaways from all this:
- If a person has only seen 2D images of a specimen, and especially if those 2D images have only been orthogonal views with no obliques, their little island of knowledge is surrounded by at least a sizeable lake of ignorance, if not a small ocean.
- That doesn’t mean that seeing specimens in person is the only antidote — 3D models and 3D prints are extremely useful, and for specimens that are difficult to manipulate because of their size or fragility, they may be more useful than seeing or handling the specimen, at least for some questions.
- For Apatosaurus specifically, those ventrolateral processes cry out for explanation. They’re fairly solid knobs of bone that stick way out past the ossified tendons of the ventral-most neck muscles. That’s a super-weird — and super-expensive — place to invest a bunch of bone if you’re not using it for something fairly important, especially in a lineage that had just spent the last 80-100 million years making their necks as light as possible.
- Pursuant to that last point, we’re now in — ugh-ouch-shame — our 8th year of BrontoSMASH!!, with still just the one conference presentation to show for it (Taylor et al. 2015). Prolly time we got moving on that again.
References
- Klein, N., Christian, A., & Sander, P. M. (2012). Histology shows that elongated neck ribs in sauropod dinosaurs are ossified tendons. Biology letters, 8(6), 1032-1035.
- Taylor, M.P., Wedel, M.J., Naish, D., and Engh, B. 2015. Were the necks of Apatosaurus and Brontosaurus adapted for combat? 63rd Symposium on Vertebrate Palaeontology and Comparative Anatomy, Meeting Proceedings, p. 71, and PeerJ PrePrints 3:e1347v1. https://doi.org/10.7287/peerj.preprints.1347v1
John Conway’s BRONTOSMASH!
August 4, 2020
As John himsef admits in the tweet that announced this picture, it’s five years late … but I am prepared to forgive that because IT’S NEVER TOO LATE TO BRONTOSMASH!
As always, John’s art is not just scientifically accurate, but evocative. Here’s a close-up of the main action area:
As you see, he has incorporated the keratinous neck spikes that we hypothesized, based on the distinct knobs that are found at the ventrolateral ends of apatosaurine cervical rib loops.
John has also incorporated a lot of blood — which is exactly what you get when elephant seals collide:
By the way, if John’s BRONTOSMASH! art can be said to be five years late — so can the actual paper. It was of course at SVPCA 2015 that we first presented our apatosaur-neck-combat hypothesis (Taylor et al. 2015), and it’s not at all to our credit that nearly five years later, we have not even got a manuscript written. We really need to get our act together on this project, so consider this post my apology on behalf of myself, Matt, Darren and Brian.
Reference
- Taylor, Michael P., Mathew J. Wedel, Darren Naish and Brian Engh. 2015. Were the necks of Apatosaurus and Brontosaurus adapted for combat?. p. 71 in Mark Young (ed.), Abstracts, 63rd Symposium for Vertebrate Palaeontology and Comparative Anatomy, Southampton. 115 pp. doi:10.7287/peerj.preprints.1347v1
Steve White’s impressionist BRONTOSMASH!
August 17, 2019
Darren Naish, the silent third partner in SV-POW!, alerted me to this piece by palaeoartist Steve White:
In his own words, this piece is “Not what I set to do but was an interesting excercise”.
I for one am glad it came out the way it did!
I’m loving the gnarliness of the necks. Yes, it’s overdone — but it’s a much-needed corrective to the long-established habit of artists depicting sauropod necks as tubes.
(For more on the palaeobiological hypothesis that Steve’s artwork is illustrating, see the BRONTOSMASH! index.)
BRONTOSMASH! in a kids’ book
February 15, 2019
Thanks to a comment from long-time reader Andrew Stuck, I realised he is also the tweeter @dinodadreviews, who pointed us to Xenoposeidon in a kids’ book. Now, a review on his website of Ted Rechlin‘s comic-book Jurassic has pointed me to what I think is the first depiction of the BRONTOSMASH! hypothesis in a kids’ book:
This is nice work: it captures the mass of the animals, and resists the nearly ubiquitous tendency to make their necks too slender and elegant. The necks do look rather too short here, but I think we can explain that away as perspective foreshortening.
You’d have to say, though, that it owes more than a little inspiration to the third of Brian Engh’s early sketches:
I suppose there are only a certain number of ways to draw two apatosaurs fighting.
Anyway, it’s great to see what we consider a solidly supported palaeobiological hypothesis out there influencing young hearts and minds. We should also take this as a well-deserved prod to get on with the actual paper, which after all was meant to follow hard on the heels of our 2015 SVPCA presentation.
By the way, folks: the spelling and punctuation is “BRONTOSMASH!”. Not “Brontosmash”, not “BRONTOSMASH”: all in capitals, with an exclamation mark. It’s “the BRONTOSMASH! hypothesis”.
Apatosaurus is — still — Just Plain Wrong
November 30, 2018
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.
#MikeTaylorAwesomeDinoArt at TetZooCon 2018
October 11, 2018
The afternoon of Day 1 at TetZooCon 2018 was split into two parallel streams: downstairs, some talks that I would have loved to see; and upstairs, a palaeoart workshop that I was even keener not to miss out on.
There were talks by Luis Rey (on how palaeoart has had to be dragged kicking and screaming into accepting feathers and bright colours) and by Mark Witton (on the future of palaeoart — sadly, bereft of slides). Both fascinating.
But better still was the wide-ranging informal discussion between Luis, Mark, John Conway, Bob Nicholls and others on what palaeoart is actually all about. For Luis, it’s basically fun; for Mark, it’s primarily science communication; for John, it’s art first, and palaeontology only because that’s what he happens to be depicting; and for Bob, as well as all those things, it’s crucially important as a job of work, satisfying the requirements of those who commission that work. Obviously that’s a huge over-simplification: all of them have all these aspects going on in varying proportions. But that’s how I read it.
At the same time that all this was going on, we — maybe 60 or 70 of us? — were encouraged to create our own art, either attempting styles that are different to what we usually do, are using materials we’re not so familiar with. For the many excellent artists in the group, this challenge must have been interestingly novel. For non-artists like myself, it was just a chance to play.
I took the opportunity to try my hand with charcoal, in the hope of getting some suggestive or even impressionistic textures. Here’s my first work — an indeterminate brachiosaur with an inexplicably big head.
Aside from the head — I can’t do heads! — I’m reasonably happy with that. I got a decent sense of bulk in the torso, anyway.
Encouraged, I made a start on a second piece: a BRONTOSMASH!ing apatosaur that didn’t come out so well.
I’m happy with the forelimbs here, but something is dreadfully wrong with the torso and I can’t put a finger on what it is. If I’d had more time, I’d have put in the second hindlimb, which might have helped me figure out what was going wrong. The other thing I fluffed here was that I should have made the neck even fatter and more robust. Oh, and of course the head. I might return to this and see if I can sort out, if I can find some charcoal.
Anyway, it was a fascinating experience. And it’s left me with a new favourite art medium.
Brontosmash: The Field Trip (the teaser)
February 13, 2018
This past weekend I was camping up the coast at Hearst San Simeon State Park, with my son, London, and Brian Engh.
We went to see the elephant seal colony at Piedras Blancas. It was my first time seeing elephant seals in the wild. Not having done any research in advance, I was expecting something like this:
In other words, a small number of elephant seals, not doing much, basically at binocular distance from the viewing area. Obviously we did get some of that, since I have a picture of it. But that was up the coast a bit, at the start of Boucher Trail near the Piedras Blancas lighthouse.
We spent most of our time at the main Piedras Blancas rookery, where just the southeastern half of the viewing area looked – and sounded – like this:
We also saw a lot of this (semi-groady iPhone-through-binocular shot by me):
and even some of this (much nicer photo courtesy of Brian Engh):
I’ll have a lot more to say about this real soon, including more video, but it’s late and I need sleep. Stay tuned!
Fighting apatosaur art #7: the world speaks!
October 22, 2015
I’d hoped that we’d see a flood of BRONTOSMASH-themed artwork, but that’s not quite happened. We’ve seen a trickle, though, and that’s still exciting. Here are the ones I know about. If anyone knows of more, please let me know and I will update this post.
First, in a comment on the post with my own awful attempts, Darius posted this sketch of a BROTOSMASH-themed intimidation display:
And in close-up:
Very elegant, and it’s nice to see an extension of our original hypothesis into other behaviours.
The next thing I saw was Mark Witton’s beautiful piece, described on his own site (in a post which coined the term BRONTOSMASH):
And in close-up:
I love the sense of bulk here — something of the elephant-seal extant analogue comes through — and the subdued colour scheme. Also, the Knight-style inclusion in the background of the individual in the swamp. (No, sauropods were not swamp-bound; but no doubt, like elephants, they spent at least some time in water.)
And finally (for now, at least) we have Matthew Inabinett’s piece, simply titled BRONTOSMASH:
I love the use of traditional materials here — yes, it still happens! — and I like the addition of the dorsal midline spike row to give us a full on TOBLERONE OF DOOM. (Also: the heads just look right. I wish I could do that. Maybe one day.)
Update (Monday 26 October)
Here is Oliver Demuth’s sketch, as pointed out by him in a comment.
Thanks, Oliver! Nice to see the ventral-on-dorsal combat style getting some love.
So that’s where we are, folks. Did I miss any? Is anyone working on new pieces on this theme? Post ’em in the comments!
Fighting apatosaur art #6: the ones that got away
September 30, 2015
Here’s the last post (at least for now) in the Fighting Apatosaur Art series — and we’re back to Brian Engh, who we started with.
Early in the process of putting together artwork to illustrate our apatosaur neck combat hypothesis, Brian tried out a whole bunch of outlandish concepts. Here are two that he showed us, but which were too speculative to push forward with. First, necks as big, floppy display structures:
As a piece of art, I really like this one: the boldness, the vivid contrasts, the alien quality of the animals. But as a palaeobiological hypothesis, it doesn’t really work: so much of the neck morphology in apatosaurs is to do with absorbing ventral forces that soft-tissue display structures down there don’t make a whole lot of sense.
Here’s the other one — which Brian titles “Apatosaur inflato-porcupine fish neck-bag”.
I particularly like the way the theropod being rolled around on the ground and repeatedly spiked. It’s no more than it deserves.
Does the idea of an inflatable neck make sense? I wouldn’t be at all surprised if there were sauropods that did something like this — plenty of extant animals inflate parts of their body for display purposes, after all — but I don’t think it would have been apatosaurs. Again, the characteristic features of the neck don’t seem well matched to this scenario.
Well, that’s all the apatosaur neck-combat art we have. If there’s to be a part 7 in this series, it will be made of artwork that you, dear readers, have contributed. Fire away!
Fighting apatosaur art #5: Mark Witton
September 28, 2015
If we accept that the distinctive ventral projections of the gigantic and ventrally displaced cervical ribs of apatosaurs were likely the base of some form of soft-tissue rugosity — such as keratinous horns like those of rhinos — then does it follow that those necks were used in combat as we suggested?
Maybe, maybe not. As scientists, we are always open to other hypotheses. We’re looking for the simplest, most parsimonious model — the one which best explains the facts.
That’s why we like Mark Witton’s “neck-velcro wall-climbing” hypothesis, as shown in this actual scientific life restoration.
As Mark explained to me, apatosaurs may have used their neck-hooks for more than passive clinging. They may also have been used for inching up the rock-face: first one side of the neck advancing and then the next, in the manner of the “pterygoid walking” that snakes use to progressively swallow large prey.
This is why it’s important to present early-stage work at conferences (and as preprints). Otherwise, you may never hear about important alternative hypotheses like this until after the paper is out and it’s too late to include them.
Sauropod Vertebra Picture of the Week 
