My Brachiosaurus talk for Dinosaur Journey is now on YouTube
October 20, 2021
My Oct. 13 National Fossil Day public lecture, “Lost Giants of the Jurassic”, for the Museums of Western Colorado – Dinosaur Journey is now up on their YouTube channel. First 48 minutes are talk, last 36 minutes are Q&A with audience, moderated by Dr. Julia McHugh. New stuff from the 2021 field season — about which I’ll have more to say in the future — starts at about the 37-minute mark. Hit the 44-minute mark (and this and this) to find out what to do with all of the unwanted bird necks that will be floating around at the upcoming holidays.
Finally, big thanks to Brian Engh for finding our brachiosaur and for letting me use so much of his art, to John Foster, Kaelen Kay, Tom Howells, Jessie Atterholt, Thierra Nalley, and Colton Snyder for such a fun field season this year, and to Julia McHugh for giving me the opportunity to yap about one of my favorite dinosaurs!
Matt Wedel will be yapping about Brachiosaurus. Again.
October 7, 2021
I have the honor of giving the National Fossil Day Virtual Lecture for The Museums of Western Colorado – Dinosaur Journey, next Wednesday, October 13, from 7:00 to 8:00 PM, Mountain Daylight Time. The title of my talk is “Lost Giants of the Jurassic” but it’s mostly going to be about Brachiosaurus. And since I have a whole hour to fill, I’m gonna kitchen-sink this sucker and put in all the good stuff, even more than last time. The talk is virtual (via Zoom) and free, and you can register at this link.
The photo up top is from this July. That’s John Foster (standing) and me (crouching) with the complete right humerus of Brachiosaurus that we got out of the ground in 2019; that story is here. The humerus is in the prep lab at the Utah Field House of Natural History State Park Museum in Vernal, and if you go there, you can peer through the tall glass windows between the museum’s central atrium and the prep lab and see it for yourself.
If you’ve forgotten what a humerus like that looks like in context, here’s the mounted Brachiosaurus skeleton at the North American Museum of Ancient Life with my research student, Kaelen Kay, for scale. Kaelen is 5’8″ (173cm) and as you can see, she can just get her hand on the animal’s elbow. The humerus–in this case, a cast of the right humerus from the Brachiosaurus altithorax holotype–is the next bone up the line. Kaelen came out with us this summer and helped dig up some more of our brachiosaur–more on that story in the near future.
Want more Brachiosaurus? Tune in next week. Here’s that registration link again. I hope to see you there!
How big was the Archbishop?
June 2, 2021
Various Internet rumours have suggested that the Archbishop is a super-giant sauropod one third larger than the mounted Giraffatitan specimen MB.R.2181 (formerly HMN SII). This is incorrect.
Migeod’s assessment of the size of the animal was based on the vertebrae: “The [neck] vertebrae found give a 20-foot [6.10 m] length […] The length of the back including the sacral region was about 15 feet [4.57 m]. The eight or nine caudal vertebrae cover about 6 feet [1.83 m]” (Migeod 1931a:90). This gives the total preserved length of the skeleton as 41 feet (12.50 m). By comparison, Janensch (1950b:102) gives lengths of portions of the mounted skeleton of MB.R.2181 as 8.78m (neck), 3.92m (torso) and 1.07m (sacrum) for a torso-plus-sacrum length of 4.99m. On this basis, the preserved neck of NHMUK PV R5937 is only 69% as long as that of MB.R.2181, but since the first four vertebrae were missing and omitted from Migeod’s measurement, this factor cannot be taken at face value. More informative is the torso-plus-sacrum length, which in NHMUK PV R5937 is 92% the length of MB.R.2181.
This is consonant with measurements of individual elements, which compare as follows:
Table 4. Comparative measurements of Archbishop and Giraffatitan elements
| Element | Measurement (cm) | Archbishop | Giraffatitan | Ratio |
|---|---|---|---|---|
| Torso plus sacrum | total length | 457 | 499 | 0.916 |
| C10 (mC4) | centrum length | 99 | 100 | 0.990 |
| C11 (mC3) | centrum length | 104 | 100[1] | 1.040 |
| D4 (mD3) | centrum length | 27 | 36 | 0.750 |
| Longest rib | length over curve | 235 | 263 | 0.894 |
| Left scapulocoracoid | length over curve | 221 | 238[2] | 0.929 |
| Right humerus | length | 146 | 213 | 0.685 |
| Right humerus | width | 51 | 59 | 0.864 |
| Right ilium | length | 98 | 123[3] | 0.797 |
| Right ilium | height | 79 | 96[4] | 0.823 |
| Femur | length | 122 | 196[5] | 0.622 |
| Average | 0.846 |
Archbishop measurements taken from Migeod (1931a) and converted from imperial; Giraffatitan measurements are for MB.R.2181 except where noted, and are taken from Janensch (1950a:44) and Janensch (1961).
Notes.
[1] Janensch (1950a) did not report a total centrum length for C11, as its condyle had not been removed from the cotyle of C10; but since the length of its centrum omitting the condyle was, at 87 cm, identical to that of C10, it is reasonable to estimate its total length as also equal to that of C10.
[2] Janensch (1961:181) did not include measurements for the right scapula of MB.R.2181, which is incorporated into the mounted skeleton, but does give the proximodistal length of its right coracoid as 45 cm. Using the 193 cm length given for the similarly sized scapula Sa 9, we can deduce a reasonable total estimate of 238 cm for the scapulocoracoid.
[3] Estimated by Janensch (1950b:99) based on cross-scaling from the fibula and ilium of Find J from the Upper Saurian Marl.
[4] This is the measurement provided by Janensch (1961:199) for the ilium Ma 2, which is incorporated into the mounted skeleton, and which Janensch (1950b:99) considered to match MB.R.2181 very precisely.
[5] Based on a restoration of the midshaft which Janench (1950b:99) calcuated based on other finds.
Individual lines of this table should each be treated with caution: Migeod’s measurements may have been unreliable, and in any case are underspecified: for example, we do not know whether, when he gave a vertebra’s length, he included overhanging prezygapophyses or the condyle. Similarly, we know that Migeod (1931:96) wrote that a rib “was as much as 92.5 inches long”, but we do not know for certain that, like Janensch, he measured the length over the curve rather than the straight-line distance between the ends. And when Migeod says that the ilium “measured 38.5 by 31 inches” we do not know that the height was measured “at the public process”, as Janensch (1961:199) specified.
With those caveats in place, nevertheless, a picture emerges of a sauropod somewhat smaller than MB.R.2181, though by no means negligible. On average, the measurements come out about 15% smaller than those of Giraffatitan.
But this average conceals a great deal of variation. The cervical vertebrae are comparable in length to those of MB.R.2181 (The total of 203 cm for C10 and C11 in the Archbishop, only 1.5% longer than 200 cm for MB.R.2181, is a difference well within the margin of measurement error). The Archbishop’s scapulocoracoid may have been 93% as long as in MB.R.2181. But the limb bones are signficantly shorter (87% for the humerus and a scarcely credible 62% for the femur), and the humeri at least bseem to be have been proportionally more robust in the Archbishop: only 2.86 times as long as wide, whereas the ratio is 3.61 in MB.R.2181. If Migeod’s measurements can be trusted, we have here an animal whose neck is as long as that of Giraffatitan, but whose limbs are noticably shorter. These proportions corroborate the hypothesis that the Archbishop is not a specimen of Giraffatitan.
Amazing things are out there waiting to be noticed
March 22, 2021
It is said that, some time around 1590 AD, Galileo Galilei dropped two spheres of different masses from the Leaning Tower of Pisa[1], thereby demonstrating that they fell at the same rate. This was a big deal because it contradicted Aristotle’s theory of gravity, in which objects are supposed to fall at a speed proportional to their mass.
Aristotle lived from 384–322 BC, which means his observably incorrect theory had been scientific orthodoxy for more than 1,900 years before being overturned[2].
How did this happen? For nearly two millennia, every scientist had it in his power to hold a little stone in one hand and a rock in the other, drop them both, and see with his own eyes that they fell at the same speed. Aristotle’s theory was obviously wrong, yet that obviously wrong theory remained orthodox for eighty generations.
My take is that it happened because people — even scientists — have a strong tendency to trust respected predecessors, and not even to look to see whether their observations and theories are correct. I am guessing that in that 1,900 years, plenty of scientists did indeed do the stone-and-rock experiment, but discounted their own observations because they had too much respect for Aristotle.
But even truly great scientists can be wrong.
Now, here is the same story, told on a much much smaller scale.
Well into the 2010s, it was well known that in sauropods, caudal vertebrae past the first handful are pneumatized only in diplodocines and in saltasaurine titanosaurs. As a bright young sauropod researcher, for example, I knew this from the codings in important and respected phylogenetic analysis such as those of Wilson (2002) and Upchurch et al. (2004).
Until the day I visited the Museum für Naturkunde Berlin and actually, you know, looked at the big mounted Giraffatitan skeleton in the atrium. And this is what I saw:
That’s caudal vertebrae 24–26 in left lateral view, and you could not wish to see a nicer, clearer pneumatic feature than the double foramen in caudal 25.
That observation led directly to Matt’s and my 2013 paper on caudal pneumaticity in Giraffatitan and Apatosaurus (Wedel and Taylor 2013) and clued us into how much more common pneumatic hiatuses are then we’d realised. It also birthed the notion of “cryptic diverticula” — those whose traces are not directly recorded in the fossils, but whose presence can be inferred by traces on other vertebrae. And that led to our most recent paper on pneumatic variation in sauropods (Taylor and Wedel 2021) — from which you might recognise the photo above, since a cleaned-up version of it appears there as Figure 5.
The moral
Just because “everyone knows” something is true, it doesn’t necessarily mean that it actually is true. Verify. Use your own eyes. Even Aristotle can be wrong about gravity. Even Jeff Wilson and Paul Upchurch can be wrong about caudal pneumaticity in non-diplodocines. That shouldn’t in any way undermine the rightly excellent reputations they have built. But we sometimes need to look past reputations, however well earned, to see what’s right in front of us.
Go and look at fossils. Does what you see contradict what “everyone knows”? Good! You’ve discovered something!
References
- Taylor, Michael P., and Mathew J. Wedel. 2021. Why is vertebral pneumaticity in sauropod dinosaurs so variable? (version 5) Qeios 1G6J3Q.5. doi:10.32388/1G6J3Q.5
- Upchurch, Paul, Paul M. Barrett and Peter Dodson. 2004. Sauropoda. pp. 259–322 in D. B. Weishampel, P. Dodson and H. Osmólska (eds.), The Dinosauria, 2nd edition. University of California Press, Berkeley and Los Angeles. 861 pp.
- Wedel, Mathew J., and Michael P. Taylor 2013. Caudal pneumaticity and pneumatic hiatuses in the sauropod dinosaurs Giraffatitan and Apatosaurus. PLOS ONE 8(10):e78213. 14 pages. doi: 10.1371/journal.pone.0078213
- Wilson, Jeffrey A. 2002. Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnean Society 136:217–276.
Notes
1. There is some skepticism about whether Galileo’s experiment really took place, or was merely a thought experiment. But since the experiment was described by Galileo’s pupil Vincenzo Viviani in a biography written in 1654, I am inclined to trust the contemporary account ahead of the unfounded scepticism of moderns. Also, Viviani’s wording, translated as “Galileo showed this by repeated experiments made from the height of the Leaning Tower of Pisa in the presence of other professors and all the students” reads like a documentary account rather than a romanticization. And a thought experiment, with no observable result, would not have demonstrated anything.
2. Earlier experiments had similarly shown that Aristotle’s gravitational theory was wrong, including in the works of John Philoponus in the sixth century — but Aristotle’s orthodoxy nevertheless survived until Galileo.
Equatorial Minnesota on Alamosaurus
February 21, 2021
Figure 3. BIBE 45854, articulated series of nine mid and posterior cervical vertebrae of a large, osteologically mature Alamosaurus sanjuanensis. Series is estimated to represent the sixth to fourteenth cervical vertebrae. A, composite photo-mosaic of the cervical series in right lateral view; identification of each vertebra indicated by C6 to C14, respectively. B, line drawing based on the photo-mosaic in A. C, line drawing in B with labels shown and vertebral fossae indicated by solid grey fill; cross-hatching represents broken bone surfaces and reconstructive material. Abbreviations: C, cervical vertebra; cdf, centrodiapophyseal fossa; clf, centrum lateral fossa; pocdf, postzygapophyseal centrodiapophyseal fossa; prcdf, prezygapophyseal centrodiapophyseal fossa; prcdf1, dorsal prezygapophyseal centrodiapophyseal fossa; prcdf2, ventral prezygapophyseal centrodiapophyseal fossa; sdf, spinodiapophyseal fossa; spof, spinopostzygapophyseal fossa; sprf, spinoprezygapophyseal fossa. (Tykoski and Fiorillo 2016)
Have you been reading Justin Tweet’s series, “Your Friends the Titanosaurs“, at his awesomely-named blog, Equatorial Minnesota? If not, get on it. He’s been running the series since June, 2018, so this notice is only somewhat grotesquely overdue. The latest installment, on Alamosaurus from Texas and Mexico, is phenomenal. I have never seen another summary or review that pulled together so much of the relevant literature and explained it all so well. Seriously, that blog post deserves to be a review paper; it could be submitted pretty much as-is, although it would be even better with his two other Alamosaurus posts integrated (this one, and this one). It’s great work, is what I’m saying, and it needs to be acknowledged.
In particular, I was struck by the note by Anonymous in 1941 on the discovery of a cervical vertebra 1.2 meters long. I’d never heard of that ref, and I’ve never seen that vert, but at 120cm it would be in the top 7 longest cervical vertebrae on the planet (see the latest version of the list in this post), narrowly beating out the 118-cm cervical of Puertasaurus. In fairness, the preserved cervical of Puertasaurus is probably a posterior one, and more anterior cervicals might have been longer. Then again, in the big Alamosaurus neck the longest verts are pretty darned posterior, so…we need more Puertasaurus.
EDIT a few hours later: Thanks to the kind offices of Justin Tweet, I’ve now seen Anonymous (1941), and the exact wording is, “A single vertebra, or neck joint bone, is three feet across, only two inches less than four feet long, and in its present fossilized state weighs 600 pounds.” ‘Two inches less than four feet long’ is 46 inches or a hair under 117cm, which puts the supposed giant cervical just behind Puertasaurus after all, but still firmly in the top 10. And depending on how one interprets the passage in Anonymous (1941), it might not have been any bigger than BIBE 45854–see this comment for details.
Big cervical showdown. From the top left: BYU 9024, originally referred to Supersaurus but more likely representing a giant Barosaurus (137cm); the single available cervical of Puertasaurus (118cm); a world-record giraffe neck (2.4m); Alamosaurus referred cervical series BIBE 45854, longest centra are ~81cm; Sauroposeidon holotype OMNH 53062, longest centrum is 125cm. This image makes it very clear that whatever Sauroposeidon was doing, it was a way different thing from Alamosaurus.
Crucially, the longest vertebrae in the BIBE 45854 series are about 80 or 81 cm long, which means that a 1.2-meter cervical would be half again as large. That is a pretty staggering thought, and that individual of Alamosaurus–assuming it was the same taxon as BIBE 45854, and not some other, longer-necked critter–would definitely be a contender for the largest sauropod of all time.
Illustrations here are of the big Alamosaurus cervical series from Big Bend, which was comprehensively described by Ron Tykoski and Tony Fiorillo in 2016, and which we have covered in these previous posts:
- How big was Alamosaurus?
- Going to see the big mounted Alamosaurus next week
- BIBE 45854, the giant Alamosaurus cervical series from Big Bend, Texas
References
- Anonymous. 1941. Find dinosaur neck bone nearly four feet long. The Science News-Letter 39(1):6–7.
- Tykoski, R.S. and Fiorillo, A.R. 2016. An articulated cervical series of Alamosaurus sanjuanensis Gilmore, 1922 (Dinosauria, Sauropoda) from Texas: new perspective on the relationships of North America’s last giant sauropod. Journal of Systematic Palaeontology 15(5):339-364.
Can we distinguish taphonomic distortion and (paleo)pathology from normal biological variation?
February 12, 2021
Taylor 2015: Figure 8. Cervical vertebrae 4 (left) and 6 (right) of Giraffatitan brancai lectotype MB.R.2180 (previously HMN SI), in posterior view. Note the dramatically different aspect ratios of their cotyles, indicating that extensive and unpredictable crushing has taken place. Photographs by author.
Here are cervicals 4 and 8 from MB.R.2180, the big mounted Giraffatitan in Berlin. Even though this is one of the better sauropod necks in the world, the vertebrae have enough taphonomic distortion that trying to determine what neutral, uncrushed shape they started from is not easy.
Wedel and Taylor 2013b: Figure 3. The caudal vertebrae of ostriches are highly pneumatic. This mid-caudal vertebra of an ostrich (Struthio camelus), LACM Bj342, is shown in dorsal view (top), anterior, left lateral, and posterior views (middle, left to right), and ventral view (bottom). The vertebra is approximately 5cm wide across the transverse processes. Note the pneumatic foramina on the dorsal, ventral, and lateral sides of the vertebra.
Here’s one of the free caudal vertebrae of an ostrich, Struthio camelus, LACM Ornithology Bj342. It’s a bit asymmetric–the two halves of the neural spine are aimed in slightly different directions, and one transverse process is angled just slightly differently than the other–but the asymmetry is pretty subtle and the rest of the vertebral column looks normal, so I don’t think this rises to the level of pathology. It looks like the kind of minor variation that is present in all kinds of animals, especially large-bodied ones.
This is a dorsal vertebra of a rhea, Rhea americana, LACM Ornithology 97479, in posteroventral view. Ink pen for scale. I took this photo to document the pneumatic foramina and related bone remodeling on the dorsal roof of the neural canal, but I’m showing it here because in technical terms this vert is horked. It’s not subtly asymmetric, it’s grossly so, with virtually every feature–the postzygapophyses, diapophyses, parapophyses, and even the posterior articular surface of the centrum–showing fairly pronounced differences from left to right.
That rhea dorsal looks pretty bad for dry bone from a recently-dead extant animal, but if it was from the Morrison Formation it would be phenomenal. If I found a sauropod vertebra that looked that good, I’d think, “Hey, this thing’s in pretty good shape! Only a little distorted.” The roughed-up surface of the right transverse process might give me pause, and I’d want to take a close look at those postzygs, but most of this asymmetry is consistent with what I’d expect from taphonomic distortion.
Which brings me to my titular question, which I am asking out of genuine ignorance and not in a rhetorical or leading way: can we tell these things apart? And if so, with what degree of confidence? I know there has been a lot of work on 3D retrodeformation over the past decade and a half at least, but I don’t know whether this specific question has been addressed.
Corollary question: up above I wrote, “It looks like the kind of minor variation that is present in all kinds of animals, especially large-bodied ones”. My anecdotal experience is that the vertebrae of large extant animals tend to be more asymmetric than those of small extant animals, but I don’t know if that’s a real biological phenomenon–bone is bone but big animals have larger forces working on their skeletons, and they typically live longer, giving the skeleton more time to respond to those forces–OR if the asymmetry is the same in large and small animals and it’s just easier to see in the big ones.
If either of those questions has been addressed, I’d be grateful for pointers in the comments, and thanks in advance. If one or both have not been addressed, I think they’re interesting but Mike and I have plenty of other things to be getting on with and we’re not planning to work on either one, hence the “Hey, you! Want a project?” tag.
References
- Taylor, Michael P. 2015. Almost all known sauropod necks are incomplete and distorted. PeerJ Preprints 3:e1767. doi:10.7287/peerj.preprints.1418v1
- Wedel, Mathew J., and Michael P. Taylor. 2013. Caudal pneumaticity and pneumatic hiatuses in the sauropod dinosaurs Giraffatitan and Apatosaurus.PLOS ONE 8(10):e78213. 14 pages. doi:10.1371/journal.pone.0078213 [PDF]
My favorite t-shirt
February 1, 2021
If you’ve been around SV-POW! for long, you’ve seen me in this shirt:
“Retro Brontosaurus Dinosaur T-shirt” by Dinosaur Tees, modeled by Matt Wedel, cast right forelimb of Brachiosaurus for scale.
I found it on Amazon. Well, actually the first one I found was this rather dapper plesiosaur:
One of the things I like best about the recent movies in Legendary Pictures’ MonsterVerse — Godzilla (2014), Kong: Skull Island, Godzilla: King of the Monsters, and the upcoming Godzilla vs Kong — is Monarch, the shadowy organization tasked with finding and studying giant monsters. By the time of King of the Monsters, Monarch is basically SHIELD, with bases scattered around the globe and a giant flying carrier-aircraft, the USS Argo.
I prefer the scrappier, always-on-the-verge-of-being-shut-down Monarch from the 1973-set Kong: Skull Island. And, as you’ve probably guessed by now, I was instantly taken with that plesiosaur t-shirt because in my headcanon it was the official garb of Monarch’s Loch Ness division in the 1970s. I had to go with the sauropod version, though, for obvious reasons — maybe Monarch has a Mokele-mbembe division (not so far out since old M-M shows up as a dot on a map in King of the Monsters).
I have zero stake in Dinosaur Tees, mind. I just dig their retro dinosaur shirts. Find them here.
And as for Monarch — at least in its early incarnation, as a ragtag group of underfunded folks from wildly differing backgrounds that goes to remote places to search for monsters — I flatter myself that I have a not-entirely-different job.
What a dream I had!
January 31, 2021
Oh, hey, so you know how the most tedious thing you can ever hear is someone recounting one of their dreams? I want to tell you about a dream I had last night.
Brian Curtice’s grandfather was in a position of authority to express condemnation of a group of people who had lost the electronic archives of the Daily Telegraph, but declined to do so. So I became part of a woke mob that went to Curtice’s house to express our displeasure to him. I got distracted by an outbuilding when we arrived, went in, and found that it contained the Sonorosaurus type material, which for some reason included two really nice scapulocoracoids. At that point my Index Data colleague Wayne (also part of the woke mob) wandered in and I expressed to him that I was having second thoughts about this whole protest and that my first concern now was protecting the holotype against the more indiscriminate members of the mob. But I kept thinking to myself “Why is this material even here? If anything, it should be in an outbuilding at Kevin Ratkevic’s house.” Then Wayne and I spotted a bunch of computer monitors running software that Curtice had written earlier in his life, and it became apparent that he was the creator of a Commodore 64 adventure game called Pilgrim for which the publishers had ripped off an 8×8 old-English-style character set that I had used in a game I’d published with them.
Ratkevic (1988:figure 4).Lower hind limb including tibia, fibula, and nearly complete left pes of Sonorasaurus thompsoni holotype ASDM 500. Elements found associated but not articulated. Entire assembled length 137 cm. Photo by Jeanne Broome.
So. I never remember dreams in this kind of detail. The fact that I did on this on occasion is strange to me — but then, these are strange times. A quick run-down of what is and isn’t true:
- So far as I know, the Daily Telegraph archives have not been lost.
- Brian Curtice is a sauropod palaeontologist, maybe best known for his work reassessing Jensen’s Dry Mesa sauropods (e.g. Curtice et al. 1996, Curtice and Stadtman 2001); I have no idea if he has a grandfather and whether he has any involvement with archives.
- I do not know where Brian lives, or whether he has any fossils at his house. I highly doubt he has holotypes.
- The holotype of Sonorasaurus does not include any shoulder-girdle material, but it was indeed described by Ratkevich (1988) — but Ron, not Kevin.
- There really was a Commodore 64 adventure game called Pilgrim, published by CRL, and they really did re-use — without my permission — the character set I had defined in The Causes of Chaos, which I had published with them not long before.
- But Pilgrim was by Rod Pike, and I very highly doubt that Brian Curtice, even if he was a C64 programmer in the early-mid 90s, ever published any games with a UK-based software house.
Matt’s response when I told him about this dream:
Just got to the scapulocoracoids and LLOL
“my first concern now was protecting the holotype against the more indiscriminate members of the mob.” LLOL x infinity
Well, I gotta tell you, that was a ride.
Jurassic-Park-style, through your hindbrain.
It had everything!
Woke mobs, holotypes, old school adventure games, intellectual property (at the start and at the end)lost archivesthis is so specific in so many weirdly-specialized areas that whole schools may spring up to interpret it. You might accidentally found a new religion.
All right, folks: interpret for me!
References
- Curtice, Brian D., Kenneth L. Stadtman and Linda J. Curtice. 1996. A reassessment of Ultrasauros macintoshi (Jensen, 1985). The continental Jurassic (M. Morales, ed.): Museum of Northern Arizona Bulletin 60:87–95.
- Curtice, Brian D. and Kenneth L. Stadtman. 2001. The demise of Dystylosaurus edwini and a revision of Supersaurus vivianae. Western Association of Vertebrate Paleontologists and Mesa Southwest Museum and Southwest Paleontologists Symposium, Bulletin 8:33–40.
- Ratkevich, Ron. 1998. New Cretaceous brachiosaurid dinosaur, Sonorasaurus thompsoni gen et sp. nov, from Arizona. Journal of the Arizona-Nevada Academy of Science 31:71–82.
We’ve noted many times over the years how inconsistent pneumatic features are in sauropod vertebra. Fossae and formamina vary between individuals of the same species, and along the spinal column, and even between the sides of individual vertebrae. Here’s an example that we touched on in Wedel and Taylor (2013), but which is seen in all its glory here:
Taylor and Wedel (2021: Figure 5). Giraffatitan brancai tail MB.R.5000, part of the mounted skeleton at the Museum für Naturkunde Berlin. Caudal vertebrae 24–26 in left lateral view. While caudal 26 has no pneumatic features, caudal 25 has two distinct pneumatic fossae, likely excavated around two distinct vascular foramina carrying an artery and a vein. Caudal 24 is more shallowly excavated than 25, but may also exhibit two separate fossae.
But bone is usually the least variable material in the vertebrate body. Muscles vary more, nerves more again, and blood vessels most of all. So why are the vertebrae of sauropods so much more variable than other bones?
Our new paper, published today (Taylor and Wedel 2021) proposes an answer! Please read it for the details, but here’s the summary:
- Early in ontogenly, the blood supply to vertebrae comes from arteries that initially served the spinal cord, penetrating the bone of the neural canal.
- Later in ontegeny, additional arteries penetrate the centra, leaving vascular foramina (small holes carrying blood vessels).
- This hand-off does not always run to completion, due to the variability of blood vessels.
- In extant birds, when pneumatic diverticula enter the bone they do so via vascular foramina, alongside blood vessels.
- The same was probaby true in sauropods.
- So in vertebrae that got all their blood supply from vascular foramina in the neural canal, diverticula were unable to enter the centra from the outside.
- So those centra were never pneumatized from the outside, and no externally visible pneumatic cavities were formed.
Somehow that pretty straightforward argument ended up running to eleven pages. I guess that’s what you get when you reference your thoughts thoroughly, illustrate them in detail, and discuss the implications. But the heart of the paper is that little bullet-list.
Taylor and Wedel (2021: Figure 6). Domestic duck Anas platyrhynchos, dorsal vertebrae 2–7 in left lateral view. Note that the two anteriormost vertebrae (D2 and D3) each have a shallow pneumatic fossa penetrated by numerous small foramina.
(What is the relevance of these duck dorsals? You will need to read the discussion in the paper to find out!)
Our choice of publication venue
The world moves fast. It’s strange to think that only eleven years ago my Brachiosaurus revision (Taylor 2009) was in the Journal of Vertebrate Palaeontology, a journal that now feels very retro. Since then, Matt and I have both published several times in PeerJ, which we love. More recently, we’ve been posting preprints of our papers — and indeed I have three papers stalled in peer-review revisions that are all available as preprints (two Taylor and Wedels and a single sole-authored one). But this time we’re pushing on even further into the Shiny Digital Future.
We’ve published at Qeios. (It’s pronounced “chaos”, but the site doesn’t tell you that; I discovered it on Twitter.) If you’ve not heard of it — I was only very vaguely aware of it myself until this evening — it runs on the same model as the better known F1000 Research, with this very important difference: it’s free. Also, it looks rather slicker.
That model is: publish first, then filter. This is the opposite of the traditional scholarly publishing flow where you filter first — by peer reviewers erecting a series of obstacles to getting your work out — and only after negotiating that course to do get to see your work published. At Qeios, you go right ahead and publish: it’s available right off the bat, but clearly marked as awaiting peer-review:
And then it undergoes review. Who reviews it? Anyone! Ideally, of course, people with some expertise in the relevant fields. We can then post any number of revised versions in response to the reviews — each revision having its own DOI and being fixed and permanent.
How will this work out? We don’t know. It is, in part, an experiment. What will make it work — what will impute credibility to our paper — is good, solid reviews. So if you have any relevant expertise, we do invite you to get over there and write a review.
And finally …
Matt noted that I first sent him the link to the Qeios site at 7:44 pm my time. I think that was the first time he’d heard of it. He and I had plenty of back and forth on where to publish this paper before I pushed on and did it at Qeios. And I tweeted that our paper was available for review at 8:44 — one hour exactly after Matt learned that the venue existed. Now here we are at 12:04 my time, three hours and 20 minutes later, and it’s already been viewed 126 times and downloaded 60 times. I think that’s pretty awesome.
References
- Taylor, Michael P. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806. [PDF]
- Taylor, Michael P., and Mathew J. Wedel. 2021. Why is vertebral pneumaticity in sauropod dinosaurs so variable? Qeios 1G6J3Q. doi: 10.32388/1G6J3Q [PDF]
- Wedel, Mathew J., and Michael P. Taylor 2013b. Caudal pneumaticity and pneumatic hiatuses in the sauropod dinosaurs Giraffatitan and Apatosaurus. PLOS ONE 8(10):e78213. 14 pages. doi: 10.1371/journal.pone.0078213 [PDF]
Accidental anaglyphs
October 16, 2020
Everyone knows that the very first thing you should do to improve your specimen photography is to use a tripod: it eliminates hand-shake and gives you much crisper photos. In most respects, my photographs have got much, much better since I’ve been habitually using a tripod.
But it has meant I’ve not been able to benefit from happy accidents like the one that gave me this 3D anaglyph of the Archbishop‘s Cervical S in dorsal view:
(Do you have red-cyan glasses? Yes? Good! You will be able to appreciate all the delicious morphological information in this photo. No? Go and order some right now — they cost literally a dollar.)
The reason I was able to make this very useful image is because back in the old pre-tripod days I would sometimes accidentally move a little bit between taking two more-or-less identical photographs. Here are the two images that I was able to composite into the anaglyph above:
Each of them is pretty uninformative alone: who can tell one nondescript area of brown bone from another? But when combined, they are extraordinarily more informative. If you don’t have 3D glasses then (A) get some! and (B) you can get some idea of how helpful the 3D information is from the crude wigglegram below, which simply switches back and forth between the two images.
And I can’t overstate how enormously helpful I have found these accidentally sourced anaglyphs as I write the descriptive part of the Archbishop manuscript. Even at this level of crudity, they have shown me several important points of morphology that I would certainly have missed if I’d been working only from my orthogonal-view photos, and saved me from more than one misinterpretation.
The moral is twofold:
- When taking specimen photographs, use a tripod — but deliberately get some pairs of shots where the camera is moved to the side by about 7 cm (the distance between the pupils in an average human).
- If you don’t have any red-cyan glasses, get some!
