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!
Hey, Mike! Why haven’t you been blogging much lately?
October 14, 2020
Well, one reason is the utterly rancid “block editor” that WordPress has started imposing with increasing insistence on its poor users. If there is one thing that world really doesn’t need, it’s a completely new way of writing text. Seriously, WordPress, that was a solved problem in 1984. As Henry Spencer very nearly said back in the eighties, “thy creativity is better used in solving problems than in creating beautiful new impediments to productivity“.
But enough pointless whining: instead, check out this bad boy:
Taylor (in prep. for 2020: Figure V). NHMUK PV R5937, “The Archbishop”, cervical vertebra V (most anterior preserved cervical vertebra, probably C6), left side still encased in plaster. A. Reconstruction of right lateral view with neural spine, prezygapophysis, diapophysis, condyle, cotyle and cervical rib restored. The prezygapophysis from the succeeding vertebra that has adhered to this element is shown in red. B. Dorsal view with anterior to the right. C. Posterior view. D. Right lateral view. E. Anterior view. F. Ventral view with anterior to the right. Scale bar 20 cm.
Yes, it’s your friend and mine, The Archbishop! It’s a big titanosauriform sauropod excavated by F. W. H. Migeod for the British Museum (Natural History) back in 1930, from the same Tendaguru Formation that yielded the awesome Giraffatitan specimens in the Museum für Naturkunde Berlin.
Yes, I admit I have been working on the Archbishop for more than sixteen years, and that I gave a talk about it at SVPCA 2005, and that I failed utterly to get it done as part of the Paleo Project Challenge 2010, and that as early as 2011 I was in despair about ever finishing it, and that I promised to do it by SVPCA 2016 but didn’t.
But in 2018 I did something significant, which was to actually start writing the paper in public. Now anyone can follow the progress of the project — and it’s progressing. The manuscript currently runs to about fifty printed pages, although that length is inflated by twenty-odd beautiful illustrations — of which the “Cervical V” image above is just one. (Do click through to see it in all its glory.)
So, yeah. That’s the main reason I am not blogging much. Because I am writing the paper. Finally.
You! Shall not! Pass!
August 22, 2020
OK, technically this is MB.R.3822, a dorsal vertebra of Giraffatitan brancai formerly known as HMN Ar1, in posterior view, rendered from a 3D scan provided by Heinrich Mallison.
But you can’t tell me that when you look at that you don’t see Gandalf shouting at a balrog.
Long before Matt and others were CT-scanning sauropod vertebrae to understand their internal structure, Werner Janensch was doing it the old-fashioned way. I’ve been going through old photos that I took at the Museum für Naturkunde Berlin back in 2005, and I stumbled across this dorsal centrum:
Dorsal vertebra centum of ?Giraffatitan in ventral view, with anterior to top.
You can see a transverse crack running across it, and sure enough the front and back are actually broken apart. Here there are:
The same dorsal vertebral centrum of ?Giraffatitan, bisected transversely in two halves. Left: anterior half in posterior view; right: posterior half in anterior view. I had to balance the anterior half on my shoe to keep it oriented corrrectly for the photo.
This does a beautiful job of showing the large lateral foramina penetrating into the body of the centrum and ramifying further into the bone, leaving only a thin midline septum.
But students of the classics will recognise this bone immediately as the one that Janensch (1947:abb. 2) illustrated the posterior half of in his big pneumaticity paper:
It’s a very strange feeling, when browsing in a collection, to come across a vertebra that you know from the literature. As I’ve remarked to Matt, it’s a bit like running into, say, Cameron Diaz in the corner shop.
Reference
- Janensch, W. 1947. Pneumatizitat bei Wirbeln von Sauropoden
und anderen Saurischien. Palaeontographica, supplement
7:1-25.
The Nanoblock Brachiosaurus
May 2, 2020
My eldest son Dan went out to visit his girlfriend Beth, shortly before the Coronavirus crisis began, during her university placement in Toulouse. While they were there, they bought me this gift:
As you can see, it’s a Lego-like self-assembly kit; but as you can also see from the mug in the background, it’s tiny. As best I can make out, the blocks are half the length and width of Lego blocks, and about third the height. The whole model is about seven or eight inches (18-20 cm) from nose to tail.
Here’s a very quick walk-round, so you can appreciate the 3d shape.
I am properly impressed with this. It has the shape of the ribcage right, and the hips and shoulders, and the proportions are right so that it conveys with absolute conviction the quality of brachiosaurosity. It has a very posable neck that can be placed in a realistic life posture, and there are even hints of scapulae and ilia.
I made only one change from the instructions: I reoriented the forefoot so that we have a vertically oriented arcade of metacarpals rather than a plantigrade forefoot.
It was a very picky build. The instructions recommend using Nanoblock tweezers, sold separately, but I just used my big clumsy fingers, so that ribs and legs and things were constantly falling off. The process was rather like what this video shows, but much slower.
If you want one of your own, you can get it from Amazon UK or from Amazon US. I recommend it for serious sauropod lovers, but would be infuriating for children, and requires patience and precision to assemble.
Oh, and kit came with plenty of spare parts, in case you lose some of them: enough that Dan was able to make a juvenile with the leftovers.
Sauropod Vertebra Picture of the Week 