A bunch of stuff, loosely organized by theme.

Media

First up, I need to thank Brian Switek, who invited me to comment on Patagotitan for his piece at Smithsonian. I think he did a great job on that, arguably the best of any of the first-day major media outlet pieces. And it didn’t go unnoticed – his article was referenced at both the Washington Post and NPR (and possibly other outlets, those are the two I know of right now). I don’t think my quotes got around because they’re particularly eloquent, BTW, but rather because reporters tend to like point-counterpoint, and I was apparently the most visible counterpoint. They probably would have done the same if I’d been talking complete nonsense (which, to be fair, some people may think I was).

Paleobiology vs Records

The most commonly reproduced quote of mine is this one, originally from Brian’s piece:

I think it would be more accurate to say that Argentinosaurus, Puertasaurus and Patagotitan are so similar in size that it is impossible for now to say which one was the largest.

That may seem at odds with the, “Well, actually…[pushes glasses up nose]…Argentinosaurus was still biggest” tack I’ve taken both in my post yesterday and on Facebook. So let me elaborate a little.

There is a minor, boring point, which is that when I gave Brian that quote, I’d seen the Patagotitan paper, but not the Electronic Supplementary Materials (ESM), so I knew that Patagotitan was about the same size as the other two (and had known for a while), but I hadn’t had a chance to actually run the numbers.

The much more interesting point is that the size differences between Argentinosaurus, Puertasaurus, and Patagotitan are astonishingly small. The difference between a 2.5m femur and a 2.4m one is negligible, ditto for vertebrae with centra 59cm and 60cm in diameter. OMNH 1331, the biggest centrum bit from the giant Oklahoma apatosaur, had an intact max diameter of 49cm, making it 26% larger in linear terms than the next-largest apatosaur. The centra of these giant South American titanosaurs are more than 20% bigger yet than OMNH 1331, just in linear terms. That’s crazy.

It’s also crazy that these three in particular – Argentinosaurus, Puertasaurus, and Patagotitan – are so similar in size. Dinosaur developmental programs were ‘messy’ compared to those of mammals, both in having weird timings for things like onset of reproduction, and in varying a lot among closely related taxa. Furthermore, sauropod population dynamics should have been highly skewed toward juveniles and subadults. So is the near-equality in size among Argentinosaurus, Puertasaurus, and Patagotitan just a coincidence, or does it mean that something weird was going on? There’s really no third option. I mean, even if some kind of internal (biomechanical or physiological) or external (ecological, food or predation) constraint forced those three to the same adult body size, it’s weird then that we’re finding only or at least mostly near-max-size adults. (If the available specimens of these three aren’t near-max-size, then any hypothesis that they’re forced to the same size by constraints is out the window, and we’re back to coincidence.)

BUT

With all that said, the title of “world’s largest dinosaur” is not handed out for effort expended, number of specimens collected, skeletal completeness, ontogenetic speculation, or anything other than “the dinosaur with the largest measured elements”. And that is currently Argentinosaurus. So although for any kind of paleobiological consideration we can currently consider Argentinosaurus, Puertasaurus, and Patagotitan to all be about the same size – and Alamosaurus, Paralititan, Notocolossus, and probably others I’ve forgotten should be in this conversation – anyone wanting to dethrone Argentinosaurus needs to actually show up with bigger elements.

So, if you’re interested in paleobiology, it’s fascinating and frankly kind of unnerving that so many of these giant titanosaurs were within a hand-span of each other in terms of size. Patagotitan is one more on the pile – and, as I said yesterday, exciting because it’s so complete.

But if you want to know who holds the crown, it’s still Argentinosaurus.

Humeri

In a comment on the last post, Andrea Cau made an excellent point that I am just going to copy here entire:

Even Paralititan stromeri humerus is apparently larger than Patagotitan humerus (169 cm vs 167.5 cm). I know humerus length alone is bad proxy of body size, but at least this shows that even in that bone Patagotitan is just another big titanosaur among a well known gang of titans, not a supersized one.

That made me want to start a list of the longest sauropod humeri. Here goes – if I missed anyone or put down a figure incorrectly, I’m sure you’ll let me know in the comments.

  • Giraffatitan: 213cm
  • Brachiosaurus: 203cm
  • Ruyangosaurus: 190cm (estimated from 135cm partial)
  • Turiasaurus: 179cm
  • Notocolossus: 176cm
  • Paralititan: 169cm
  • Patagotitan: 167.5cm
  • Dreadnoughtus: 160cm
  • Futlognkosaurus: 156cm

Admittedly the Patagotitan humerus is from a paratype and not from the largest individual, but that is true for some others on the list, including Giraffatitan. And we have no humeri from Argentinosaurus, Puertasaurus, and some other giants.

Dorsal Vertebrae

A couple of further thoughts on how the dorsal vertebrae of Patagotitan compare to those of Argentinosaurus. First, now that I’ve had some time to think about it, I have a hard time seeing how the dorsal polygon method used by Carballido et al. in the Patagotitan paper has any biological meaning. In their example figure, the polygon around the Puertasaurus vertebra is mostly full of bone, and the one around Patagotitan has a lot of empty space. It’s easy to imagine an alternative metric, like “area of the minimum polygon actually filled by bone”, that would lead to a different ‘winner’. But that wouldn’t mean much, either.

Something that probably does have a real and important biomechanical meaning is the surface area of the articular face of the centrum, because that’s the area of bone that has to bear the compressive load, which is directly related to the animal’s mass. The biggest Patagotitan centrum is that of MPEF-PV 3400/5, which is at least a local maximum since has smaller centra both ahead and behind. The posterior face measures 59cm wide by 42.5cm tall. Abstracted as an ellipse, which may not be perfectly accurate, those measurements give a surface area of (pi)(29.5)(21.25)=1970 cm^2. For Argentinosaurus, the largest complete centrum has a posterior face measuring 60cm wide by 47cm tall (Bonaparte and Coria 1993: p. 5), giving an elliptical surface area of (pi)(30)(23.5)=2210 cm^2. (I’d use hi-res images of the centra to measure the actual surface areas if I could, but AFAIK those images either don’t exist or at least have not yet been made public, for either taxon.) So although the Argentinosaurus dorsal seems like it is only a bit bigger in linear terms, it’s 12% larger in surface area, and that might actually be a meaningful difference.

Cervical Vertebrae

One thing I haven’t commented on yet – Patagotitan is the newest member of the “world’s longest vertebrae” club. The longest Patagotitan cervical, MPEF-PV 3400/3, is listed in the ESM as having a centrum length of 120cm, but it’s also listed as incomplete. In the skeletal recon in the paper, the centrum is colored in as present, but the neural spine is missing. So is the centrum complete in terms of length? I don’t think it’s clear right now.

Anyway, here’s the current rundown of the longest cervical centra of sauropods (and therefore, the longest vertebrae among animals):

  • BYU 9024, possibly referable to Supersaurus or Barosaurus: 137cm
  • Price River 2 titanosauriform: 129cm
  • OMNH 53062, Sauroposeidon holotype: 125cm
  • KLR1508-77-2, Ruyangosaurus giganteus referred specimen: 124cm
  • MPEF-PV 3400/3, Patagotitan holotype: 120cm (+?)
  • MPM 10002, Puertasaurus holotype: 118cm

You may be surprised to see the Price River 2 cervical in there. It was reported in an SVP abstract a few years ago (I’ll dig up that ref and update this post), and Mike and I saw it last year on the Sauropocalypse. We measured the centrum at 129cm, making it just a bit longer than the longest centrum of Sauroposeidon, and therefore the second-longest vertebra of anything ever.

Aside – I’m probably getting a reputation as a big ole meanie when it comes to debunking “world’s largest dinosaur” claims. If I’m willing to take the lead in kicking my own dinosaur down the ladder, don’t expect me to be kind to yours. I follow where the numbers lead.

Now, here’s an interesting thing – now that Sauroposeidon is coming out as a basal titanosaur, rather than a brachiosaur, it might not have been a skinny freak. The 120cm cervical of Patagotitan makes the 125cm cervical of Sauroposeidon and the 129cm cervical from Price River 2 look even more tantalizing. Maybe it’s super-giant sauropods all the way down.

The best-preserved presacral vertebra of Vouivria damparisensis (Mannion et al. 2017: fig. 10).

New goodies out today in PeerJ: Tschopp and Mateus (2017) on the new diplodocid Galeamopus pabsti, and Mannion et al. (2017) redescribe and name the French ‘Bothriospondylus’ as Vouivria damparisensis.

C7 of Galeamopus pabsti (Tschopp and Mateus 2017: fig. 24).

Both papers are packed with interesting stuff that I simply don’t have time to discuss right now. Possibly Mike and I will come back with subsequent posts that discuss these critters in more detail. We both have a connection here besides our normal obsession with well-illustrated sauropods – Mike reviewed the Galeamopus paper, and I reviewed Vouivria. Happily, both sets of authors chose to publish the peer-review histories, so if you’re curious, you can go see what we said.

For now, I’ll just note that C7 of Galeamopus pabsti, shown above, is intriguingly similar in form to Vertebra ‘R’ of YPM 429, the ‘starship’ Barosaurus cervical (illustrated here). Mike and I spent a lot of time puzzling over the morphology of that vert before we convinced ourselves that much of its weirdness was due to taphonomic distortion and a restoration and paint job that obscured the fact that the metapophyses were missing. Given our ongoing project to unravel the wacky morphology of Barosaurus, I’m looking forward to digging into the morphology of G. pabsti in more detail.

I’ll surely irritate Mike by saying this, but my favorite figure in either paper is this one, Figure 4 from Tschopp and Mateus (2017). I can’t remember ever seeing an exploded skull diagram like this for a sauropod before, but it’s extremely helpful and I love it.

And that’s all for now. Go read these papers – they’re both substantial contributions with intriguing implications for the evolution of their respective clades. Congratulations to both sets of authors for producing such good work.

References

  • Mannion PD, Allain R, Moine O. (2017) The earliest known titanosauriform sauropod dinosaur and the evolution of Brachiosauridae. PeerJ 5:e3217 https://doi.org/10.7717/peerj.3217
  • Tschopp E, Mateus O. (2017) Osteology of Galeamopus pabsti sp. nov. (Sauropoda: Diplodocidae), with implications for neurocentral closure timing, and the cervico-dorsal transition in diplodocids. PeerJ 5:e3179 https://doi.org/10.7717/peerj.3179
jvp-fig-12

Fig. 14. Vertebrae of Pleurocoelus and other juvenile sauropods. in right lateral view. A-C. Cervical vertebrae. A. Pleurocoelus nanus (USNM 5678, redrawn fromLull1911b: pl. 15). B. Apatosaurus sp. (OMNH 1251, redrawn from Carpenter &McIntosh 1994: fig. 17.1). C. Camarasaurus sp. (CM 578, redrawn from Carpenter & McIntosh 1994: fig. 17.1). D-G. Dorsal vertebrae. D. Pleurocoelus nanus (USNM 4968, re- drawn from Lull 1911b: pl. 15). E. Eucamerotus foxi (BMNH R2524, redrawn from Blows 1995: fig. 2). F. Dorsal vertebra referred to Pleurocoelus sp. (UMNH VP900, redrawn from DeCourten 1991: fig. 6). G. Apatosaurus sp. (OMNH 1217, redrawn from Carpenter & McIntosh 1994: fig. 17.2). H-I. Sacral vertebrae. H. Pleurocoelus nanus (USNM 4946, redrawn from Lull 1911b: pl. 15). I. Camarasaurus sp. (CM 578, redrawn from Carpenter & McIntosh 1994: fig. 17.2). In general, vertebrae of juvenile sauropods are characterized by large pneumatic fossae, so this feature is not autapomorphic for Pleurocoelus and is not diagnostic at the genus, or even family, level. Scale bars are 10 cm. (Wedel et al. 2000b: fig. 14)

The question of whether sauropod cervicals got longer through ontogeny came up in the comment thread on Mike’s “How horrifying was the neck of Barosaurus?” post, and rather than bury this as a comment, I’m promoting it to a post of its own.

The short answer is, yeah, in most sauropods, and maybe all, the cervical vertebrae did lengthen over ontogeny. This is obvious from looking at the vertebrae of very young (dog-sized) sauropods and comparing them to those of adults. If you want it quantified for two well-known taxa, fortunately that work was published 16 years ago – I ran the numbers for Apatosaurus and Camarasaurus to see if it was plausible for Sauroposeidon to be synonymous with Pleurocoelus, which was a real concern back in the late ’90s (the answer is a resounding ‘no’). From Wedel et al. (2000b: pp. 368-369):

Despite the inadequacies of the type material of Pleurocoelus, and the uncertainties involved with referred material, the genus can be distinguished from Brachiosaurus and Sauroposeidon, even considering ontogenetic variation. The cervical vertebrae of Pleurocoelus are uniformly short, with a maximum EI of only 2.4 in all of the Arundel material (Table 4). For a juvenile cervical of these proportions to develop into an elongate cervical comparable to those of Sauroposeidon, the length of the centrum would have to increase by more than 100% relative to its diameter. Comparisons to taxa whose ontogenetic development can be estimated suggest much more modest increases in length.

Carpenter & McIntosh (1994) described cervical vertebrae from juvenile individuals of Apatosaurus and Camarasaurus. Measurements and proportions of cervical vertebrae from adults and juveniles of each genus are given in Table 4. The vertebrae from juvenile specimens of Apatosaurus have an average EI 2.0. Vertebrae from adult specimens of Apatosaurus excelsus and A. louisae show an average EI of 2.7, with an upper limit of 3.3. If the juvenile vertebrae are typical for Apatosaurus, they suggest that Apatosaurus vertebrae lengthened by 35 to 65% relative to centrum diameter in the course of development.

The vertebrae from juvenile specimens of Camarasaurus have an average EI of 1.8 and a maximum of 2.3. The relatively long-necked Camarasaurus lewisi is represented by a single skeleton, whereas the shorter-necked C. grandis, C. lentus, and C. supremus are each represented by several specimens (McIntosh, Miller, et al. 1996), and it is likely that the juvenile individuals of Camarasaurus belong to one of the latter species. In AMNH 5761, referred to C. supremus, the average EI of the cervical vertebrae is 2.4, with a maximum of 3.5. These ratios represent an increase in length relative to diameter of 30 to 50% over the juvenile Camarasaurus.

If the ontogenetic changes in EI observed in Apatosaurus and Camarasaurus are typical for sauropods, then it is very unlikely that Pleurocoelus could have achieved the distinctive vertebral proportions of either Brachiosaurus or Sauroposeidon.

apatosaurus-cm-555-c6-centrum-and-arch-united

C6 of Apatosaurus CM 555 – despite having an unfused neural arch and cervical ribs, the centrum proportions are about the same as in an adult.

A few things about this:

  1. From what I’ve seen, the elongation of the individual vertebrae over ontogeny seems to be complete by the time sauropods are 1/2 to 2/3 of adult size. I get this from looking at mid-sized subadults like CM 555 and the hordes of similar individuals at BYU, the Museum of Western Colorado, and other places. So to get to the question posed in the comment thread on Mike’s giant Baro post – from what I’ve seen (anecdata), a giant, Supersaurus-class Barosaurus would not necessarily have a proportionally longer neck than AMNH 6341. It might have a proportionally longer neck, I just haven’t seen anything yet that strongly suggests that. More work needed.
  2. Juvenile sauropod cervicals are not only shorter than those of adults, they also have less complex pneumatic morphology. That was the point of the figure at the top of the post. But that very simple generalization is about all we know so far – this is an area that could use a LOT more work.
  3. I’ve complained before about papers mostly being remember for one thing, even if they say many things. This is the canonical example – no-one ever seems to remember the vertebrae-elongating-over-ontogeny stuff from Wedel et al. (2000b). Maybe that’s an argument for breaking up long, kitchen-sink papers into two or more separate publications?

Reference

Wedel, M.J., Cifelli, R.L., and Sanders, R.K. 2000b. Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon. Acta Palaeontologica Polonica 45:343-388.

Long-time SV-POW! readers will remember that three years ago, full of enthusiasm after speaking about Barosaurus at the Edinburgh SVPCA, Matt and I got that talk written up in double-quick time and had it published as a PeerJ Preprint in less than three weeks. Very quickly, the preprint attracted substantive, helpful reviews: three within the first 24 hours, and several more in the next few days.

This was great: it gave us the opportunity to handle those review comments and get the manuscript turned around into an already-reviewed formal journal submission in less then a month from the original talk.

So of course what we did instead was: nothing. For three years.

I can’t excuse that. I can’t even explain it. It’s not as though we’ve spent those three years churning out a torrent of other awesome papers. We’ve both just been … a bit lame.

Anyway, here’s a story that will be hauntingly familiar. A month ago, full of enthusiasm after speaking about Barosaurus at the Liverpool SVPCA, Matt and I found ourselves keen to write up that talk in double-quick time. It’s an exciting tale of new specimens, reinterpretation of an important old specimen, and a neck eight times as long as that 0f a world-record giraffe.

But it would be crazy to write the new Barosaurus paper without first having dealt with the old Barosaurus paper. So now, finally, three years on, we’ve done that. Version 2 of the preprint is now available (Taylor and Wedel 2016), incorporating all the fine suggestions of the people who reviewed the first version — and with a slightly spiffed-up title. What’s more, the new version has also been submitted for formal peer-review. (In retrospect, I can’t think why we didn’t do that when we put the first preprint up.)

Taylor and Wedel 2016: Figure 3. Barosaurus lentus holotype YPM 429, vertebra R, C?15. Top row: dorsal view; middle row, left to right: posterior, right lateral and anterior views; bottom row: ventral view, from Lull (1919: plate II). Note the apparently very low, undivided neural spine at the intersection of the PRSLs and POSLs, forward-shifted neural arch, broad prezygapophyses, broad, wing-like prezygadiapophyseal laminae, and great width across the diapophyses and across the parapophyses. Abbreviations: dia, diapophysis; para, parapophysis; prz, prezygapophysis; prdl, prezygadiapophyseal lamina; spol, spinopostzygapophyseal lamina; sprl, spinoprezygapophyseal lamina. Scale bar = 500 mm.

Taylor and Wedel 2016: Figure 3. Barosaurus lentus holotype YPM 429, vertebra R, C?15. Top row: dorsal view; middle row: posterior, right lateral and anterior views; bottom row: ventral view, from Lull (1919: plate II). Note the apparently very low, undivided neural spine at the intersection of the SPRLs and SPOLs, forward-shifted neural arch, broad prezygapophyses, broad, wing-like prezygadiapophyseal laminae, and great width across the diapophyses and across the parapophyses. Abbreviations: dia, diapophysis; para, parapophysis; prz, prezygapophysis; prdl, prezygadiapophyseal lamina; spol, spinopostzygapophyseal lamina; sprl, spinoprezygapophyseal lamina. Scale bar = 500 mm.

A big part of the purpose of this post is to thank Emanuel Tschopp, Mark Robinson, Andy Farke, John Foster and Mickey Mortimer for their reviews back in 2013. I know it’s overdue, but they are at least all acknowledged in the new version of the manuscript.

Now we cross our fingers, and hope that the formally solicited reviews for the new version of the manuscript are as helpful and constructive as the reviews in that first round. Once those reviews are in, we should be able to move quickly and painlessly to a formally published version of this paper. (I know, I know — I shouldn’t offer such a hostage to fortune.)

Meanwhile, I will finally be working on handling the reviews of this other PeerJ submission, which I received back in October last year. Yes, I have been lax; but I am back in the saddle now.

References

  • Taylor, Michael P., and Mathew J. Wedel. 2016. The neck of Barosaurus: longer, wider and weirder than those of Diplodocus and other diplodocines. PeerJ PrePrints 1:e67v2 doi:10.7287/peerj.preprints.67v2

UPDATE 19 May 2016

I belatedly realized that I caused some confusion in the original version of this post. This will hopefully sort things out:

NAMAL Barosaurus cervical with features labeled

The ventrolateral processes (1) are nothing new. As Ken Carpenter pointed out in a comment, Hatcher noted them back in 1901 in his monograph on Diplodocus carnegii. These are the features I describe below as being, “huge in Barosaurus, big in Diplodocus, small in Apatosaurus, and nonexistent in Haplocanthosaurus, Camarasaurus, and the brachiosaurids, at least from what I’ve seen.” To clarify: occasionally in camarasaurs and frequently in brachiosaurs you can trace a ridge along the ventrolateral margin of the centrum from the parapophysis to the cotyle. But these ridges are basically just the ‘corners’ of the centrum, leftover by the lateral and ventral waisting of the centrum – they do not project beyond the margin of the cotyle. In contrast, what I’ve been calling the ventrolateral flanges in diplodocids do project beyond the margins of the cotyle – they are additive structures, not just architectural leftovers. They also don’t vary much, other than to be more pronounced in more posterior cervicals.

The irregular ventral ridges (2) are a totally different thing. They’re on or near the sagittal midline of the centrum, usually restricted to the anteroposterior middle of the ventral centrum (so, about halfway between the condyle and the cotyle), and as my preferred term implies, highly variable among individuals and even among vertebrae in a series.

Hope that helps! (Original post starts below.)

– – – – – – – – – – – – – – – – – – – – –

2005-07-29 BYU 16918 Diplodocus left lateral

Back in 2005 I visited BYU while I was working on my dissertation. Back then I noted ventral ridges in a few diplodocine cervical vertebrae. (I hesitate to call such flimsy things ‘keels’.)

Up above is BYU 16918, a mid-to-posterior cervical vertebra of Diplodocus from the famous Dry Mesa Quarry. Here it is again in posterior view:

2005-07-29 BYU 16918 Diplodocus posterior view labeled

The things I have labeled VLF here are ventrolateral flanges, which are huge in Barosaurus, big in Diplodocus, small in Apatosaurus, and nonexistent in Haplocanthosaurus, Camarasaurus, and the brachiosaurids, at least from what I’ve seen. See this post for details. I know that the left VLF here looks like a second ridge, but the cotyle is broken off in such a way that we’re seeing the fossa just dorsal to the VLF margin. The ridge itself is skewed to the right, which could be natural or a result of taphonomy – as you can see from the photo at the top of the post, this vert has seen better days.

Here’s another Dry Mesa vert, BYU 11617, this time an anterior cervical of Barosaurus and in left lateral view:

2005-07-29 BYU 11617 Barosaurus left lateral

Again in right lateral view – on this side you can see the fossa in the VLF more clearly:

2005-07-29 BYU 11617 Barosaurus right lateral

And here’s the ventral view showing the ridge:

2005-07-29 BYU 11617 Barosaurus ventral view labeled

I noted these things in my notebook back when, filed them under, “Huh. How about that?” and went on with life.

Then last week Mike and I were at the North American Museum of Ancient Life in Lehi, Utah, and we saw this super-nice Barosaurus cervical on display in the prep lab (left ventro-lateral view). Check out the monster ventrolateral flanges, and the ridges between them at about mid-centrum.

IMG_4605

Here’s another view, a more square-on ventral this time:

IMG_4604

We owe a big thank you to Rick Hunter, who let us into the prep lab at the North American Museum of Ancient Life to see the Barosaurus material up close.

So what’s the deal with these ridges? I assume that they’re caused by pneumatic diverticula remodeling the ventral surface of the centrum. We know that such diverticula were down there because there are actual foramina on the ventral centrum in Supersaurus, many apatosaurines (Lovelace et al., 2008), many brachiosaurids, and probably loads of other things that haven’t been checked. Oddly enough, I’ve never seen the ridges in any of those other taxa. It seems that you get foramina or ridges, but not both. I have no idea what’s up with that – to paraphrase Neal Stephenson, Barosaurus cervicals are confections of air and marketing, and you’d think that if any sauropod would have straight-up foramina down there, it would be Barosaurus. But Barosaurus gets ridges and clunky old Apatosaurus gets foramina (sometimes, not all the time).

It’s a sick world, I tell you.

Reference

  • Lovelace, D. M., Hartman, S. A., & Wahl, W. R. (2007). Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny. Arquivos do Museu Nacional, Rio de Janeiro 65(4):527-544.

Things remain frantic on the Sauropocalypse tour. Today, we were back at the BYU Museum of Paleontology, working on four or five separate projects. Here’s Matt, photographing broken bone of the iconic Supersaurus cervical BYU 9024, while a pallet of Big Pink Apatosaur cervicals wait for attention in the background:

2016-05-11 15.42.40

You’ve seen this bone before – I first posted on it 8 years ago this month, and it turned up again here and here. It is still the longest known vertebra of any animal that has ever lived.

And here’s Mike, getting Jensen’s sculpture of the same vertebra down from storage to compare it to the original:

IMG_9232

In Jensen’s (1985) original description of this vertebra – which he at first referred to Ultrasauros – the only relevant illustration he included was one of the model, so it was good to see this bit of history in the flesh (Jensen did include photos of the actual bone in later papers). We’ll show the two vertebrae, real and sculpted, side by side in a future post.

References

  • Jensen, J. A. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. Great Basin Naturalist 45, 697-709.

DSCN1044b

Not much to say this time – the pictures tell the story for now.

DSCN1033b

It was a pretty transcendental experience, as I imagine it must be for anyone who loves dinosaurs, or has a pulse.

DSCN1059b

A huge thank-you to Dan Chure, the Park Paleontologist for the Monument, who conveyed us safely up and down the Wall, taught us about the prehistory of the site and the human history of its excavation and conservation, held scale bars, moved backpacks, took photos, and generally seemed to be having just as much fun as we were. This has been a common theme on the trip – every single person we’ve interacted with at a museum or fossil site has been unfailingly welcoming and generous with their time and knowledge. Whatever challenges vert paleo faces, a lack of wonderful people is not one of them.

DSCN1112b

I was up there, too, for the second time in my life – that will be a post for another day. For now, just bask in the glory of Mike basking in the glory of a literally mind-numbing array of amazing fossils.