New hotness out today: Miragaia, a new long-necked stegosaur from the Late Jurassic of Portugal (Mateus et al. 2009). What is “long-necked” for a stegosaur? In this case, well over a meter! That may not sound too impressive for those of you who have gotten complacent about 10-meter-plus sauropod necks, but it’s a big deal. Miragaia is described as a sauropod mimic, and with good reason: its body proportions are not that different than those of a basal sauropod.

The number of ways to increase the proportional length of the neck are limited: you can add cervicals, or recruit dorsals into the neck, or make the individual vertebrae longer, or do some combination of  the above. In sauropods, different clades took different routes. Brachiosaurids kept a fairly primitive cervical count of  13 but made the individual vertebrae crazy long. Diplodocids recruited dorsals into the neck, and some (like Barosaurus and Supersaurus) also made the vertebrae crazy long. Mamenchisaurids and Euhelopus added cervicals (independently), up to a total of 17 or more, and some (like Omeisaurus)–are you ready for it?–also made the vertebrae crazy long.

In general, stegosaurs took an evolutionary walk through Door Number 2: turning dorsals into cervicals. Mateus et al. (2009) show this nicely in a table; the number of presacrals (cervicals plus dorsals) in stegosaurs stays about the same, between 25 and 27, but between the basal Huayangosaurus and the derived Stegosaurus 3 or 4 dorsals go forward to play for the other team. Is dorsal recruitment sufficient to explain the long neck of Miragaia? Hard to say, since the dorsal series has not been found. But Miragaia‘s count of 17 cervicals is significantly more than Stegosaurus‘s 13. If Miragaia didn’t add any cervicals but only recruited dorsals, it would have had only 9 of the latter. That’s not impossible–Barosaurus did that very thing–but it’s weird, and extreme. As Mateus et al. (2009:p. 4) state, “Miragaia possessed more cervical vertebrae than any other non-avian archosaur, except the Chinese sauropods Mamenchisaurus, Omeisaurus and Euhelopus, also with 17″. And yet the individual vertebrae are pretty short, no longer than in your not-exactly-average Stegosaurus.

brachytrachelopan-vs-miragaia-480

I couldn’t resist pitting Miragaia, the longest-necked stegosaur (so far!) against Brachytrachelopan, the shortest-necked sauropod (so far!). Miragaia is stolen from Mateus et al. (2009:fig. 1a), and Brachytrachelopan from Rauhut et al. (2005:fig. 1a). Both critters come with the 1 meter scale bars from their respective figures. I’m in there for scale, too, at 6’2″ or 1.88 meters. Sauroposeidon looms in the background, just to keep things in perspective. The entire neck of Miragaia might have been about as long as one of the middle cervicals of Sauroposeidon or Supersaurus.

Still, you know.

Not bad.

(for a stinkin’ ornithischian)

A couple more pictures here.

References

We warned you that the Awesome was coming … now it’s here.  The first installment of Awesome, anyway, and there’s plenty more to come.

mike-by-jango-elbow-480px

Matt and I have just returned from a nine-day trip to Germany that was pretty much Heaven-on-Earth for us.  The first three days were spent in Bonn, at the first open workshop of the DFG-funded Biology of the sauropod dinosaurs: the
evolution of gigantism
project.  Happily, Matt and I were each able to give two talks: his on the sauropod lung and the repeated evolution of very long necks, mine on limb-bone cartilage strength and habitual neck posture.  (There is a lot more to say about this workshop, which was fascinating for all sorts of reasons, but I am going to press quickly onwards because you want to get to the pictures.)

After the workshop proper came a three-day field-trip, which took us first to the Dinopark at Münchehagen, where we saw the quite startling Europasaurus material, then to the Langenberg Quarry where Europasaurus is found, and finally to Berlin, home of the Humboldt Museum für Naturkunde and therefore also of Brachiosaurus brancai (at least, since it was dug up in Tanzania and sent there).  Matt and I, and Mike D’Emic, stayed on for two further days after the field-trip’s visit to the Humboldt, to work on the Tendaguru sauropod material.

Soon we’ll show you some of the great stuff in the collections, but for now I want to concentrate on the public gallery.  It’s three years since, at SVPCA 2005, I described this gallery’s brachiosaur mount as “the single finest object in the known universe”, and that was true even then.  But now the glorious material has been remounted by RCI, under the supervision of Kristian Remes, in a more anatomically correct and far more dynamic pose, and it’s better still.  (The photo at the top shows the remounted brachiosaur, with me for scale next to its elbow.  I bet you didn’t even notice me there when you first looked at it.)  Not only that, but Dicraeosaurus has also been remounted, along with the museum’s cast of the Carnegie Diplodocus (standing in for the Tendaguru diplodocines Tornieria and Australodocus), so that the three sauropods together make a stunning display of Tendaguru sauropod diversity.  (There’s a picture of the whole exhibit at the end of this post).  This is so awesome that I have had to revise my previous opinion that the public gallery of the OUMNH is my favourite in the whole world.  It is now an honourable second.

The Humboldt staff were very good to us, and allowed us quite a bit of quality time alone with the mounts, in the mornings before the public arrived and in the evenings after they’d gone.  Not only that, but they equipped us with a stepladder and a pair of arsegravies to stand it on, so it wouldn’t damage the exhibit’s floor covering — so we were able to get close to the material.  Here, for example, is Matt, carefully checking the proximal caudals for [REDACTED], with Dicraeosaurus‘s head and neck in the background:

matt-with-jango-tail-480pxh

Better still, I was able to get right up inside the brachiosaur’s torso, which I needed to do in order to measure its girth:

mike-inside-jango-480px

(There was no possible way to run a tape measure across the rib-cage without a second ladder, so I had to drop lines to the ground: Matt marked where they fell, then measured the distance between the marks.  Brachiosaurus brancai is A LOT bigger than Diplodocus.)

When palaeontologists gather around a mounted skeleton, it’s traditional to pick holes in the mount: in extreme cases, you can find silly mistakes like the scapulae being mounted upside down (juvenile Mamenchisaurus casts at the FMNH), but there is always something to criticise.  Well, almost always, it turns out.  Matt and I stared at that brachiosaur mount pretty intensely for three days, and we came up with, basically, nothing.  Kristian and RCI did a great job on it: it’s completely convincing not only as a piece of skeletal anatomy but also as an animal.  It looks alive.  (After a while I did manage to come up with one criticism: the most posterior cervical ribs are too long and thin.  But that’s all I’ve got.)

Finally, here is that whole-exhibit photograph that I promised you.  In case you need to be told, the brachiosaur is the big one, Diplodocus is to the right, and poor little Dicraeosaurus is half-hidden off to the left, behind the big fella.

humboldt-exhibit-480px

(Sorry about the glass refections in this photo: it was taken from a room that has been fitted with unopenable windows, so I think this is unavoidable.  Also sorry that the head is out of focus.  To fit the whole exhibit in, I had to use a wide-angle lens, and it distorts the edges of the picture.)

In future Shedloads of Awesome posts, we’ll show you Dicraeosaurus in more detail, some of the Awesome down in the collections (including the brachiosaur skull, if we can find a way to fit something so off-topic into SV-POW!), and maybe, if you’re luckly, some of that Europasaurus material.

What with all the fuss over Aerostron, it seems that we missed SV-POW!’s first birthday. Yes, it’s been just over a year since the very first post, Hello world!, showed us the Brachiosaurus brancai cervical vertebra HMN SII:C8 that we have seen so many times since in various ways. Since we kicked off on 1st October 2007, we’ve written a total of 82 posts (so more like one and a half per week than the one a week we advertised), and accumulated 1002 comments. (Congratulations to Andy Farke, who wrote the 1000th comment).

We’ve covered a lot of ground this year, from the the frivolous to the ferociously technical, so it’s hard to pick favourites. But from my own very biased perspective, I particularly enjoyed all eight days of the extended Xenoposeidon week, a rather exhausting series of posts that may make Xeno the most blogged dinosaur on the Internet — or at least, the most blogged mid-to-posterior partial dorsal vertebra. Also noteworthy was Matt’s flagrant playing-to-the-gallery “showdown” and Darren’s observation of a newly recognised site of pneumaticity (which I want to cite in a paper but won’t be allowed to). [Note added 22 June 2014: I did indeed cite it in a paper.]

Still, there’s no hesitation for me in picking my favourite series: it would have to be the four posts of axial-anatomy humiliation, Your neck is pathetic, Your torso is also pretty lame, Your sacrum is negligible and Your coccyx is contemptible.

A highlight this year was hearing SV-POW! namechecked by John Hutchinson in his introductory remarks at a workshop on functional morphology at the Natural History Museum. I also heard a rumour somewhere that Paul Upchurch tells his students to read this site. I have no idea whether that’s true or not, but I think it sounds pretty awesome so I am going to assume that it is until I hear otherwise.

I seem to recall when we kicked this thing off that we intended only to run it for one year, then archive it and shut it down. But it’s been going well enough, and we’ve enjoyed it enough, that there is no prospect of our calling it a day for a while yet. One of the reasons for that, I think, is that sharing a blog between three people has worked fantastically well. It’s meant that we’ve been able to keep up a half-decent rate of posting non-trivial articles without the load on any one of us being too great. (How on earth Darren manages to post daily on Tetrapod Zoology I can’t imagine). And this is my message to the world on the occasion of SV-POW!’s birthday: shared blogging is excellent, and I would love to see more team-run palaeo blogs out there. I’ve joked in the past about blogs like Basal Ornithopod Third Metatarsal Picture of the Week, but in all seriousness I would love to see people taking on super-specialised aspects of dinosaur palaeo as we’ve done here. I would read such blogs avidly, and our modest-but-non-negligible hit-counts here at SV-POW! (69,170 hits as I write this) suggests that there is a hardcore market for this kind of blog. So have at it, people!

As it happens, right around now is also an important time for me, Matt and Darren because on Friday night we submitted our first joint-authored paper. I’ll say no more about that now, because hopefully before too long we’ll be able to discuss the published version. [Note added 22 June 2014we did, extensively.] But making that submission was a landmark moment for The Three SV-POW!sketeers. Hopefully there’ll be more where that came from. [Note added 22 June 2014: there was.]

Finally, I give you the actual sauropod vertebra you’ve all been waiting for. It is a cast of the 2nd dorsal vertebra (the only one preserved ) of the holotype and only specimen of Puertasaurus reuili Novas et al. 2005, with lead author Fernando E. Novas himself for scale. This is one of those photos that just make you go “Woah!”; or, if you are so inclined, “Dude!”. Enjoy!

Puertasaurus reuili, second dorsal vertebra, anterior view.

Puertasaurus reuili, second dorsal vertebra, in anterior view, with Fernando E. Novas for scale.

Reference

The remarkable object shown here (the one on the left) is a copy of the famous BYU 9044 bone. I know you’ve all heard the story a million times before: it’s the stuff of late-night parties, and fireside stories-from-grandpa, but it would be wrong not to recount it again. First described by Jensen (1985) as the holotype of the new brachiosaurid Ultrasaurus macintoshi (a name that was later changed to Ultrasauros macintoshi), it was much later shown – by Curtice et al. (1996) – to belong not to a brachiosaur, but to a diplodocid. Furthermore, because it was found literally among the bones of the holotype of the diplodocid Supersaurus vivianae, the most logical course of action was to, alas, sink Ultrasauros into Supersaurus… and hence Ultrasauros was no more.

Jensen (1985) figured the vertebra in right lateral view, so the left-hand view you’re getting here is the sort of thing that has sauropod vertebra fans swooning and lying awake at night. There is, of course, a ton of neat anatomy to talk about here.. but I don’t have time to talk about it. You will no doubt have been impressed by the size: the scale is kindly provided by Sam Heads of Palaeoentemology and Insect Evolution.

References

  • Curtice, B., Stadtman, K. L. & Curtice, L. J. 1996. A reassessment of Ultrasauros macintoshi (Jensen, 1985). In Morales, M. (ed) The Continental Jurassic. Museum of Northern Arizona Bulletin 60, 87-95.
  • Jensen, J. A. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. Great Basin Naturalist 45, 697-709.

Special Bonus: Non-Sauropod Saurischian Vertebra Picture Of The Week!

Hi, Mike here. It’s a bit rude to tag onto the end of Darren’s post, but I don’t want to make a brand new post and shove Ultrasaurus, er, Ultrasauros off the front-page. Anyway, I’ve made available my close-up photos of a turkey cervical. Click through the image for details. Enjoy!

Turkey cervical C7 multiview on white background

This one, obviously, is a follow-up to this one. Mark drew the picture, Mike had the idea, Mark gave the go-ahead, and here we are. Cry havoc and let slip the azhdarchids of war!

Who’s next? Who wants some? You want a little? Huh? Huh?

First, some horn-tooting. A few years ago I realized that I good lateral-view photos of lots of big stuff–a blue whale skeleton, a Brachiosaurus skeleton, a big bull elephant, myself–and I put together a composite picture that showed everything together and correctly scaled. Various iterations of the project, which I undertook solely for my own amusement, are here, here, and here. Here’s the final product:

From left to right by skull position those are:

  • the mounted skeleton of Balaenoptera musculus at the Long Marine Lab in Santa Cruz, California;
  • the mounted six-ton (not ten-ton; see the comments from June 3 and 4, below) bull Loxodonta africana from the Field Museum in Chicago, Illinois;
  • the mounted skeleton of Brachiosaurus altithorax from the same museum;
  • yours truly;
  • and Mike Taylor.

Everything is scaled correctly, and none of the critters in the picture represent the maximum size attained by their species (although I come pretty close). The whale is, at 87 feet, about 80% of the size of the largest known individuals. The Brachiosaurus skeleton is about 85% of the size of the largest known specimens in the genus, and the elephant is 77% of the size of the world record (these are all in linear terms).

I often blog like I’m in a vacuum but somehow people do find out about this stuff, and the good folks at the University of British Columbia’s Beaty Biodiversity Museum asked if they could use the photo on their blue whale page. Naturally I agreed.

Then last week I was contacted by them again. The museum’s blue whale project was to be featured on the evening news and they wanted to use the photo in the story. I’m never one to turn down free publicity in the interests of science. Here’s the clip (after a brief ad).

Since it comes up frequently (for me, at least), and since we’re talking about blue whales anyway, I’ll tackle the age-old question about which is bigger, a blue whale or the largest dinosaur.

In this corner, the defending champion: Balaenoptera musculus

Everyone “knows” that blue whales are 100 feet long and weigh 100 tons, right?

Wrong. According to Wood (1982, p. 7), “The largest accurately measured blue whale on record (length taken in a straight line parallel to the body axis from the tip of the upper jaw to the notch in the tail flukes) was a female…which measured 107 Norwegian fot (= 110 ft 2 1/2 in 33.59m).” Wood also lists numerous other confirmed records of blue whales over 100 feet long. Apparently they were not that uncommon in the Antarctic before the intensive whaling of the early 20th century.

The common perception of the 100ft/100 ton whale is even farther off when it comes to maximum weight. Weighing big whales is a pain in the ass. The biggest whale that has ever been weighed intact was a 59 ft (18m) sperm whale that was picked up by three floating cranes and weighed at 58 tons (53 metric tons; all of these data are from Wood 1982). Much larger sperm whales are known; the largest possibly being 84 ft (25.6m) long and weighing perhaps 88 tons (80 metric tons). All whales larger than that 58-ton sperm whale have had to be weighed piecemeal, by chopping them up and weighing the bits. Inevitably lots of blood and fluid are lost this way, so the piecemeal weight is usually about 6% less than the true body weight.

Nevertheless, there are lots of records of big blues weighing more than 150 tons, and the heaviest one on record is a pregnant female that weighed a jaw-dropping 209 tons (190 metric tons), more than twice the commonly quoted maximum size for this animal. Surely, surely, one thinks, that is the ne plus ultra of vertebrate mass.

Not so. Wood (1982, p. 9) describes a ‘very fat’ female, 91 ft (27.7m) long, which “yielded a record 305 barrels of oil weighing 51.85 tonnes [57 English or short tons]. Unfortunately this enormous whale was not weighed piecemeal, but on the basis of its oil yield it must have scaled at least 200 tonnes [220 short tons; emphasis in the original]!

And in this corner, the contenders: sauropods!

The longest sauropod known from decent remains is Supersaurus, for which Lovelace et al. (2007) estimate a total length of 33-34 meters (108-111 ft) for Jimbo, the new specimen from Wyoming. The Dry Mesa specimen is apparently slightly larger. Seismosaurus has now been sunk into Diplodocus, and was apparently no more than 30m (98 ft) long, enthusiastic estimates to the contrary notwithstanding (see Lovelace et al. 2007 for details, and also check out Scott Hartman’s site for lots of good info and cool skeletal reconstructions). Because it was so slender, Supersaurus weighed less than you might think; Lovelace et al. estimate Jimbo’s mass at 35-40 tons.

The most massive sauropod for which a reasonably secure mass estimate is possible is Argentinosaurus, which Mazzetta et al. (2004) estimated to have weighed 80.5 tons (73 metric tons). Old estimates of up to 80 tons for Brachiosaurus are based on models that can most charitably be described as just horribly, stupidly fat; all of the recent sane estimates put the better-known big specimens of Brachiosaurus between about 30 and 45 tons, with the very largest known specimens possibly getting up to 50 or 60 tons. Irritatingly, during the 1980s a bunch of mass estimates for “Ultrasauros” came out that were based on the ridiculous 80-ton estimate for Brachiosaurus, and put the mass of “Ultrasauros” at 180 tons. As we shall see, there is no good evidence that any sauropod ever got within 40 tons of that mark.

Then there are the semi-apocryphal gigapods, Bruhathkayosaurus and Amphicoelias fragillimus. Bruhathkayosaurus is reported to have a 2-meter-long tibia, which would make it perhaps 20% larger than Argentinosaurus in linear terms, and 70% more massive (mass scales with the cube of the linear dimension, and 1.2 x 1.2 x 1.2 = 1.728). Assuming that the proposed tib is really a tib and not an eroded femur or something, and that Bruhathkayosaurus was built like the very robust Argentinosaurus and not like, say, the very slender Brachiosaurus, and that the mass estimate for Argentinosaurus is accurate, Bruhathkayosaurus may have weighed as much as 139 tons (126 metric tons).

Amphicoelias fragillimus appears to have been built like a big Diplodocus–well, okay, an extremely mind-blowingly immense Diplodocus–and assuming the sole surviving drawing is legit and correctly scaled, it was just completely nuts (way more so than Apatosaurus; see Darren’s thoughts here and here). The femur may have been anywhere from 3-4.6 meters long (Carpenter 2006), and was more likely in the upper part of that range. In the big mounted skeletons of Diplodocus, the femora are just a little over 1.5 meters long. So Amphicoelias may have been 2-3 times the size of Diplodocus in linear terms. Carpenter (2006) posited a length of 190ft (58m) and a weight of 135 tons (122.4 metric tons).

Interlude: world record animals

The biggest known whales really are probably close to being the biggest representatives of their species. The individuals listed above are the largest known from a sample of more than 300,000 blue whales killed in the early 20th century. That’s a big pool. Supersaurus and Argentinosaurus are both known from two specimens, and Bruhathkayosaurus and A. fragillimus from one specimen each. The chances that these largest-known sauropods are really the largest sauropods that ever lived is vanishingly small.

And the winner is…

For mass, no question, the blue whale. Even our most liberal estimates of the most poorly known gigapods don’t come close to the 200-ton mark, which blue whales are known to exceed.

For length, probably a sauropod. A huge sample of blue whales included none longer than 110 feet, while our comparatively pathetic sample of sauropods has already turned in one animal (Supersaurus) that may have just edged that out, and another (A. fragillimus) that–assuming it was really as big as we think–blows it out of the water (so to speak).

References

Long-time SV-POW! readers will have detected a brachiosaurid bias in our writings, and this is for a good reason: it is because brachiosaurids are best. They just are. But there are a few diplodocids that really get our juices flowing — not just Amphicoelias fragillimus (which we would post on, except that Darren did such a good job on it a while back on Tet Zoo [part 1, part 2]) but also the enigmatic Supersaurus. Until very very recently, this genus was known just from a single specimen, recovered by “Dino” Jim Jensen, and formally described by him in 1985, twelve long years after the name first appeared in print, in that well-known international journal Reader’s Digest. (No, I am not kidding.)

I don’t want to say too much about Jensen’s specimen right now, because I plan to cover it in more detail soon, but I do need to say that Jensen suffered from two debilitating conditions. The first was a congenital inability to see a scapulocoracoid without lying down in the dirt next to it for a photographer. Exhibit A is Jensen (1985:fig 4A), which also appears as Jensen (1987:fig 6A):

And Exhibit B is figure 6B from the very same paper:

fig 6b -- Jensen lying next to another big scapulocoracoid

(“What is this?”, I hear you cry. “Sauropod Scapulocoracoid Picture of The Week?” Sorry for the appendicularity, we’ll be getting you back to your regularly scheduled programme of vertebrae RSN, but the plain fact is that vertebrae are just not as good for lying down next to as scaps and humeri — though heaven knows we’ve done our best.)

Jensen’s second handicap was a tendency to figure fossils the way he thought they ought to be rather than how they actually were. For example, Jensen (1985:fig 2A) shows the very same Supersaurus cervical that Matt covered last week. Jensen’s version is influenced, we might charitably conclude, by a certain amount of imagination:

The taxonomic history of the various Supersaurus elements in Jensen’s specimen is baroque and Byzantine even by the standards of sauropod taxonomy, and I won’t go into it just now (again, stay tuned), but the result of all the to-ing and fro-ing is that a fair sample of elements is available (the cervical, two dorsals, a crushed sacrum, a handful of caudals, two scaps and pelvic elements). But many aspects of its anatomy remain obscure, and the most that can be said about its affinities is that it seems to be similar to, but distinct from, the diplodocine diplodocid Barosaurus.

No longer! As of six days ago, a new paper by Lovelace, Hartman and Wahl is — finally — out. It’s no exaggeration to describe this as one of the most eagerly awaited sauropod papers of the last decade, because it describes a brand new specimen of Supersaurus, WDC DMJ-021, from a quarry in Wyoming. It’s a little smaller than Jensen’s specimen, but very much in the same size class, that is, bigger than “Seismosaurus” and a lot bigger than any of the common-or-garden diplodocids you might see in museums, such as the Carnegie Diplodocus that seems to follow me around the museums of Europe. The paper contains some nice skeletal reconstructions (figs. 7-8 ) which show this well.

The new specimen consists of nine cervicals (in various conditions), six dorsals (ditto), nine or so caudals including the two most proximal, ribs, pelvic fragments and tibiae and fibulae. And here — tah-dah! — is the proximal caudal (lacking neural spine) in right lateral view, courtesy of Scott Hartman:

Take a moment to look at those scale bars, by the way. On my screen, if I blow the image up to full size, it’s roughly life-sized. Scroll around a bit and take in the topography. You may gulp a little if you wish. A certain amount of gasping may also be in order.

Lovelace et al. do a convincing job of showing that, while Supersaurus does resemble Barosaurus in gross proportions, it is in fact more closely related to Apatosaurus — a big surprise given that Apato is freakishly robust, and really stands alone among non-titanosaurian sauropods in terms of being absurdly over-engineered. As pointed out in the paper, however, this is more true in Apatosaurus excelsus and Apatosaurus louisae than in the type species, Apatosaurus ajax — and, indeed, if you check out the reconstruction of A. ajax in the frontispiece to Upchurch et al.’s (2005) monograph on a specimen of that species, you’ll notice that it’s not so crazy-fat as the Greg Paul apatosaur reconstruction we’ve all grown used to.

So what does this mean? For one thing, it means that Taylor and Naish’s (2005) rather obvious phylogenetic definition of Apatosaurinae as (Apatosaurus not Diplodocus) now has some substance to it, as the clade includes not only Apatosaurus but also Supersaurus and — it turns out, according to Lovelace et al’s analysis — Jerry Harris’s Suuwassea. The latter result is not wholly unexpected, as Jerry’s (2006a) abominable(*) paper on Suuwassea‘s axial skeleton did point out similarities to Apatosaurus, but this is the first time such a topology has been recovered by a published phylogenetic analysis, Jerry’s own (2006b) analysis having found Suuwassea as an unresolved basal flagellicaudatan in a trichotomy with Diplodocidae and Dicraeosauridae.

[(*) Why is the Jerry’s axial osteology paper “abominable”? Because it uses a nomenclatural system unique to a small group of workers consisting of, uh, Jerry, and is therefore near-incomprehensible to everyone who’s grown used to the standard Wilson (1999) nomenclature for vertebral laminae. If I had time to burn, I’d do a translation of Harris (2006a) and submit it to the Polyglot Paleontologist. Let me clearly say that, in other areas, I have nothing but respect for Jerry, whose work is both comprehensive and readable — a glorious combination — and whose reviews are the best and most useful I have ever seen. But this is one of those sad occasions when a very clever person has done a very dumb thing. I now await a rebuttal in the comments :-) ]

Another interesting consequence is that Apatosaurus‘s characteristically robust morphology now seems to be autapomorphic for the genus Apatosaurus itself, so that the ancestor of apatosaurines had a slender build, similar to that of Diplodocus, which was inherited by basal apatosaurines. It’ll be interesting to know what Jerry makes of this, and specifically how well Suuwassea fits this model.

One odd side-effect in the phylogeny of Lovelace et al. (2008:fig. 14) is that (Barapasaurus + Patagosaurus + (Mamenchisaurus + Losillasaurus)) form a clade, which is the outgroup to (Jobaria + Neosauropoda). Omeisaurus falls outside this group, which is a surprise as it has sometimes been thought congeneric with, or at least mixed up with, Mamenchisaurus. (Both Mamenchi and Omei have multiple species, all based on lovely material but described in only the most cursory fashion, and it’s thought that some species of each genus may belong in the other.) It’s not obvious why adding a deeply nested apatosaurine diplodocid diplodocoid should have such a dramatic effect on so much more basal a part of the tree, but that’s what happens. I’d like to hear thoughts on this.

Well, that’s enough for now, in what has become a much longer post than I intended. I finish by noting that Lovelace et al. also added “Seismosaurus” to their matrix, but found that not only did it clade with Diplodocus, it was scored identically! Accordingly, they concur with another recent paper that “Seismosaurus” is a junior subjective synonym of Diplodocus. In fact, they go further than that other paper did, and argue that poor old Sam is not just congeneric but conspecific with Diplodocus longus. That’s sort of sad — “Seismosaurus” was a pretty cool name. On the other hand, it does mean that NMMNH 3690 is the world’s biggest Diplodocus, and by some distance.

And finally, there are a couple of neat photos of a Supersaurus mount, based largely on the WDC specimen, over on Scott Hartman’s site. I recommend them. Strongly.

References

Unbelievably, despite the fact that it is one of my favorite places in the world, despite the fact that it is just 10 fast hours away by car, across some of the most desolate and beautiful country on the planet, I have not been to BYU since the fall of 2005.

The highlight of my last trip was spending a little quality time with the Dry Mesa Supersaurus cervical. You’ve seen it here before so you know it’s dimensions…sorta. As I am always saying, there is a big difference between knowing something in your head and knowing it in your gut. So here are a couple of gut-level facts about this vert.

First, it’s so darn big that once the forklift has it down from it’s shelf, it can’t turn or maneuver, and the driver has to crawl out through the window (true; I watched him do it). I have no idea how they got this thing up there in the first place. It’s not there anymore, it’s been moved to the gigantic shiny white new big bone storage room (a.k.a. the Vault of Awesome) that was just about completed when I was there last. How they moved it is another mystery, since the forklift can’t turn.

Second, if you want to get it all in one frame with minimal distortion, you have to get up on a very tall ladder and shoot straight down. Which I did. The scale bar is in cm (top) and inches (bottom).

This is one of my hand-full of favorite fossils in the world, and I’m looking forward to seeing it again in its new home. The barn it was in before was not air-conditioned, and the two hours I spent in there on a hot August afternoon had me sweating like a fat kid in a garbage sack. But it was more than worth it. Dirty is temporary. Science last forever (or close enough for me).

STOP THE PRESSES!! (May 7)

The paper describing the new Supersaurus specimen from Wyoming has finally been made public. It’s Lovelace et al., with a claimed date of 2007, which for all I know is when the thing actually came out. I’d appreciate details on that from those in the know. In any case, the paper is freely available by emailing co-author Scott Hartman on dinoboygraphics@aol.com – I haven’t even had a chance to read it yet, but I salute the authors for getting it out, and salute them for offering it to interested parties. Everyone should be so kind.

Those of you who have been paying attention to my recent posts will have pretty much known this was coming. I’d hate to disappoint you, so here it is:

Apatosaurus ajax NSMT-PV 20375, first caudal

What you’re looking at here is the first caudal vertebra (i.e. the first tail bone) of Apatosaurus ajax, the newish specimen NSMT-PV 20375 described by Upchurch et al. (2005). The drawings are all from the plates at the end of that lavishly illustrated paper: all I’ve done is composite them. The top row, from left to right, shows the vertebra in anterior, left lateral, posterior and right lateral views. Below the left lateral view is a dorsal view, with the front pointing to the left (as in the left lateral view).

Oddly, the size of this vertebra doesn’t seem to be stated in the paper, but two lines of evidence suggest that it’s about 65 cm in total height. First, measuring the caudal on the skeletal reconstruction that is the frontispiece, and comparing with that figure’s 1m scale-bar, yields a height of 64 cm; second, the neural spine’s height (measured from the ventral margin of the poztzygapophyses) is given in Table 9 as 392 mm, and that extrapolates, using the posterior view figure, to a total height of 665 mm. So about 65 cm, then.

The caudal vertebrae of diplodocids such as Apatosaurus, Diplodocus and Barosaurus are unusually complex for sauropods, having been somewhat “dorsalised”, i.e. taking on some of the complex morphology of posterior dorsals rather than being the rather dull round-centrum-with-a-flat-spine-on-top affairs you get hanging off the rear end of brachiosauruids. You’ll notice that the lateral processes, or “caudal ribs”, take the form of tall, broad plates, so that the middle part of the vertebra is trapezoidal in anterior view. This is as different as can be from the boring, stick-like caudal ribs of Brachiosaurus. (What actually are caudal ribs? So far as I can tell, amazingly, no-one really knows. They might be homologous with the diapophysis of dorsal vertebrae, or with the parapophysis, or perhaps both of them fused, or one or both fused with an actual rib.)

Oh, yes: also in the picture is your coccyx, that is, the four or five bones that make up your vestigial tail. It is, needless to say, contemptible. It’s surprisingly hard to find a reference for how big it should be, but by cross-scaling from illustrations of whole human skeleton and sacra, I’ve come up with a figure of about 2.5 cm, and that’s what I’ve used here. If you want to compare your tail with Apatosaurus‘s, remember that Apato had about eighty caudals: they diminish in size posteriorly, of course, but they do stay about the same anteroposterior length for much of the tail. In fact, diplodocids have tremendous tails, something like half the entire length of the entire animal. One of my long-standing bugbears is that the biomechanics of sauropod tails gets almost no attention (except for speculations about whip-cracking) compared with the love and care lavished on their necks. One day, one of us might do something about that.

That concludes our short but humiliating series of abuse directed at your frail human body. I’ll have to come up with something else next time it’s my turn. Hope you’ve enjoyed the ride.

Finally, good news for everyone who was intererested in Matt’s Aegyptosaurus post: he’s made a PDF of Stromer 1932 so you can see that mystery vertebra for yourselves.

Bibliography

  • Upchurch, Paul, Yukimitsu Tomida, and Paul M. Barrett. 2005. A new specimen of Apatosaurus ajax (Sauropoda: Diplodocidae) from the Morrison Formation (Upper Jurassic) of Wyoming, USA. National Science Museum Monographs No.26. Tokyo.

Aegyptosaurus lost

April 1, 2008

There seems to be some kind of bell curve associated with sauropods. We get lots of medium-sized ones, but very few babies, mostly disarticulated bits, and very few super-immense ones, which are also mostly disarticulated bits. Puertasaurus is known from two vertebrae. Sauroposeidon is known from 3.5. The holotype of Hudiesaurus is a single vertebra; the referred forelimb is not from the same individual or the same quarry, and there’s no particularly good reason to think it’s from the same taxon. Argentinosaurus is known from a handful of vertebrae and a smaller handful of limb bones.

Bruhathkayosaurus was evidently pretty big, but there’s only one paper on it so far, illustrated with very, um, simple line drawings of some bones and blurry non-orthogonal photos of others. More on that one later, maybe, although none of the preserved elements appear to be verts so it is a little outside our bounds. In any case, Bruhathkayosaurus may be the biggest sauropod known from remains that still exist (may be; by now you should know how much uncertainty that covers).

amphicoelias-altus-small.jpg

Then there are the really frustrating ones: the gigapods for which we have no remains left at all. What’s really frustrating is that these might be the biggest of all! The best known of our absent friends is Amphicoelias fragillimus, which Darren has discussed before and which we ought to cover here in the future. The genotype of Amphicoelias is the Diplodocus-sized A. altus, and it’s still around, or at least it was as of October 2006 because that’s when I took the photo above. No one knows what happened to the A. fragillimus vert. It might have gotten lost, or simply crumbled to dust since it was very fragile and it was excavated before the use of consolidant glues became widespread in paleontology (Carpenter 2006).

In the case of Aegyptosaurus, we know exactly what happened to the type material: it was blown to hell and gone, along with the original material of Spinosaurus and Carcharodontosaurus, when Allied bombs hit the museum in Munich in 1944. The type material of Aegyptosaurus baharijensis consisted of some caudal vertebrae and limb and girdle bones from an animal of unspectacular size. But in a curious parallel with Amphicoelias, there is–or rather was–a larger specimen, possibly one that represented a distinct species.

Near the end of the paper in which he described and figured A. baharijensis, Stromer (1932a) mentioned “ein Wirbel eines anderen noch größeren sauropod”, which he said would be described later. I’ll end the suspense right now: it wasn’t. Later that year Stromer published a short paper (1932b) on the sauropod fauna of Africa. That paper also did not describe any giant vertebrae in any detail, but it did include this photo (below).

stromer-vert-scan.jpg

The original caption reads “Professor Ernst Stromer neben einem Wirbel einer neuen Art von Aegyptosaurus“–Professor Ernst Stromer next to a vertebra of a new species of Aegyptosaurus. Presumably Stromer intended to provide a full description soon after, but it was not to be. The next summer at Bahariya Oasis he was attacked by a crocodile and nearly lost his left leg. In the end Stromer recovered, but only after repeated surgeries and many painful months spent learning to walk again. The wound effectively killed his professional career. Although he lived until 1952, his 1934 paper on Bahariasaurus was his last paleontological contribution. Almost all of the Bahariya Oasis collection was lost to science in 1944, but science lost Stromer himself almost a decade earlier.

So what about that vert? It’s clearly a posterior cervical. Stromer’s left hand is resting on the rib, which is awfully short and awfully high up on the centrum, which indicates that the vertebra is from near the base of the neck. There are other interesting features as well–note the hint of a keel on the bottom of the centrum, which is usually only found in fairly basal sauropods, and the ridges above the postzygapophyses, which put me in mind of Mamenchisaurus.

Also, I suppose you’ll have noticed that the vertebra is freakin’ immense. Frustratingly, neither Stromer nor the vert appear in their entirety, and neither are shown from an orthogonal angle (perils of using a portrait to try to do science, I know). Still, we know that Stromer was a tall man. Werner Janensch once playfully described him as “die bärtige Bohnenranke”–the bearded beanstalk. No one seems to have written down his exact height, and we’re missing his feet in this photo anyway, but from contemporary descriptions he seems to have been several inches over 6 feet. The diameter of the cotyle seems to be about the same as the distance between his shoulder and wrist, which is a good 2 feet in me and I’m only 6’2″. Assuming–well, you know–that would give a cotyle diameter of about 60 cm, which is just appallingly large. The cervico-dorsal vertebrae of the HM SII specimen of Brachiosaurus brancai are about 3/4 that big. Imagine B. brancai scaled up by a third.

It’s a cool thought, but that’s all it is. We don’t know exactly how tall Stromer was. We don’t know how much the vertebra might be foreshortened in this photo. It wouldn’t take much to get our imaginary monster sauropod downsized into being merely interesting instead of completely flabbergasting. And the specimen itself is literally history.

Farewell, Aegyptosaurus sp. We hardly knew you.

References

UPDATE

Okay, I’m pulling the plug on this one. It’s an April Fool’s Day post. Many of the biographical details about Stromer are just made up–he didn’t lose his leg in a crocodile attack, he did keep publishing after 1934, the giant Aegyptosaurus specimen is a Photoshopped cow vert. The ref for Stromer (1932b) is entirely fake–he never published a paper with that title. The fake paper was “supporting evidence” for the joke, and incorrect biographical details were tells that it was a sham. I’m telling all now because people are starting to look for the real Stromer (1932b), and although the joke had a good run, I hate wasting people’s time.