A sauropod on Mars

February 24, 2021

This is old news, for those who have been following NASA’s Perseverance rover since before it left Earth, and it’s also not my find–my friend, colleague, and sometime co-author Brian Kraatz send me a heads-up about it this morning.

NASA posted the image above a couple of days ago, in a post called “Mastcam-Z looks at its calibration target“. If you zoom in, you can just make out a tiny silhouette of a sauropod on the ring around the MarsDial (what we call a sundial on Mars).

Here’s a much clearer pre-launch image from the Planetary Society (link), which helped design the calibration targets. Starting at about 7:00 and going around clockwise, there’s an image of the inner Solar System, with the Sun, Mercury, Venus, Earth, and Mars, then DNA, bacteria, a fern, a sauropod, humans (same silhouettes as on the Pioneer probes), a retro-style rocket ship, and finally a motto, “Two worlds, one beginning”, which may be a sly nod to the hypothesis that life in the inner Solar System started on Mars and was later seeded to Earth on meteorites–or possibly vice versa.

What’s with all this bling? It’s all about calibrating the cameras on Perseverance. The MarsDial gives the position and angle of the sun, and the colored dots help calibrate the color output of the cameras. There are other calibration targets for other cameras on board Perseverance, as well as some other technological ‘Easter eggs’ from the folks who designed and built the rover–read more about them here (link).

Perseverance is up there to explore “the potential of Mars as a place for life” (source), both past and future. Its four science objectives are:

  1. Looking for Habitability: Identify past environments capable of supporting microbial life.
  2. Seeking Biosignatures: Seek signs of possible past microbial life in those habitable environments, particularly in special rocks known to preserve signs of life over time.
  3. Caching Samples: Collect core rock and “soil” samples and store them on the Martian surface. [For a future sample-return mission.–MJW]
  4. Preparing for Humans: Test oxygen production from the Martian atmosphere.

Personally, I have my fingers firmly crossed that Perseverance finds something like this sticking out of a Martian rock:

(That one is actually from Utah, not Mars–see this post.) I don’t see any other way that my particular skill set is going to contribute to the exploration of the Solar System, which I’d really like to do. So I’ll wait, and watch Perseverance send back pictures, and wait some more. Sigh.

Anyway, there’s at least one sauropod on Mars, and that will have to do (for now!).

Bonus: if you haven’t watched the video of the rocket skycrane delivering the car-sized Perseverance to the surface of Mars, you need to. And if you have watched it, who cares, watch it again:

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:

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.

What if I told you that when Matt was in BYU collections a while ago, he stumbled across a cervical vertebra — one labelled DM/90 CVR 3+4, say — that looked like this in anterior view?

I think you would say something like “That looks like a Camarasaurus cervical, resembling as it does those illustrated in the beautiful plates of Osborn and Mook (1921)”. And then you might show me, for example, the left half of Plate LXII:

And then you might think to yourself that, within its fleshy envelope, this vertebra might have looked a bit like this, in a roughly circular neck:

Reasonable enough, right?

But when what if I then told you that in fact the vertebra was twice this wide relative to its height, and looked like this?

I’m guessing you might say “I don’t believe this is real. You must have produced it by stretching the real photo”. To which I would reply “No no, hypothetical interlocutor, the opposite is the case! I squashed the real photo — this one — to produce the more credible-seeming one at the top of the post”.

You would then demand to see proper photographic evidence, and I would respond by posting these three images (which Matt supplied from his 2019 BYU visit):

BYU specimen DM/90 CVR 3+4, cervical vertebra of ?Camarasaurus in anterior view. This is the photo from which the illustration above was extracted.

The same specimen in anteroventral view.

The same specimen in something approaching ventral view.

So what’s going on here? My first thought was that this speicmen has to have been dorsoventrally crushed — that this can’t be the true shape.

And yet … counterpoint: the processes don’t look crushed: check out the really nice 3d preservation of the neural spine metapophyses, the prezygs, the transverse processes, the nice, rounded parapophyseal rami, and even the ventral aspect of the centrum. This vertebra is actually in pretty good condition.

So is this real? Is this the vertebra more or less as it was in life? And if so, does that mean that the flesh envelope looked like this?

Look, I’m not saying it isn’t ridiculous; I’m just saying this seems to be more or less where the evidence is pointing. We’ve made a big deal about how the necks of apatosaurines were more or less triangular in cross-section, rather than round as has often been assumed; perhaps we need to start thinking about whether some camarasaur necks were squashed ovals in cross section?

Part of what’s crazy here is that this makes no mechanical sense. A cantilevered structure, such as a sauropod neck, needs to be tall rather than wide in order to attain good mechanical advantage that can take the stress imposed by the neck’s weight. A broad neck is silly: it adds mass that needs to be carried without providing high anchors for the tension members. Yet this is what we see. Evolution doesn’t always do what we would expect it to do — and it goes off the rails when sexual selection comes into play. Maybe female camarasaurus were just really into wide-necked males?

Final note: I have been playing fast and loose with the genus name Camarasaurus and the broader, vaguer term camarasaur. Matt and I have long felt (without having made any real attempt to justify this feeling) that Camarasaurus is way over-lumped, and probably contains multiple rather different animals. Maybe there is a flat-necked species in among them?

(Or maybe it’s just crushing.)

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

Gilmore (1936:243) says of the mounted skeleton of Apatosaurus louisae CM 3018 in the Carnegie Museum that “with the skull in position the specimen has a total length between perpendiculars of about 71 feet and six inches. If the missing eighteen terminal caudal vertebrae were added to the tip of the tail, in order to make it conform to known evidence, the skeleton will reach an estimated length of 76 feet, 6 inches.” That’s 23.3 meters.

But what if it was 800 meters long instead? That would be 34.3 times as big in linear dimension (and so would mass 34.3^3 = 40387 time as much, perhaps a million tonnes — but that’s not my point).

What would a cervical vertebra of an 800m sauropod look like?

Gilmore (1936:196) gives the centrum length of CM 3018’s C10 as 530 mm. In our 34.3 times as long Apatosaurus, it would be 18.17 meters long. So here is what that would look like compared with two London Routemaster buses (each 8.38 meters long).

Cervical vertebra 10 of a hypothetical 800 meter long Apatosaurus louisae, with London Routemaster buses for scale. Vertebra image from Gilmore 1936:plate XXIV; bus image by Graham Todman, from Illustrations for t-shirts.

What is the research significance of this? None at all, of course. Still I think further study is warranted. Some look at sauropods that once were, and ask “why?”; but I go further; I look at sauropods that never were, and ask “why not?”

 

Xinjiangtitan when originally described, from Wu et al. (2013)

We’re way late to this party, but better late than never I guess. Wu et al. (2013) described Xinjiangtitan shanshanesis as a new mamenchisaurid from the Middle Jurassic of China. At the time of the initial description, all of the dorsal and sacral vertebrae had been uncovered, as well as a handful of the most posterior cervicals and most anterior caudals.

Xinjiangtitan revealed, from Zhang et al. (2018)

Jump a few years forward 2018, when Zhang et al. described the complete cervical series of Xinjiangtitan, based on further excavation of the holotype (they also changed some of the element identifications in the original description). It’s pretty insane: 

  • 18 cervical vertebrae, same as Mamenchisaurus youngi, and one less than M. hochuanensis, all discovered in articulation;
  • 10 of those vertebrae have centrum lengths of 1 meter or more;
  • the longest centrum, that of C12, is 123cm long;
  • the total lengths of the separate cervical vertebrae (not articulated) add up to about 15 meters;
  • even assuming that the condyles of the vertebrae were fully buried in the cotyles, the total length of articulated neck would still be 13.36 meters. 

Now, some caveating. Zhang et al. (2018) report two different lengths for most the cervicals: a maximum centrum length, which includes the anterior condyle, and a “minimum centrum length” without the anterior condyle. Reporting cervical lengths minus the condyle is fairly common–Janensch did it for what is now Giraffatitan (“ohne condylus”), McIntosh (2005) did it for the AMNH Barosaurus, Tschopp and Mateus (2017) did it for Galeamopus pabsti, and so on. In the freely available but as-yet-not-formally-published 4th chapter of my dissertation (Wedel 2007), I referred to the length without the condyle as the “functional length”, and I explicitly assumed that it was “the length that each vertebra contributes to the total neck length”. At the time I assumed that condyles were always fully buried in cotyles in life, because I didn’t know about camel necks (see Taylor and Wedel 2013b: fig. 21 and this post). 

Why am I bringing up all these minutiae? Because I’m really interested in the actual length of the neck of Xinjiangtitan in life, and that’s not so very straightforward to figure out. I’ll start with what Zhang et al. wrote, then proceed to their measurements, and then discuss their map.

At the start of the Description section, Zhang et al. (2018: p. 3) wrote:

In SSV12001, the cervical series is almost completely articulated and is exposed laterally (Figure 2). The long neck (at least 14.9 m) is well-preserved with a total of 18 cervical vertebrae. This measurement was estimated based on the maximum centrum length including the anterior condyles with the space for the cartilage assumed.

How much space is assumed for the cartilage? They don’t say, and it’s not clear, but one reading is that they just added up the total lengths of all the cervical centra and assumed that the cotyles were completely full of cartilage. Which is not so crazy as it might sound, since that’s exactly what happens in camels. But let’s see what their tables of measurements say.

Xinjiangtitan cervical vertebra measurements, from Zhang et al. (2018)

Table 1 gives the measurements of the atlas and axis, and Table 2 gives the measurements of all the remaining cervicals. Only “minimum centrum length”–without the condyle–is reported for cervicals 4 and 5, because C3-C5 were articulated as a unit, they haven’t been separated, and without CT scanning or further prep it’s going to be impossible to determine how long they were with the condyles. However, we can infer that the condyles of C4 and C5 are buried in the cotyles of C3 and C4 because (a) only the without-condyle lengths are reported, and (b) the condyles aren’t visible in the figures. File that away, it’s going to be important.

Adding up all of the max centrum lengths, including 165mm for the axis and 30mm for the atlas, per Table 1, I get a total of 14985mm, or 14.985 meters. Because Zhang et al. were so assiduous about their reporting–they really did Measure Their Damn Dinosaur–we can estimate pretty closely how much longer that total would be if it included the condyles of C4 and C5. Subtracting the min length from the max length, we find that the condyle is 70mm long in both C3 and C6, so it’s reasonable to assume the same for the vertebrae in the middle. Adding 140mm to the earlier total gets us up to 15125mm, or 15.125 meters. That’s assuming condyles end even with the rims of the cotyles, and cotyles are completely full of cartilage.

Xinjiangtitan cervicals, from Zhang et al. (2018: fig 3)

Adding up the all of the minimum centrum lengths, again including the axis and atlas, yields a total of 13360mm, or 13.36 meters. I think this smaller total is much more likely to be the actual length of the neck in life, for three reasons:

  1. As mentioned above, the condyles of C4 and C5 of this very specimen are actually buried in the cotyles of the preceding vertebrae. So we don’t need to add any space for cartilage to the summed minimum (without condyle) lengths–there certainly was cartilage between the surfaces of the condyles and cotyles, because that’s how intervertebral joints work, but there was not enough to push the condyles back outside the cotyles, unless we want to engage in some special pleading that C3-C5 were unnaturally smooshed together.
  2. Camels notwithstanding, having the condyles buried in the cotyles is pretty standard for articulated necks of big, long-necked sauropods. In the holotype specimens of Mamenchisaurus hochuanensis and Sauroposeidon, the condyles are not visible in lateral view, because they are completely buried in the cotyles of the preceding vertebrae–see the photos in this post and on this page to confirm that for yourself. In Giraffatitan, just the edges of the condyles are visible sticking out the backs of the cotyles in some of the posterior cervicals–see this post.
  3. The 13.36-meter neck is more consistent with the map of the specimen in the ground than either the 14.9-meter or 15.1-meter totals.

A little unpacking on that last point. Using the dorsal lengths from Wu et al. (2013: table 1)–and assuming that Zhang et al. are correct, and the D1 of Wu et al. is actually cervical 18, but D11 of Wu et al. is actually D10 and D11 together, so there are still 12 dorsals–I get a total length for the articulated dorsal column of 3355mm. Dividing 13360 by 3355 yields a cervical/dorsal ratio of 3.98. Using the screenshot of the map from Zhang et al. (2018: fig. 2), I measured 1505 pixels for the summed cervicals, 380 pixels for the summed dorsals, and 112 pixels for the scale bar. Assuming the scale bar is supposed to be 1 meter (and not 20 meters or 2.0 meters as it is labeled) yields a summed cervical length of 13.4 meters, a summed dorsal length of 3.39 meters, and a cervical/dorsal ratio of 3.96–all admirably close, off by no more than 4cm across 16+ meters, if the neck in the ground was articulated condyle-inside-cotyle. If we assume the map shows a 14.9-meter neck, then both the dorsal series and the scale bar are off by about 12%, which is unreasonable given the high precision of the map if the articulated neck corresponds to the summed minimum lengths.

Mounted skeleton of Omeisaurus tianfuensis: N E C C

Bonus observation #1: the holotype of Mamenchisaurus hochuanensis has a cervical/dorsal ratio of 3.52, but in Omeisaurus tianfuensis the same ratio is 4.09. So Xinjiangtitan is actually a little shorter-necked than Omeisaurus, at least compared to the length of the dorsal series.

Bonus observation #2: the 123-cm cervical of Xinjiangtitan is only the fifth-longest vertebra of anything to date:

  1. BYU 9024, possibly referable to Supersaurus or Barosaurus: 137cm
  2. Price River 2 titanosauriform: 129cm
  3. OMNH 53062, Sauroposeidon holotype: 125cm
  4. KLR1508-77-2, Ruyangosaurus giganteus referred specimen: 124cm
  5. SSV12001, Xinjiangtitan shanshanesis holotype: 123cm
  6. MPEF-PV 3400/3, Patagotitan holotype: 120cm (+?)
  7. MPM 10002, Puertasaurus holotype: 118cm

Getting pretty crowded there in the 120s, but then a big jump to BYU 9024. I’ll have more to say on that in a second.

Just to put a bow on this section, I’m pretty confident, based on all available measurements, taphonomic evidence, and the consilience between the measurements and the map, that the holotype individual of Xinjiantitan had a neck 13.36 meters (43 feet, 10 inches) long in life. 

That’s stunning.

By comparison, the second- and third-longest complete cervical series (of anything, ever, to date) belong to Mamenchisaurus hochuanensis, at 9.5 meters (Young and Zhao 1972, and confirmed by Mike in a basement in Slovenia), and Giraffatitan at 8.5 meters for MB.R.2181 (the larger XV2 specimen would have had a 9.6-meter neck).

Some other contenders, from Taylor and Wedel 2013a (fig 3)

There were things with longer necks, for sure, but none of those necks are complete (yet). Mamenchisaurus sinocanadorum is estimated to have had a neck about 12 meters long, based on the partial cervical series of the holotype. I know there are skeletal reconstructions out there with longer necks, and I will believe them as soon as the specimens they are based on are published. In the aforementioned dissertation chapter, I estimated 11.5 meters for the neck of Sauroposeidon, assuming a brachiosaurid-like cervical count of 13. Note that Mannion et al. (2013) recovered Sauroposeidon as a somphospondyl, and a cervical count of 15 or more as a synapomorphy of Somphospondyli. Adding a couple more 1.2-meter mid-cervicals would bring Sauroposeidon up to perhaps 14 meters. The longest cervicals of Patagotitan are in about the same size class, and we don’t know the cervical count in that monster, either.

BYU 9024, with the mounted (cast, composite) skeleton of Brachiosaurus altithorax and one Mike Taylor for scale

And of course, lurking out there in crazy neck-space is BYU 9024, the immense cervical originally referred to Supersaurus, but which more likely belongs to Barosaurus, and an ungodly huge one. That critter might–might–have had a 17-meter neck.

And I gotta say, in light of Xinjiangtitan, that no longer seems so unreasonable. Because Xinjiangtitan was a big sauropod but not a monster. The dorsal length of 3.3 meters and the femur length of 1.65 meters put it in roughly the same size category as the bigger individual of Jobaria (DL 3.2m, FL 1.8m) or the AMNH 5761 Camarasaurus supremus (DL 2.5m, FL 1.8m). Let’s imagine a Xinjiangtitan with a 2.4-meter femur, the size of Patagotitan or Argentinosaurus. Assuming isometric scaling, that individual would have a 2.4/1.65 = 1.45 x 13.36 = 19.4-meter neck. 

Do we really think such animals never existed?

Food for thought: the holotype individual of Xinjiangtitan was small enough to be buried as a complete skeleton. What about the individuals that were too big to bury in one shot?

Utterly unsurprising, but still nice to see: the highly pneumatic internal structure of the vertebrae of Xinjiangtitan, from Wu et al. (2013)

References

It’s been a minute, hasn’t it?

Up top, C10 and C11 of Diplodocus carnegii CM 84, from Hatcher (1901). Below, C9 and C10 of Apatosaurus louisae CM 3018, from Gilmore (1936). The Diplodocus verts are in right lateral view but reversed for ease of comparison, and the Apatosaurus verts are in left lateral view. Both sets scaled to the same cumulative centrum length. Just in case you forgot that apatosaurines are redonkulous.

References

  • Hatcher, John Bell. 1901. Diplodocus (Marsh): its osteology, taxonomy, and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63.
  • Gilmore, Charles Whitney. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300.

On 22nd December 2020, I gave this talk (via Zoom) to Martin Sander’s palaeontology research group at the University of Bonn, Germany. And now I am giving it to you, dear reader, the greatest Christmas present anyone could ever wish for:

It’s based on a 2013 paper written with Matt Wedel, which itself goes back through many years slow gestation, originating in a discussion on a car journey in 2008. I must tell the full story some time; but not this time.

In this talk, I start by showing in a hopefully vivid way how very much longer sauropods’ necks were than those of any other animal. Then I explain six of the features that made those very long necks possible: no constraint on vertebral count; small, light heads that did not process food; absolutely large bodies with a quadrepedal bauplan; an avian-style respiratory system; air-filled cervical vertebrae; and elongated neck ribs.

If you want to know more, see that Wedel and Taylor (2013) paper!

Finally, my thanks to René Dederichs, a Student of Paleontology in Martin Sander’s work group at the University of Bonn. He organized this event, and recorded the talk for me.

References

 

Cool URIs don’t change

November 26, 2020

It’s now 22 years since Tim Berners-Lee, inventor of the World Wide Web, wrote the classic document Cool URIs don’t change [1]. It’s core message is simple, and the title summarises it. Once an organization brings a URI into existence, it should keep it working forever. If the document at that URI moves, then the old URI should become a redirect to the new. This really is Web 101 — absolute basics.

So imagine my irritation when I went to point a friend to Matt’s and my 2013 paper on whether neural-spine bifurcation is an ontogenetic character (spoiler: no), only to find that the paper no longer exists.

Wedel and Taylor (2013b: figure 15). An isolated cervical of cf. Diplodocus MOR 790 8-10-96-204 (A) compared to D. carnegii CM 84/94 C5 (B), C9 (C), and C12 (D), all scaled to the same centrum length. Actual centrum lengths are 280 mm, 372 mm, 525 mm, and 627 mm for A-D respectively. MOR 790 8-10-96-204 modified from Woodruff & Fowler (2012: figure 2B), reversed left to right for ease of comparison; D. carnegii vertebrae from Hatcher (1901: plate 3).

Well — it’s not quite that bad. I was able to go to the web-site’s home page, navigate to the relavant volume and issue, and find the new location of our paper. So it does still exist, and I was able to update my online list of publications accordingly.

But seriously — this is a really bad thing to do. How many other links might be out there to our paper? All of them are now broken. Every time someone out there follows a link to a PalArch paper — maybe wondering whether that journal would be a good match for their own work — they are going to run into a 404 that says “We can’t run our website properly and can’t be trusted with your work”.

“But Mike, we need to re-organise our site, and —” Ut! No. Let’s allow Sir Tim to explain:

We just reorganized our website to make it better.

Do you really feel that the old URIs cannot be kept running? If so, you chose them very badly. Think of your new ones so that you will be able to keep then running after the next redesign.

Well, we found we had to move the files…

This is one of the lamest excuses. A lot of people don’t know that servers such as Apache give you a lot of control over a flexible relationship between the URI of an object and where a file which represents it actually is in a file system. Think of the URI space as an abstract space, perfectly organized. Then, make a mapping onto whatever reality you actually use to implement it. Then, tell your server.

If you are a responsible organization, then one of the things you are responsible for is ensuring that you don’t break inbound links. If you want to reorganize, fine — but add the redirects.

And look, I’m sorry, I really don’t want to pick on PalArch, which is an important journal. Our field really needs diamond OA journals: that is, venues where vertebrate paleontology articles are free to read and also free to authors. It’s a community-run journal that is not skimming money out of academia for shareholders, and Matt’s and my experience with their editorial handling was nothing but good. I recommend them, and will proabably publish there again (despite my current irritation). But seriously, folks.

And by the way, there are much worse offenders than PalArch. Remember Aetogate, the plagiarism-and-claim-jumping scandal in New Mexico that the SVP comprehensively fudged its investigation of? The documents that the SVP Ethics Committee produced, such they were, were posted on the SVP website in early 2008, and my blog-post linked to them. By July, they had moved, and I updated my links. By July 2013, they had moved again, and I updated my links again. By October 2015 they had moved for a third time: I both updated my links, and made my own copy in case they vanished. Sure enough, by February 2019 they had gone again — either moved for a fourth time or just quietly discarded. This is atrocious stewardship by the flagship society of our discipline, and they should be heartily ashamed that in 2020, anyone who wants to know what they concluded about the Aetogate affair has to go and find their documents on a third-party blog.

Seriously, people! We need to up our game on this!

Cool URIs don’t change.

 

 


[1] Why is this about URIs instead of URLs? In the end, no reason. Technically, URIs are a broader category than URLs, and include URNs. But since no-one anywhere in the universe has ever used a URN, in practice URL and URI are synonymous; and since TBL wrote his article in 1998, “URL” has clearly won the battle for hearts and minds and “URI” has diminished and gone into the West. If you like, mentally retitle the article “Cool URLs don’t change”.

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:

  1. 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).
  2. If you don’t have any red-cyan glasses, get some!