Various Internet rumours have suggested that the Archbishop is a super-giant sauropod one third larger than the mounted Giraffatitan specimen MB.R.2181 (formerly HMN SII). This is incorrect.

Figure E. Skeletal inventory of NHMUK PV R5937, “The Archbishop”, showing which bones were excavated by Migeod’ expedition. Based on a skeletal reconstruction of Giraffatitan brancai kindly provided by Scott Hartman: note that this image does not illustrate the shapes or proportions of the Archbishop material. Bones prepared and available for study are shown in white; those still in jackets awaiting preparation in light grey; those excavated by Migeod but apparently lost or destroyed in dark grey.

Migeod’s assessment of the size of the animal was based on the vertebrae: “The [neck] vertebrae found give a 20-foot [6.10 m] length […] The length of the back including the sacral region was about 15 feet [4.57 m]. The eight or nine caudal vertebrae cover about 6 feet [1.83 m]” (Migeod 1931a:90). This gives the total preserved length of the skeleton as 41 feet (12.50 m). By comparison, Janensch (1950b:102) gives lengths of portions of the mounted skeleton of MB.R.2181 as 8.78m (neck), 3.92m (torso) and 1.07m (sacrum) for a torso-plus-sacrum length of 4.99m. On this basis, the preserved neck of NHMUK PV R5937 is only 69% as long as that of MB.R.2181, but since the first four vertebrae were missing and omitted from Migeod’s measurement, this factor cannot be taken at face value. More informative is the torso-plus-sacrum length, which in NHMUK PV R5937 is 92% the length of MB.R.2181.

This is consonant with measurements of individual elements, which compare as follows:

Table 4. Comparative measurements of Archbishop and Giraffatitan elements

ElementMeasurement (cm)ArchbishopGiraffatitanRatio
Torso plus sacrumtotal length4574990.916
C10 (mC4)centrum length991000.990
C11 (mC3)centrum length104100[1]1.040
D4 (mD3)centrum length27360.750
Longest riblength over curve2352630.894
Left scapulocoracoidlength over curve221238[2]0.929
Right humeruslength1462130.685
Right humeruswidth51590.864
Right iliumlength98123[3]0.797
Right iliumheight7996[4]0.823
Femurlength122196[5]0.622
Average0.846

Archbishop measurements taken from Migeod (1931a) and converted from imperial; Giraffatitan measurements are for MB.R.2181 except where noted, and are taken from Janensch (1950a:44) and Janensch (1961).
Notes.
[1] Janensch (1950a) did not report a total centrum length for C11, as its condyle had not been removed from the cotyle of C10; but since the length of its centrum omitting the condyle was, at 87 cm, identical to that of C10, it is reasonable to estimate its total length as also equal to that of C10.
[2] Janensch (1961:181) did not include measurements for the right scapula of MB.R.2181, which is incorporated into the mounted skeleton, but does give the proximodistal length of its right coracoid as 45 cm. Using the 193 cm length given for the similarly sized scapula Sa 9, we can deduce a reasonable total estimate of 238 cm for the scapulocoracoid.
[3] Estimated by Janensch (1950b:99) based on cross-scaling from the fibula and ilium of Find J from the Upper Saurian Marl.
[4] This is the measurement provided by Janensch (1961:199) for the ilium Ma 2, which is incorporated into the mounted skeleton, and which Janensch (1950b:99) considered to match MB.R.2181 very precisely.
[5] Based on a restoration of the midshaft which Janench (1950b:99) calcuated based on other finds.

Individual lines of this table should each be treated with caution: Migeod’s measurements may have been unreliable, and in any case are underspecified: for example, we do not know whether, when he gave a vertebra’s length, he included overhanging prezygapophyses or the condyle. Similarly, we know that Migeod (1931:96) wrote that a rib “was as much as 92.5 inches long”, but we do not know for certain that, like Janensch, he measured the length over the curve rather than the straight-line distance between the ends. And when Migeod says that the ilium “measured 38.5 by 31 inches” we do not know that the height was measured “at the public process”, as Janensch (1961:199) specified.

With those caveats in place, nevertheless, a picture emerges of a sauropod somewhat smaller than MB.R.2181, though by no means negligible. On average, the measurements come out about 15% smaller than those of Giraffatitan.

But this average conceals a great deal of variation. The cervical vertebrae are comparable in length to those of MB.R.2181 (The total of 203 cm for C10 and C11 in the Archbishop, only 1.5% longer than 200 cm for MB.R.2181, is a difference well within the margin of measurement error). The Archbishop’s scapulocoracoid may have been 93% as long as in MB.R.2181. But the limb bones are signficantly shorter (87% for the humerus and a scarcely credible 62% for the femur), and the humeri at least bseem to be have been proportionally more robust in the Archbishop: only 2.86 times as long as wide, whereas the ratio is 3.61 in MB.R.2181. If Migeod’s measurements can be trusted, we have here an animal whose neck is as long as that of Giraffatitan, but whose limbs are noticably shorter. These proportions corroborate the hypothesis that the Archbishop is not a specimen of Giraffatitan.

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!

Well, one reason is the utterly rancid “block editor” that WordPress has started imposing with increasing insistence on its poor users. If there is one thing that world really doesn’t need, it’s a completely new way of writing text. Seriously, WordPress, that was a solved problem in 1984. As Henry Spencer very nearly said back in the eighties, “thy creativity is better used in solving problems than in creating beautiful new impediments to productivity“.

But enough pointless whining: instead, check out this bad boy:

Taylor (in prep. for 2020: Figure V). NHMUK PV R5937, “The Archbishop”, cervical vertebra V (most anterior preserved cervical vertebra, probably C6), left side still encased in plaster. A. Reconstruction of right lateral view with neural spine, prezygapophysis, diapophysis, condyle, cotyle and cervical rib restored. The prezygapophysis from the succeeding vertebra that has adhered to this element is shown in red. B. Dorsal view with anterior to the right. C. Posterior view. D. Right lateral view. E. Anterior view. F. Ventral view with anterior to the right. Scale bar 20 cm.

Yes, it’s your friend and mine, The Archbishop! It’s a big titanosauriform sauropod excavated by F. W. H. Migeod for the British Museum (Natural History) back in 1930, from the same Tendaguru Formation that yielded the awesome Giraffatitan specimens in the Museum für Naturkunde Berlin.

Yes, I admit I have been working on the Archbishop for more than sixteen years, and that I gave a talk about it at SVPCA 2005, and that I failed utterly to get it done as part of the Paleo Project Challenge 2010, and that as early as 2011 I was in despair about ever finishing it, and that I promised to do it by SVPCA 2016 but didn’t.

But in 2018 I did something significant, which was to actually start writing the paper in public. Now anyone can follow the progress of the project — and it’s progressing. The manuscript currently runs to about fifty printed pages, although that length is inflated by twenty-odd beautiful illustrations — of which the “Cervical V” image above is just one. (Do click through to see it in all its glory.)

So, yeah. That’s the main reason I am not blogging much. Because I am writing the paper. Finally.

I know, I know — you never believed this day would come. And who could blame you? Nearly thirteen years after my 2005 SVPCA talkSweet Seventy-Five and Never Been Kissed, I am finally kicking the Archbishop descriptive work into gear. And I’m doing it in the open!

In the past, I’ve written my academic works in LibreOffice, submitted them for peer-review, and only allowed the world to see them after they’ve been revised, accepted and published. More recently, I’ve been using preprints to make my submitted drafts public before peer review. But there’s no compelling reason not to go more open than that, so I’ll be writing this paper out in the open, in a public GitHub repository than anyone can access. That also means anyone can file issues if they thing there’s something wrong or missing, and anyone can submit pull-requests if they have a correction to contribute.

I’ll be writing this paper in GitHub Flavoured Markdown so that it displays correctly right in the browser, and so that patches can be supported. That will make tables a bit more cumbersome, but it should be manageable.

Anyway, feel free to follow progress at https://github.com/MikeTaylor/palaeo-archbishop

The very very skeletal manuscript is at https://github.com/MikeTaylor/palaeo-archbishop/blob/master/archbishop-manuscript.md

Here I am at SVPCA in 2015. I am haunted by the fact that ten years ago at SVPCA 2005, I gave a talk about the NHM’s Tendaguru brachiosaurid, NHMUK R5937. And the description is still not done and submitted a full decade later. Even though it’s objectively one of the most beautiful specimens in the world:

dorsals-ab-composite

So here is my pledge to the world:

By this time next year (i.e. the start of SVPCA 2016 in Liverpool), I will have written and submitted this description. If I fail, I give you all permission — no, I beg you — to mock me mercilessly. Leave mocking comments on this blog, yes; but more than that, those of you at SVPCA are invited to spend the week pointing contemptuously at me and saying “Ha!”

Let’s hope it doesn’t come to that.

Update (6 September): see also.

Illustration talk slide 32

Illustration talk slide 33

Illustration talk slide 34

The links in the first slide:

Mike’s post on desaturating the background in specimen photos is here, and previous posts in this series are here.

Today (12th February) is the one-year anniversary of the first PeerJ papers! As Matt put it in an email this morning:

Hard to believe it’s been a year already. On the other hand, it’s also hard to believe that it’s only been a year. PeerJ is just such an established part of my worldview now.

That’s exactly right. PeerJ has so completely rewritten the rule-book (on price, speed and quality of service) that now when I’m thinking about new papers I’m going to write, the question I ask myself is no longer “Where shall I send this?” but “Is there any reason not to send it to PeerJ?”

dorsals-ab-composite

Dorsals A and B (probably D8 and D9) of NHM R5937, “The Archbishop”, a still-undescribed brachiosaurid sauropod from the Upper Jurassic Tendaguru Formation of Tanzania, which I will get done this year, and which is destined for PeerJ. Top row: dorsal view with anterior to the right. Bottom row, from left to right: left lateral, posterior, right lateral, anterior.

Yesterday in the comments of a post on The Scholarly Kitchen, Harvey Kane asked me “I am curious as to where you get the notion that publishing OA is less expensive and in some way “better” than the traditional model?” My reply was (in part):

My notion that OA publishing yields better results than traditional is rooted in the online-only nature of articles, which allows them to ignore arbitrary limits on word-count, number of figures, use of colour, etc., and to exploit online-only formats such as video, 3d models, CT-slice stacks, etc. In my own field of vertebrate palaeontology, it’s now routine to see in PLOS ONE descriptive articles that are many times more comprehensive than their equivalents in traditional journals — see for example the recent description of the frog Beelzebufo.

Of course there is nothing specific to open-access about this: there is no technical reason why an online-only subscription journal shouldn’t publish similarly detailed articles. But my experience so far has been that they don’t — perhaps because they are tied to the mindset that pages and illustrations are limited resources.

For Beelzebufo in PLOS ONE, read baby Parasaurolophus in PeerJ, which we described as “the world’s most open-access dinosaur“. This paper is 83 pages of technicolour goodness, plus all the 3d models you can eat. And the crazy thing is, this sort of detail in descriptive papers is not even exceptional any more — see for example the recent description of Canardia in PLOS ONE, or this analysis of croc respiration in PeerJ

Years ago, I said that in the Archbishop descriptions I wanted to raise the bar for quality of illustration. Well, I’ve taken so long over getting the Archbishop done that the bar has been raised, and now I’m scrambling to catch up. Certainly the illustrations even in our 2011 description of Brontomerus are starting to look a bit old-fashioned.

And of course, the truly astonishing thing about PeerJ is that it does this so very cheaply. Because I’m already a member (which cost me $99), the Archbishop description is going to be free to me to publish this year. (This year for sure!) If we also get our Barosaurus neck preprint published properly this year,then I’ll have to find $100 to upgrade my Basic membership to Enhanced. That’s cheap enough that it’s not even worth going through the hassle of trying to get Bristol to pay for me. And if I ever hit a year when I publish three or more papers, I’ll upgrade once more (for another $100) to the Investigator plan and then that’s it: I’m done paying PeerJ forever, however many papers I publish there. (Matt jumped straight to the all-you-can-eat plan, so he wouldn’t even have to think about it ever again.)

Barosaurus lentus holotype YPM 429, Vertebra Q (C?13). Top row: left ventrolateral view. Middle row, from left to right: anterior view, with ventral to the right; ventral view; posterior view, with ventral to the left. Bottom row: right lateral view, inverted. Inset shows diapophyseal facet on right side of vertebra, indicating that the cervical ribs were unfused in this individual despite its great size. Note the broad, flat prezygapophyseal facet visible in anterior view. (Taylor and Wedel 2013b: figure 6)


Barosaurus lentus holotype YPM 429, Vertebra Q (C?13). Top row: left ventrolateral view. Middle row, from left to right: anterior view, with ventral to the right; ventral view; posterior view, with ventral to the left. Bottom row: right lateral view, inverted. Inset shows diapophyseal facet on right side of vertebra, indicating that the cervical ribs were unfused in this individual despite its great size. Note the broad, flat prezygapophyseal facet visible in anterior view. (Taylor and Wedel 2013b: figure 6)

PeerJ’s pricing is making PLOS ONE’s $1350 APC look distinctly old-fashioned; and the $3000 charged by the legacy publishers (for a distinctly inferior product) is now frankly embarrassing. You might expect that as such low prices, PeerJ’s quality of service would suffer, but that’s not been our experience: editing, reviewing, typesetting and proofing for our neck-anatomy paper were all up there with the best we’ve received anywhere.

And it’s great to see that it’s not just minor researchers like Matt and me who are persuaded by PeerJ: they’ve now accumulated a frankly stellar list of 20 universities (so far) with institutional plans for researchers to publish there. When I say “stellar” I mean that the list includes Harvard, MIT, Cambridge, Berkeley, Stanford, Johns Hopkins, UCL, Carnegie Mellon, Duke … the list goes on.

We can only hope that the next year, and the next ten and twenty, are as successful for PeerJ as the first has been; and that other New Generation publishers will join it in pushing the field forward.

I leave the last word to Matt:

I’m getting Vicki a lifetime membership for Valentine’s Day. Because I’m a romantic.

She’s a lucky, lucky woman.

Illustration talk slide 9

Illustration talk slide 10

Illustration talk slide 11

Illustration talk slide 12

That link in the first slide will take you here, and the rest of the series is here.

Generally when we present specimen photos in papers, we cut out the backgrounds so that only the bone is visible — as in this photo of dorsal vertebrae A and B of NHM R5937 “The Archbishop”, an as-yet indeterminate Tendaguru brachiosaur, in right lateral view:

DSCN7651-desaturated-whiteBut for some bones that can be rather misleading: they may be mounted in such a way that part of the bone is obscured by structure. For example — and this is a very minor case — the ventral margins of the centra in the photo above are probably slightly deeper than they appear, because the centra are slightly sunk within the plinth that holds the vertebrae upright.

So I’ve been toying with a different idea: instead of cutting the background out completely, leaving it in place but toning it down. Then the supporting structure is visible, but clearly distinct from the actual bone. (For a more extreme case, see the “Apatosaurusminimus sacrum.)

Here’s how the image above looks if I desaturate the background:

DSCN7651-desaturated

I’m not sure what to make of this. It looks a bit strange to me, but that might only be the strangeness of unfamiliarity.

And it might not work so well (or indeed it might work better) for photos taken against a busier background.

What do you think?

The Magi present gifts to the Christ child