October 15, 2010
This post is nearly three weeks late — it’s based on a piece of artwork that appeared on 25 September, and which I wanted to write about immediately. But it got washed away in the flood of camel necks (which by the way is not over yet), and then in the festival of articular cartilage, then by the whole “Amphicoelias brontodiplodocus” thing and the subsequent discussion of amateurs in palaeo, and then by what was already an overdue announcement of my sauropod history paper and the attendant copyright nonsense. So it’s been a stupidly busy time here at SV-POW! Towers, but now the air has cleared a little, and it’s time to look at this beauty:
This would be a beautiful piece of art by any standards — the world can always use brachiosaur art! — but what makes this extra special for me is that it is the first ever life restoration of my very own brachiosaur, BHM R5937, the Tendaguru specimen known as The Archbishop. It’s by SV-POW! regular Nima, and I am absolutely delighted to see it. It’s very Greg Paul-like, and I mean that in the most positive sense. (I may not be a fan of Greg’s taxonomic vicissitudes, but his art is just beautiful.)
Over on his blog, Nima has described in detail how he created this piece, and shows four progressively refined versions (of which the one above is the last) — I urge you to check it out if you’re interested in art, brachiosaurs or both.
Nima’s blog-post also includes a brief history of the Archbishop, mostly taken from my 2005 SVPCA talk. It’s a good summary, but I do have a few comments to make. (I typed a lot of this in as a comment to the original post, but Blogger ate my comments as usual.)
- The specimen is not known as M23, and has never been — that is in fact the designation of the Tendaguru quarry from which is was excavated. Paul (1988) mistakenly conflated the quarry name with a specimen number, and referred to this specimen as BMNH M23, and Glut’s (1977) encyclopaedia perpetuated the error, but it’s always been R5937.
- “The giant Brachiosaurus finds of the Germans” are now, of course, Giraffatitan.
- “Controversy lingered” — well, no, not really. The problem was worse than that: no-one paid a blind bit of notice to the specimen before 2004.
- “It turns out the double spine claim was totally bogus and unscientific” — well, we don’t really know that yet. It’s certainly true that none of the prepared vertebrae (five cervicals, two complete dorsals and an additional dorsal spine) have bifid spines; but Migeod reported these from the anterior dorsals, and it’s not clear that we have those. A fair bit of material remains in jackets, and more has probably been lost or destroyed. So it is possible, if unlikely, that one day we’ll open one of those jackets and find good evidence for bifid spines.
- “Close-up of the Archbishop vertebrae (doesn’t look much like the mitre of an archbishop to me, but who knows” — well, the name The Archbishop is not based on any resemblance of the bones to a mitre. (Nor is it based on anything else. It’s completely arbitrary.)
Last 0f all, what about the actual picture? Well, the long, thin, snakelike neck is beautiful art, but I don’t think it’s great science. The height of the cervicals that we have for this animal show that the neck would have had to be quite a bit dorsoventrally taller than shown here. And because there were only 13 cervical vertebrae — 12 if you omit the atlas, which is really a whole nother kettle of badgers, a neck bent into a strongly sigmoid pose like this would exhibit noticable kinks at some of the intervertebral joints — as you can see in giraffes when they twist their necks.
That aside, though, this is great. Again, I am really delighted that it’s out there. Congratulations to Nima!
June 28, 2010
For reasons that seemed good to me at the time, I took my best shot at photographing the right cervical rib from cervical vertebra 3 of my ostrich, Veronica [see earlier Part A, Part B and Part C for context]. I thought you might like to see the result, so here it is:
For some reason, cervical ribs don’t seem to get a lot of love in the literature: the only paper I know that figures them in half-decent detail is Osborn and Mook’s classic (1921) monograph on Camarasaurus, and even there, the job is done in rather a half-hearted fashion. I’m planning to buck this trend by properly figuring the cervical ribs of the Archbishop when I finally get around to finishing that paper, and I included a sneak preview of the rib that I’ve arbitrarily designated X1 a while back. It’s instructive to compare that illustration with this one. In fact, here it is again:
Update (the next day)
It occurs to me that I should have composed the ostrich-cervical-rib illustration in the same orientation and order as the Archbishop one, for easier comparison. So that’s what I’ve done below. Since the Archbishop rib X1 is from the left side, I’ve also flipped the right-sided ostrich rib to match. Here it is:
February 12, 2010
Since I started taking photographs of sauropod vertebrae back in 2004, I’ve got much, much better at it, and for the last few months I’ve been meaning to write an article about what I’ve learned along the way. A few weeks ago, fellow SV-POW!er Ranger Matt Wedel posted an article on his 10 Minute Astronomy blog on how to photograph the moon through binoculars, and that served as a prod to get back into blogging gear in the post-Christmas season.
Before I launch in, let me be really clear that I am not a proper photographer — not at all. I don’t even know what an F-stop is or what Single Lens Reflex means. Probably I should invest some time into learning some of this, since specimen photographs are so important in the world of sauropod vertebrae. (After all, the specimens are more than a little cumbersome to loan, so photos often have to stand as proxies for the actual specimens.) Nevertheless, what I’ve learned in the last five or six years has got me to the point where I am producing much, much better specimen photographs than when I started, and I hope at least some of you can benefit from what I’ve learned.
First up, get a decent camera. However skilled you are, you can’t take better photos than the hardware allows. Although I am to blame for the composition above and for some of blurriness, the over-exposure, poor definition and artifacts are the fault of the camera. I was using a truly horrible camera back then — some super-cheap list-of-features-on-a-discount-website piece of kit.
The good news is that a “decent” camera doesn’t need to break the bank: for our purposes you don’t need to spend a fortune on professional-photographer standard equipment. I am looking on ebay right now, and it seems you can get my model of camera for £100 in the UK or $150 in the US (second-hand of course) which is a level of investment we really should be prepared to put into one of the most important aspects of descriptive work.
What constitutes a decent camera? Mostly, optics. These days, every camera has more than enough megapixels for most purposes, so you can just forget about that statistic altogether. It’s about the quality of the lens and the size of the CCD — those are the factors that determine how much information the camera can capture, and if it puts out more bits than that, then all it’s doing is wasting disk-space and bandwidth.
Can I justify the claim that all modern cameras have enough megapixels? I think so. Suppose you’re preparing a full-page plate for the Journal of Vertebrate Paleontology. In practice, plates are nearly always composites of several photos, but suppose you want a single shot filling the whole plate. The printable area of a JVP page is 182 x 233 mm, which is 7.2 x 9.2 inches. At 300 dpi, that’s 2161 x 2752 pixels, which is 5947072, or a slice under 6 megapixels. So 6 Mp is enough for a full-page plate. (For what it’s worth, my camera does 2272 x 1704 = 3.8 megapixels, and I have never found myself feeling a need for more resolution.)
For the same reason, you definitely want optical zoom rather than digital zoom, which really amounts to just blowing up the image.
Another big win: get a spare battery, so that one can be recharging while you’re using the other. If you don’t do that, your camera is out of commission half the time.
And get a big enough memory card. What’s “big enough”? For me, that means enough space to hold a whole day’s images so I can do a single dump onto the laptop in the evening, rather than having to keep stopping to transfer. I can take maybe a maximum of 300 photos a day. With 1 Mb images, that means I need a 300 Mb card, which is chickenfeed. You literally can’t buy cards that small any more, so this is not really a factor these days and I might just as well not have mentioned it. (The reason I did mention it is that my camera originally came with a 16 Mb card or something similarly stupid, which meant ten minutes or so of photography before downloading.)
Get the specimen in frame
Shoot from cardinal directions
Don’t put anything in front of the specimen
Use a plain background when possible.
But the good news is that all these problems can be ameliorated if you follow the last and most important rule in this section which is:
Take many shots and keep only the good ones
I remember reading once, long ago, that the single biggest factor in the difference of quality between a professional photographer’s work and an amateur’s is that the pro takes ten times as many shots and throws 90% of them away. In these days of digital cameras with huge memory cards, we can all make like professionals now. When Matt and I were at the Field Museum in Chicago, we took 168 photos of those Brachiosaurus dorsals alone. Of those, maybe a dozen or so are really worth keeping. But at least I have those dozen.
In general, I take every photograph twice. As I’ve got better at taking the photos, I am increasingly finding that both come out well and it’s a toss-up which to keep, but maybe one time in ten or twenty, one of them just doesn’t come out right — something is wrong with the focus, or the camera shakes, or something — and that’s when I’m glad I have the spare.
On the other hand, my camera’s built-in flash is pretty lame. Expensive flash units might do much better.
As with flash, it seems that the only thing to do is try photos with and without external lights, and with the lights in various different positions, and see what comes out best.
So what can you do? Well, there are several levels of compensation.
Simply being aware of remaining still
When I have to hold the camera in my hands and I know it’s going to be a long exposure I find myself going into a sort of zen state — I become aware of my heartbeat and try to time the shutter release so that the camera doesn’t get moved by my pulse. It’s error-prone, but at least being aware of it can help.
Brace against a door-frame or similar
The combination of tripod mounting and shutter delay means that you can get good exposure in almost any light.
… And finally …
From: Carol Brown<firstname.lastname@example.org>
We just posted an article, “100 Best (Free) Science Documentaries Online” (http://www.onlineuniversities.com/blog/2010/01/100-best-free-science-documentaries-online/). I thought I’d drop a quick line and let you know in case you thought it was something you’re audience would be interested in reading. Thanks
January 31, 2010
I hope you have a pair of 3D glasses. If you do, then check this baby out:
(This is of course the same vertebra that we last saw in a multi-view composite figure at the end of the Brachiosaurus coracoid post.)
I’ve started to get into the habit recently of photographing some specimens from two slightly different angles: I couldn’t tell you exactly how much rotation I use, but I would guess it’s something like three to five degrees. That’s because I’ve found that flipping back and forth between the two images can give a useful sense of depth. If you don’t believe me, here are two not-quite-identical photos of the Archbishop’s Cervical S: open each of them in a tab, then flick back and forth between them:
It had occurred to me a while back that, just for fun, it would be interesting to composite them into a red-cyan 3D image. But I was prodded into action by two things. First, the free Lego marketing magazine that my boys get sent every month arrived, and with it a freebie pair of cheap cardboard red-cyan glasses. And second, Matt published a steropair of moon images on his blog. Matt’s friend Jarrod is a professional digital effects artist — in fact he’s won Emmies for stuff like blowing up Los Angeles for 24 — and threw together an anaglyph from the moon pictures. I got instructions from Jarrod on how to do this, and was gratified how easy it was. Here you go:
- Open the two photos as two layers of a single image.
- Using the Colour Levels dialogue, turn the red channel of one of the photos all the way down to zero (so that it appears in shades of cyan)
- Using the same dialogue, turn both the blue and green channels of the other photo down to zero (so that it appears in shades of red)
- Change the Layer Mode of the top layer to Brighten Only
That’s it, you’re done! Save the resulting composite image as a JPEG and upload it to your sauropod-vertebra blog. Jarrod uses PhotoShop; I use the Gimp, which is a free more-or-less equivalent program — the same technique works fine with both.
If I was pleasantly surprised at how simple the technique is, I was astounded at the quality of the result. I’d expected all the colour of the image to be gone, and to see a vague monochrome haze. Instead, I saw rock-solid 3D in full colour — truly informative images that convey the morphology of complex bones far better than any published figure I’ve ever seen. Seriously, go get your red-cyan glasses, you won’t regret it.
Here is another anaglyph of the same vertebra, in posterior view close-up, showing in detail what looks suspiciously like a hyposphene below and between the postzygs. (If this is indeed a hypophene, then I believe it’s unique among sauropods.)
Journals have occasionally published stereopair images of palaeo specimens: small images a couple of inches wide, next to each other, which you can supposedly see as a single 3D image if you cross your eyes in just the right light provided the wind is from the southeast — personally, I have never been able to see these things, thought Matt can. But these big, full-colour 3d images are orders of magnitude more information.
I’ve never seen one in a journal, in part of course because colour printing is such an insanely expensive luxury. But as Matt says, we all live in the future now, and I hope that’s about to change. I will be sending the Archbishop description, when it’s done, to PLoS ONE, which because of its electronic-only format can include any number of full-colour figures at no cost. I plan to send a few anaglyphs among the more conventional figures. Fingers crossed that they make it into the published version — I guess if I get a traditionalist reviewer, he might think these are frivolous and demand that I remove them. But they are not frivolous: they may be the most informative figures I have ever prepared.
Finally, I leave you with our old friend the pig skull, from all the way back in Things To Make And Do part 1 — but this time in glorious 3D!
January 27, 2010
[Hello to any redditors who have followed a link here. Please scroll down to find the more interesting articles; sorry that your introduction to SV-POW! is a backlink article.]
Excuse the self-promotion, but some SV-POW! readers might be interested to know that I have an Ask Me Anything going over at the social news aggregator site reddit com. I posted a long comment on someone else’s submission on whale size, and a lot of people asked me questions, so I started a separate thread, which you can read here.
I seem to be at the top of the IAMA page:
January 25, 2010
In my not-long-quite-so-recent-any-more paper on Brachiosaurus and Giraffatitan, I gave as one of the autapomorphies of Brachiosaurus proper that the glenoid articular surface of its coracoid is laterally deflected. Although we’ve discussed this a little in comments on SV-POW!, it’s not yet made it into one of our actual articles. I hestitated to feature it here since it’s so darned appendicular, but in the end I concluded that it was too interesting and potentially important to overlook.
So here it is!
The deflected surface is most apparent in the posterior view at the right of the fiigure, in which it appears deflected about 55 degrees from the horizontal. That’s misleading, though — partly because the shape is more complex in three dimensions than can be easily visualised from these orthogonal shots, and partly because of course the coracoid was not held perfectly vertical in life. In fact, the orientation of the coracoid in sauropods, and of the entire shoulder girdle, remains rather controversial. It’s not an area I’ve got involved in so far, but this Mystery Coracoid Of Weirdness (hereafter MCOW) might just be my gateway into the wacky world of pectoral girdles.
The ventral view at the bottom of the figure is also informative: as you can see from that angle, the articular surface extends a long way laterally (i.e. towards the top of the figure in this orientation). Once you’ve got your eye in with those images, it’s easy to see the facet in the lateral-view photo, despite the less than ideal saturated lighting: it’s shaped like a raindrop falling towards bottom left. (Well, not really: raindrops are actually vertically flattened spheroids rather then raindrop-shaped, but that’s not the point.)
Observations and interpretations on this oddity will be very welcome.
Finally, here is your regularly scheduled sauropod vertebra:
December 29, 2009
Yes, you too can have your very own brachiosaurid cervical! Specifically, “Cervical P” of the as-yet unnamed brachiosaur NHM R5937, informally known as “The Archbishop”. Here is is!
(All images of the vertebra are copyright the NHM.)
All you need is scissors, glue, and this handy cut-out-and-keep schematic. You’ll want to click through to the full-resolution version (which if I say it myself is a thing of some beauty.)
Print this out, then cut around the black lines to make the template:
Then fold downwards along all the grey lines:
Now, just glue the tabs, fold the lines at right angles, and stick the box together.
The very last tab you glue will be the most difficult to get right, because you won’t be able to press the two parts together once the box is closed. So make sure that you glue the long side of the blank base last, as it doesn’t matter so much if that’s not don’t cleanly.
And there is the final result, this time in the opposite view:
And that’s all there is to it!
December 22, 2009
Ever since we started working on Sauroposeidon, Rich Cifelli and I dreamed of seeing the reconstructed neck on display. That vision has come to fruition.
The Oklahoma Museum of Natural History opened a totally new building in 2000. Coincidentally, the opening ceremony for the new digs was held the same week that the paper naming Sauroposeidon came out in JVP. The exhibits in the new building were pretty cool right out of the gate, but the exhibit people have not been idle, and if you haven’t been there in a year or three you will find many things that you have not seen before.
My favorite upgrade is the new orientation gallery, which introduces museum visitors to the functions of the museum and the kinds of work that go on in the research wing, including most of the traditional -ologies. The reconstructed neck and head of Sauroposeidon hang from the ceiling, spanning most of the length of the gallery and extending out into the museum’s great hall.
The beast was reconstructed by Research Casting International. I got to visit their workshop in Ontario, Canada, a little over a year ago to see how things were coming along. The people there were extremely serious about getting things right (how refreshing!). We spent quite a while talking about how Sauroposeidon was different from Giraffatitan (RCI remounted the Humbolt dinos) and sketching out what the missing bits might have looked like, especially the skull.
Of course we don’t have any skull material from Sauroposeidon, but we do have skulls and partial skulls from several other basal titanosauriforms. Together with one of the people working on the Sauroposeidon project, I filled up a couple of pieces of paper with sketches showing what a slender mid-Cretaceous brachiosaur might have looked like. In particular, and in keeping with the gracility of the cervical vertebrae, we narrowed the skull a bit to get rid of the dreaded Giraffatitan Toilet-Bowl Head.
The completed neck and head were already mounted in the OMNH when I visited last Christmas, but the gallery wasn’t open yet so all I got–and all I could pass on to you–was this teaser. The new orientation gallery opened in the middle of this spring, so Sauroposeidon has been hanging out there for a while. This is just the first chance I’ve gotten to go see my baby.
What a fine present. Merry Christmas from the SV-POW!sketeers!
Update from Mike
Here is my Christmas card to you all.
December 2, 2009
It’s a strange thing, but no-one seems to bother properly figuring their sauropods’ cervical ribs — that is, the long, thin, posteriorly directed ribs of the neck vertebrae. I’ll be bucking that trend when the Archbishop paper comes out, but to get your mouth watering ahead of time, here is the head of the cervical rib that I have arbitrarily designated X1, the largest of those preserved in the Archbishop:
The top image shows the rib in anterior view, with dorsal pointing to the left; the middle row shows the rib with anterior pointing upwards, in (from left to right), lateral, dorsal, medial and ventral views; the bottom row shows posterior view, again with dorsal to the left. Click through the image to see the full glory of the high-resolution version. Remember folks: you only get this sort of high-resolution image published in PLoS journals!
As I mentioned, sauropod cervical ribs have been pretty comprehensively ignored in the literature. I can’t offhand think of a single paper about them (unless you count Martin et al.’s (1998) proposal that they functioned in ventral compression-bracing of sauropods’ necks, and let’s not even start on that), and I am really struggling to think of paper that figures them. Even the usually super-reliable Osborn and Mook (1921) dropped the ball here, with a single illustration (out of 127 figures) and single short paragraph of text (out of 141 pages). Here it is:
Janensch (1950) did discuss the cervical ribs of Giraffatitan in some detail, but his figures are not very informative. If anyone knows of better treatments of sauropod cervical ribs in the literature, then please mention it in the comments!
Because of this poor coverage in the published record, it’s hard for me to compare the Archbishop cervical ribs with those of other taxa. For example, the medial view of X1 (in the middle of the “cross” in the image above) shows that the internal face of the cervical rib loop, where the cervical rib reaches up to articulate with the diapophysis of its vertebra, has two parallel struts of bone extending vertically with a narrow groove between them. Is that unusual? I have no idea.
(I do have photos of some other Tendaguru cervical ribs, referred to Giraffatitan – although if I’m right that the Archbishop is not Giraffatitan, so that there are multiple brachiosaurs in the Tendaguru Formation, then who knows whether that referral is correct?)
Finally, we come to the matter of your cervical ribs. I would have liked to do this post as one in the Your Noun Is Adjective series, but the brutal truth is, you don’t even have any cervical ribs — unless you are one of the lucky 0.2% that, according to the Wikipedia article, have a supernumary rib which is frankly just an additional dorsal rib (uh, thoracic rib I guess) that’s growing out of your last cervical vertebra by mistake. (Wikipedia’s horrible humanist bias is apparent here, in that the article doesn’t even mention the fact that plenty of other animals have cervical ribs and love them.)
Anyway, here’s how human cervical ribs look, stolen from Do You Really Need Back Surgery? A Surgeon’s Guide to Neck and Back Pain and How to Choose Your Treatment:
- Janensch, Werner. 1950. Die Wirbelsaule von Brachiosaurus brancai. Palaeontographica (Suppl. 7) 3:27-93.
- Martin, John, Valérie Martin-Rolland, and Eberhard (Dino) Frey. 1998. Not cranes or masts, but beams: the biomechanics of sauropod necks. Oryctos 1:113-120.
- Osborn, Henry Fairfield, and Charles C. Mook. 1921. Camarasaurus, Amphicoelias and other sauropods of Cope. Memoirs of the American Museum of Natural History, n.s. 3:247-387, and plates LX-LXXXV.
November 24, 2009
I drew a couple of these a while back, and I’m posting them now both to fire discussion and because I’m too lazy to write anything new.
Here’s the neck of Apatosaurus, my own reconstruction based on Gilmore (1936), showing the possible paths and dimensions of continuous airways (diverticula) outside the vertebrae.
Here’s figure 4 from Lovelace et al. (2007), which first got me thinking about pneumatic traces on the ventral surfaces of the centra and what they might imply. You can see pneumatic spaces between the parapophyses in Supersaurus (A) and Apatosaurus (C) but not in Barosaurus (B).
This is another of my moldy oldies, again based on one of Gilmore’s pretty pictures, showing how I think the soft tissues were probably arranged. The muscles are basically the technicolor version of Wedel and Sanders (2002). Two points:
- How bulky you make the neck depends mainly on how much muscle you think was present (which of course depends on how heavy you think the neck was…). Here I was just trying to get the relationships right without worrying about bulk, but it’s worth considering.
- The volume of air inside the vertebra was dinky compared to the probable volume of air outside. In Apatosaurus, either of the canals formed by the transverse foramina has almost twice the cross-sectional area of the centrum.
A fair amount of this has been superseded with better data and prettier pictures by Schwarz et al. (2007), so don’t neglect that work in any ensuing discussion (it’s free, fer cryin’ out loud). And have a happy Thanksgiving!
- Gilmore, C.W. 1936. Osteology of Apatosaurus with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11: 175-300.
- Lovelace, D.M., Hartman, S.A., and Wahl, W.R. 2007. Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny. Arquivos do Museu Nacional, Rio de Janeiro 65(4):527-544.
- Schwarz, D., Frey, E., and Meyer, C.A. 2007. Pneumaticity and soft−tissue reconstructions in the neck of diplodocid and dicraeosaurid sauropods. Acta Palaeontologica Polonica 52 (1): 167–188.
- Wedel, M.J., and Sanders, R.K. 2002. Osteological correlates of cervical musculature in Aves and Sauropoda (Dinosauria: Saurischia), with comments on the cervical ribs of Apatosaurus. PaleoBios 22(3):1-6.
Mike asked me to add the labeled version of Nima’s brachiosaur parade, so here you go. Click to embiggen.