Xenoposeidon in glorious 3D
June 27, 2014
Get your red/cyan anaglyph glasses on, and feast your eyes:
Click through for stupidly high resolution.
Those of you who are still too cheap to have sprung 99¢ for a pair of glasses, you can make do with this grossly inferior wigglegram:
Got this in my inbox this morning. I presume this means that the 30 days start now. But if you’re interested in this stuff, don’t tarry.
And you should be interested in this stuff. This volume brings together some very active and knowledgeable researchers–including our fellow SV-POW!sketeer, Darren Naish, and sometime coauthor Dave Hone–writing on a broad range of interesting topics under the umbrella of behavior.
These animals experienced days less than 23 hours long, and years with close to 400 days.
A beautiful Lego Diplodocus skeleton
June 18, 2014
Check out this beautiful Lego Diplodocus:
(Click through for the full image at full size.)
I particularly like the little touch of having of bunch of Lego Victorian gentleman scientists clustered around it, though they’re probably a bit too big for the skeleton.
This is the work of MolochBaal, and all rights are reserved. You can see five more views of this model in his Flickr gallery. I especially admire how he’s managed to get the vertebral transitions pretty smooth, the careful use of separate radius/ulna and tibia/fibula, and the use of a transparent brick in the skull to represent the antorbital fenestra.
The forefeet are wrong — their toes should not be splayed out — but you can’t blame MolochBaal for that, as he was copying the mounted CM 84/94 cast in the Madrid museum.
Brian Engh is unleashing monsters
June 16, 2014
We feature a lot of Brian Engh’s stuff here–enough that he has his own category. But lately he has really been outdoing himself.
The wave of awesome started last year, when Brian started posting videos showing builds and suit tests for monsters–monster suits, monster puppets, monster you-name-its. Like this monster-sculpting timelapse from last August:
And this suit test from last October:
Brian even wrote a blog post about how he builds monsters.
Things really ramped up this May with the release of “In Mountains”, the first video in a three-part series from Brian’s Earth Beasts Awaken album (which is badass, and available for free here).
If you’re thinking that the Mountain Monster has some Estemmenosuchus in its background, you are correct–that astonishing real-world critter was one of Brian’s inspirations, among many others.
More awesomeness is coming in July, when the next video, “Call to Awaken”, is slated to be released. Here’s a teaser:
I have even more exciting Brian-Engh-related news, but I am not at liberty to discuss that just yet. Hopefully sometime this fall. Stay tuned, true believers. UPDATE: Now I’m at liberty to discuss it!
Mounted skeleton of Emeus crassus
June 16, 2014
In a back room at the Field Museum, from my visit in 2012.
I took a lot of photos of the neck, which nicely records the transition in neural spine shape from simple to bifurcated–a topic of interest to sauropodophiles.
In a couple of weeks (in the early afternoon of 25 June), I’ll be speaking at ESOF 2014 (the EuroScience Open Forum) in Copenhagen, Denmark. The session I’m part of is entitled “Should science always be open?“, and the irony is not lost on me that, as that page says, “You must be registered and signed in to download session materials.”
So here is the abstract for my talk — one of four in the session, to be followed by an open discussion.
Yes, of course science should always be open!
“If I have seen further it is by standing on the shoulders of giants”, said Isaac Newton. Since the earliest days of science, progress has always been achieved by the free exchange and re-use of ideas. Understanding this, scientists have always leaned in the direction of openness. Science outside of trade secrets and state secrets has a natural tendency to be open.
Until recently, the principle barrier to sharing science has been the logistic difficulty of printing and distributing copies of papers. The World Wide Web was originally designed to solve precisely this problem. By making research freely available worldwide, the Web doesn’t just change how well we can do things, it changes what we can do. As Cameron Neylon has observed, at network scale you achieve serendipity by design, not by blind luck. At a time when the world is in dire need of scientific breakthroughs, the removal of barriers and use of content-mining promises progress in health, climate, agriculture and other crucial areas.
So it’s nothing short of tragic when publishers — whose job it is to make research public — purposely erect barriers that prevent this. The iniquity of paywalls is not just that they prevent citizens from accessing work their taxes pay for. Much more fundamentally, paywalls deliberately destroy the incredible value that the Web creates.
Openness is indispensable simply because the opportunity cost not being open is appalling and incalculable. Publishers must find business models that don’t break science, or they must go away.
The idea is to present this as slickly as possible in ten minutes, in a “TED-like” format. I might try to make a video of it here at home once I have it all straight in my mind, and all the slides done.
How heavy was Giraffatitan brancai? I mean, really?
June 9, 2014
We’ve touched on this several times in various posts and comment threads, but it’s worth taking a moment to think in detail about the various published mass estimates for the single specimen MB.R.2181 (formerly known as HMN SII), the paralectotype of Giraffatitan brancai, which is the basis of the awesome mounted skeleton in Berlin.
Here is the table of published estimates from my 2010 sauropod-history paper, augmented with the two more recent estimates extrapolated from limb-bone measurements:
| Author and date | Method | Volume (l) | Density (kg/l) | Mass (kg) |
|---|---|---|---|---|
| Janensch (1938) | Not specified | — | — | `40 t’ |
| Colbert (1962) | Displacement of sand | 86,953 | 0.9 | 78,258 |
| Russell et al. (1980) | Limb-bone allometry | — | — | 13,618 |
| Anderson et al. (1985) | Limb-bone allometry | — | — | 29,000 |
| Paul (1988) | Displacement of water | 36,585 | 0.861 | 31,500 |
| Alexander (1989) | Weighing in air and water | 46,600 | 1.0 | 46,600 |
| Gunga et al. (1995) | Computer model | 74,420 | 1.0 | 74,420 |
| Christiansen (1997) | Weighing in air and water | 41,556 | 0.9 | 37,400 |
| Henderson (2004) | Computer model | 32,398 | 0.796 | 25,789 |
| Henderson (2006) | Computer model | — | — | 25,922 |
| Gunga et al. (2008) | Computer model | 47,600 | 0.8 | 38,000 |
| Taylor (2009) | Graphic double integration | 29,171 | 0.8 | 23,337 |
| Campione and Evans (2012) | Limb-bone allometry | — | — | 35,780 |
| Benson et al. (2014) | Limb-bone allometry | — | — | 34,000 |
(The estimate of Russell et al. (1980) is sometimes reported as 14900 kg. However, they report their estimate only as “14.9 t”; and since they also cite “the generally accepted figure of 85 tons”, which can only be a reference to Colbert (1962)”, we must assume that Russell et al. were using US tons throughout.)
The first thing to notice is that there is no very clear trend through time, either upwards or downwards. Here’s a plot of mass (y-axis) against year of estimate (x-axis):
I’ve not even tried to put a regression line through this: the outliers are so extreme they’d render it pretty much useless.
In fact, the lowest and highest estimates differ by a factor of 5.75, which is plainly absurd.
But we can go some way to fixing this by discarding the outliers. We can dump Colbert (1962) and Alexander (1989) as they used overweight toys as their references. We more or less have to dump Russell et al. (1980) simply because it’s impossible to take seriously. (Yes, this is the argument from personal incredulity, and I don’t feel good about it; but as Pual (1988) put it, “so little flesh simply cannot be stretched over the animal’s great frame”.) And we can ignore Gunga et al. (1995) because it used circular conic sections — a bug fixed by Gunga et al. (2008) by using elliptical sections.
With these four unpalatable outliers discarded, our highest and lowest estimates are those of Gunga et al. (2008) at 38,000 kg and Taylor (2009)at 23,337. The former should be taken seriously as it was done using photogrammetrical measurements of the actual skeletal mount. And so should the latter because Hurlburt (1999) showed that GDI is generally the least inaccurate of our mass-estimation techniques. That still gives us a factor of 1.63. That’s the difference between a lightweight 66 kg man and and overweight 108 kg.
Here’s another way of thinking about that 1.63 factor. Assuming two people are the same height, one of them weighing 1.62 times as much as the other means he has to be 1.28 times as wide and deep as the first (1.28^2 = 1.63). Here is a man next to his 1.28-times-as-wide equivalent:
I would call that a very noticeable difference. You wouldn’t expect someone estimating the mass of one of these men to come up with that of the other.
So what’s going on here? I truly don’t know. We are, let’s not forget, dealing with a complete skeletal mount here, one of the very best sauropod specimens in the world, which has been extensively studied for a century. Yet even within the last six years, we’re getting masses that vary by as much as the two dudes above.
Dry Mesa Brachiosaurus cervical in dorsal view
June 8, 2014
This is BYU 12867–you’ve seen it here before–in dorsal view. It’s not a brilliant shot–I took it through the glass of the display case while filming a documentary at the North American Museum of Ancient Life in Lehi, Utah, in 2008. Centrum length is 94 cm, total length with the overhanging prezygapophyses is over a meter.
How much is our intuition about sauropod mass worth?
June 5, 2014
As promised, some thoughts on the various new brachiosaur mass estimates in recent papers and blog-posts.
Back in 2008, when I did the GDI of Giraffatitan and Brachiosaurus for my 2009 paper on those genera, I came out with estimates of 28688 and 23337 kg respectively. At the time I said to Matt that I was suspicious of those numbers because they seemed too low. He rightly told me to shut up and put my actual results in the paper.
More recently, Benson et al. (2014) used limb-bone measurements to estimate the masses of the same individuals as 56000 and 34000 kg. When Ian Corfe mentioned this in a comment, my immediate reaction was to be sceptical: “I’m amazed that the two more recent papers have got such high estimates for brachiosaurs, which have the most gracile humeri of all sauropods“.
So evidently I have a pretty strong intuition that Brachiosaurus massed somewhere in the region of 35000 kg and Giraffatitan around 30000 kg. But why? Where does that intuition come from?
I can only assume that my strongly held ideas are based only on what I’d heard before. Back when I did my 2008 estimate, I probably had in mind things like Paul’s (1998) estimate of 35000 kg for Brachiosaurus, and Christiansen’s (1997:67) estimate of 37400 for Giraffatitan. Whereas by the time the Benson et al. paper came out I’d managed to persuade myself that my own much lower estimates were right. In other words, I think my sauropod-mass intuition is based mostly on sheer mental inertia, and so should be ignored.
I’m guessing I should ignore your intuitions about sauropod masses, too.
References
- Benson Roger B. J., Nicolás E. Campione, Matthew T. Carrano, Philip D. Mannion, Corwin Sullivan, Paul Upchurch, and David C. Evans. (2014) Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage. PLoS Biology 12(5):e1001853. doi:10.1371/journal.pbio.1001853
- Christiansen, Per. 1997. Locomotion in sauropod dinosaurs. Gaia 14:45-75.
- Paul, Gregory S. 1998. Terramegathermy and Cope’s Rule in the land of titans. Modern Geology 23:179-217.
- Taylor, Michael P. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806.