The biggest of the big

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I don't know if that grabs your attention, but sorting out the size of giant sauropods sure grabs mine. Let's take a more detailed look at some of the critters in this image:

First off, I need to admit that this is not all inclusive. The legendary Amphicoelias fragillimus will never be included (unless more material is found). I have not sufficiently nailed down the scaling of Argentinosaurus yet to include it, but early scaling makes it look like it's the same size or slightly smaller than Puertasaurus (which I did include).

Note that most of these animals are only known from a single specimen (and often quite incomplete skeletons at that), which means that we don't really know what the size range of animals was in a living population. So keep in mind that while we can compare individual specimens, we can't say with any certainty that the biggest skeleton really came from the biggest sauropod species.

Here are some other quick hits:

1) For personal reasons I love me some Supersaurus. I've scaled the reconstruction to the size of the WDC specimen (32m), though the type specimen may have reached 34m in length. Either way it's the longest sauropod we can reasonably restore, though it certainly was not the heaviest (diplodocids tend to be fairly slab-sided compared to titanosaurs).

2) The large NMMNH Diplodocus specimen (originally named Seismosaurus) is also very long (~30m) but probably even lighter in mass.

3) Diplodocids may rule the roost in length, but macronarians seems to (mostly) crush them in terms of mass. Puertasaurus is currently my reigning champion; filling in the (extensive) missing elements with other lognkosaur relatives leads to a 27 meter long animal that is clearly the heaviest of the group (I'll speculate maybe in the 60-70 tonne range, but treat that as arm waving until it's verified by volumetric or double integration analysis).

4) To elaborate on preliminary Argentinosaurus results (not included above), it’s in the same size range as Puertasaurus, but basal titanosaurs may have had somewhat shorter tails (hence the smaller length) and the vertebrae aren't quite as wide as Puertasaurus, so my best guesstimate is that it loses on both accounts to it's lognkosaur relative, if only by a weeeee bit.

5) I didn't include Paralititan but I did scale it (hey, there's only so much space). It's large, but appears to be somewhat smaller than the Dallas specimen of Alamosaurus.

6) Speaking of Alamosaurus, I spent a lot of time trying to sort out who had the biggest fragmentary remains between Fowler & Sullivan (2010) and Guzman-Gutierrez & Palomino-Sanchez (2006). The tibia from Mexico is easily biggest (see gray silhouette behind the main Alamosaurus), but foreground skeletal here is based on Fowler and Sullivan's largest specimen (an isolated tail vertebrae) which happens to be from animal almost exactly the same size as the specimen on display at the Perot Museum of Nature and Science. Of course at this point we don't know for sure if the mexican tibia is truly Alamosaurus, or something new.

6) Brachiosaurus has long been abandoned in discussions of who is the largest dinosaur, but I'm not sure that's a good idea. The skeletal above is restored to the size of the type specimen, but some of the Utah specimens may be larger. The very broad-gutted Puertasaurus ekes out a larger size, but with such small sample sizes I don't think Brachiosaurus can actually be ruled out at the species level.

7) On the other hand, the significantly less robust Giraffatitan probably can be ruled out despite being quite tall.

8) While titanosaurs are generally heavier than diplodocids, very large Apatosaurus specimens appear to fit comfortably in the same size class. In addition to the Oklahoma specimen I have seen a few other (unpublished) apatosaur specimens that at least rival it in size.

So there you have it. If you have any other questions hit me up in the comments section below.

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Check out the Walking with Dinosaurs movie trailer, with "my" dinosaurs

I know, it's not exactly an earth-shaking post on anatomy or reconstructing prehistoric life, but as I mop up some of the duties that have taken me away from blogging the last few months I thought I'd share this trailer, which shows off some of what took time away from blogging last year at this time:

I know that some will object to the anthropomorphization of the dinosaurs' actions, but actually a ton of time was spent on trying to develop less mammalian behaviors and expressions that would still read to an audience. In the end not all of them worked out, but the realities of such a project are that no movies with this sort of budget will get made if they people fronting the cash think audiences won't be able to relate to it.

I think the anatomy will be some of the best ever seen on the silver screen. The compositing and color in one or two of the shots don't look as good as say the Jurassic Park movies, but with a final release not coming until holidays in 2013 I seriously doubt the entire film has been through final color grading, so I wouldn't let that bother you.

What do you guys think?

P.S. I was only one of the anatomy designers - Mark Witton was the other major designer that I know of (that is, created anatomical creature design illustrations as well as consulted), although there was an impressive assortment other paleontologists consulting on the project. After the 2D design was done the talented David Krentz added greatly to the character designs while transferring our work into the realm of three dimensions.

Even after models are made a project like this depends on an army of incredibly talented artists, including those who paint the models, the technical directors and riggers who make it so those static models can move, and the animators who bring them to life. The finished look also strongly depends on the texture and render artists, including shader development, digital lighting, and the people who composite and color grade the finished imagery. I only use the term "my" to illustrate enthusiasm for having played a role, not to imply that the role was more than a cog in a large and very talented army of people who worked on the project.

Massive changes incoming to diplodocid sauropod stance

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I know it's been a while since I posted anything, and luckily I have a backlog of content to share in the coming weeks, but I'm so excited about this project that I felt I had to post this, if for no other reason than as a warning to artists out there that are thinking about restoring sauropods in the near future. In particular diplodocoids - think "therizinosaur" and you'll be on the right track. I can't say too much until the paper clears embargo later this week, but all of the oddities we see in diplodocoids will make a lot more sense, including the massive upcurve in the tail. It also nicely links Taylor et al's work on neck posture with Emily Giffin's older work on reduced forelimb innervation in Apatosaurus.

More as soon as the journal will allow it!

Edit: Well it's April 2nd, and I'm going to have a post on this prank up in the next day or two, but in case you are landing on this page from an external source I wanted to clarify that it was indeed an April Fool's prank.

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Giant theropods: North vs South

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Ok, wading into the always contentious issue of who was the biggest (which on 'teh internetz' seems to loosely translate into "who was more awesome?") I'm presenting my analysis of the always popular Tyrannosaurus vs Giganotosaurus issue.

A few things worth noting:

1) It appears that the type specimen of Giganotosaurus is essentially the same size as Sue despite having a somewhat longer femur. This is sort of surprising, since T. rex is generally thought of as having longer legs (in reality Sue simply has a proportionately longer lower leg relative to her upper leg, not longer legs overall).

2) We really don't know which of the two was longer, as there is enough of a margin of error in restoring tail lengths that the margin of error could allow either one to eek out a "who's the longest" win here (we're ignoring other theropods for the time being). A good discussion on this topic can be found here: [link]

3) Sue almost certainly had a higher mass than the Giganotosaurus type specimen, as tyrannosaurs seem to have broader torsos for their size.

4) So...that large isolated Giganotosaurus jaw? It's not really clear how much bigger that individual is, because there isn't perfect linear scaling between it and the type specimen (the isolated jaw is proportionately a bit deeper). My "best fit" version appears above, and indicates an animal about 6.5% longer than the type. THat would result in an animal over 13 meters in length, and also one that would be heavier than Sue.

5) Yes, I know there are also fragments of even larger T. rex specimens. Unfortunately things like toe bones are even harder to try and scale up reliably, so I haven't attempted it (also I really would want to see the things first hand before I tried it).

6) So in conclusion, between the specimens that are well enough known to estimate reliably, Tyrannosaurus and Giganotosaurus are about the same length, and T. rex was probably a bit heavier. The big jawed Giganotosaurus appears to be from a larger animal, but the nature of fragmentary specimens being what it is you simply aren't going to get to know which species was "truly the biggest". 

Sorry, the data just doesn't allow this sort of thing to be done conclusively at this point in time, no matter how much we wish it were otherwise.

 

Ornithomimus had wings...as an adult

Just a quick note, because today we got one of the cooler new papers on dinosaurs to have been published in quite a while, describing not one but three specimens of Ornithomimus with feathers.

And not only are there three specimens, but they are of different ages, and it turns out the feathers change as Ornithomimus grows up. In particular, the adults seem to have large wings with branching feathers on them, while the juveniles are covered only with the dinofuzz that we have become familiar with in the Chinese dinosaurs we have come to know and love.

This also pulls protowings further down the family tree - prior to this we only had definite wings in those wacky oviraptorids, deinonychosaurs (the various "raptor" dinosaurs), and those critters on the main bird line.

So for those of you who illustrate the fleet-footed ornithomimids, you may need to alter some of the images. It also brings up some interesting questions regarding what the feather condition is in alverasaurs (which may have been ant-eaters) and the bizarre therizinosaurs. Specimens of the basal therizinosaur Beipiaosaurus have been found covered in dinofuzz and non-branching plumes, but not with true branching feathers, so it was assumed that the origin of wing-like structures must have happened closer to birds. Now it appears that was wrong, and we will have to try and figure out whether therizinosaurs lost them at some point during their evolution, or if perhaps the Beipiaosaurus specimen might have been too young to have developed them.

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There will also be questions about what those feathers were doing in such animals, which clearly did not fly or live in trees (and equally clearly did not evolve from flying or tree-dwelling ancestors); alas that will have to be another post. In the mean time, there are a couple other fun implications to consider from this paper:

1) The Ornithomimus specimens are from fluvial deposits; for those non-geologists out there all you need to know is that most dinosaur deposits around the world are fluvial, so this discover means we will have a lot more museums taking a closer look at their specimens, rather than assuming that feathers can't be preserve outside of a few special depositional settings. In other words, there are going to be a lot more discoveries in the coming years now that more people know what to look for.

2) Along those lines, not all of the feathered dinosaurs are from China anymore. Having been to China and seen many of the specimens personally this never was a big deal to me, but for the couple of stragglers that simply didn't want to believe in feathered dinosaurs, this should end any sort of conspiracy theory.

3) Looking at the already-decided debate about whether birds are dinosaurs, I can't really say that this is the final nail in the coffin - realistically all of the nails were pounded into that coffin years ago. But this discovery makes sure there is a large concrete memorial placed on top of the coffin preventing it from ever being dug up again, and for those of you who lived through the original birds are dinosaurs wars that has to be comforting.

If you have any thoughts or questions be sure to leave them below. And for the paleoartists out there, go forth and illustrated winged adult ornithomimids. Here is a skeletal to get you started:

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Zelenitsky, D., Therrien, F., Erickson, G., DeBuhr, C., Kobayashi, Y., Eberth, D., Hadfield, F. 2012. Feathered non-avian dinosaurs from North American provide insight into wing origins. Science. 338, 510-514