Redesigning a Tyrant: Meet the NEW Tyrannosaurus rex


Note: I know I promised to break down the more complex science behind the T. rex infographic in this post, but as I started putting it all down it became clear it was not going to all fit in this post alongside everything else. I'll be creating an entire post unto it's own at some point on this topic. Now I know what Darren Naish feels like when he mentions having this problem at Tetzoo! - Tom Parker, Saurian Research Lead & World Designer. Redesigning a Tyrant I’d like begin by saying this is all RJ’s fault. If it weren’t for his constant efforts to get us to revisit our rex design we wouldn’t be here today showing off this fantastic new model. While we were very fond of the previous rex concept and it proved to be an effective design for an ambush predator, there were a number of issues with the model that encouraged us to listen to RJ’s incessant whining.

Cryengine rig: The previous rex design was so old it was still rigged to work in Cryengine, which we stopped using all the way back in 2013. Although the model worked in Unity, the steps necessary to get it working initially in Cryengine severely limited our animator Bryan’s ability to set up ragdolls and other basic functions. We desperately needed a new rig.

More Data: In the more than 2 years since the first rex was revealed, we’ve come across new data that improved our understanding of Tyrannosaurus anatomy (more on this a bit later). We planned on correcting and updating these discrepancies, but once we started running into problems with the Cryengine rig we realized that an entire new model was probably in order. Our own pet researcher, Tom, has also been doing a lot of his own work on the structure and distribution of dinosaur integument (skin coverings) which required some changes to be made to the layout on our rex. The simplistic version of this can be seen on our infographic, and a more detailed blogpost on this subect will eventually follow.

Improved Skills: Back in 2013 Jake was not actually as good as we thought he was. He is a lot better now after rigorous training and daily beatings, as the Acheroraptor and the rex show. Bryan also picked up several new techniques that he was interested in implementing that were stymied by, you guessed it, the Cryengine rig.

RJ & Chris: RJ Palmer and Chris Masna both joined the team after the design process of the prior rex concept. Now that we were faced with the prospect of an entirely new sculpt and rig, it was only natural to incorporate their input and suggestions to improve the entire design.

And you can see the result of their collaboration below

Infographic describing the science behind the appearance of our Tyrannosaurus rex.


Tyrannosaur footprints

[/one_fourth] Other updates

Feet: T. rex now has sexy new feet based on newly discovered fossil trackways of a closely related tyrannosaurid from Canada. Among the changes from the old model are a revised arrangement for tarsal scutes and tapering toes that have significantly more padding to them. The innermost digit also possesses a slightly enlarged claw, hinting that incipient “killing claws” were likely ancestral to all of Coelurosauria (Fowler et al. 2011). Additionally, the outermost toe is now more noticeably splayed from the middle and inner toe, further hinting at a partially raptorial ancestral condition.

Girth: While the old rex was plenty robust, as Scott Hartman illustrates below, Tyrannosaurus rex is really built like a barrel. As this graphic was released well over a year after we had completed the old model, we didn’t have a chance to incorporate it into the design the first time around. A comparison will also find the new sculpt is significantly beefier than the old one, as Jake has taken better account of body fat and other soft tissues.

Reference Specimen: As some of you have noticed and as we mentioned in the stream, our new rex is based off of the "Stan" specimen (BHI 3033), rather than the "Sue" specimen (FMNH PR2081) as the original was. We’ve made this shift for a couple reasons. The old rex is based off of a now inaccurate skeletal from Scott Hartman, Sue is actually more robust and proportionately short legged than our original model was. We also selected Stan for his smaller size. Stan is a relatively small, young adult tyrannosaur, so basing our model on it allows us ‘room to grow’ into a large adult. One of the primary reasons we’ve based the new rex on Stan though is his stratigraphic age; Stan was found within the upper third of the Hell Creek Formation, about 16m below the K/Pg boundary (Johnson & Hartman volume 2001). Sue is from the lower portion of the Hell Creek Formation, making it potentially up to a million years older than Stan and Saurian’s setting. Other T. rex specimens from the same position in the formation as Stan are MOR 555 (The Wankel or ‘Devil’ rex) MOR 980 (Peck’s rex) and potentially AMNH 5027.  All of these specimens appear to be relatively gracile compared to other specimens of Tyrannosaurus, which is frequently used to suggest that they are male. However, once again GET AWAY TRIKE has done us a huge favor by noting that most of the robust individuals of T. rex that we have stratigraphic data for appear to be from the lower portion of the Hell Creek Formation. This suggests that instead of different sexes, the robust and gracile ‘morphs’ of Tyrannosaurus might instead represent change in form over the course of Hell Creek time, similar to the transition from Triceratops horridus to Triceratops prorsus.


We've also started utilizing Root Motion to blend together the model's animations, and we're very excited by our early results.

After several months of hard work to bring all of this research and artistic collaboration together into one model, we're extremely happy with the result, and its gratifying to see all the positive comments our followers, other artists and even paleontologists have shared with us. Thank you for supporting us, and we look forward to showing you more updates like this in the near future!

References - Fowler et al. 2011, The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds, PLOS One. - Johnson 2002, Megaflora of the Hell Creek and lower Fort Union Formations in the western Dakotas: Vegetational response to climate change, the Cretaceous-Tertiary boundary event, and rapid marine transgression, Geological Society of America Special Paper 361, pp. 341