Digging a tyrannobutt

We're back from Montana waiting for the temperatures and fire danger to die down for a bit. Earlier this month though we were battling the gnats working on excavating a dinosaur I found late last summer.

Can you spot the site?

The site is pretty typical for how I find them: about halfway up a 30 foot cliff with a menacing hoodoo overhanging the specimen. I found this site about 2 days before we broke camp last year so I was only able to do the smallest of evaluation digs on it.

Bones on either side of an erosional notch: usually a good sign

 Using air tools I was able to notch out a few of the bones. These were clearly large theropod bones, one looked like a caudal vertebra and I couldn't tell what the one shooting straight into the cliff was. Big theropod in the Judith River formation means one thing: Tyrannosaur! I knew I'd be coming back for this site in 2017.

Duckbills. It had to be duckbills

Additionally at this site was a big wad of predepositionally broken ornithischian (most likely duckbill) bones under the tyrannosaur material. This gave the impression of a stream or oxbow lake bottom assemblage, but sometimes you find good skeletons mixed in with all this material. Unfortunately with fall closing in, I had to abandon the site till 2017.

Storms are no fun in vehicles that lack roofs and windshields

This year however we came out with our big jackhammer and managed to notch out a decent sized evaluation pit. I wanted to get a better feeling for what was present before I suggested getting a bulldozer out there to knock down the whole cliff.

The isolated tyrannobutt

Turns out, it appears it was just an isolated tyrannosaur sacrum with one dorsal vertebra still attached. Not pretty now, but once I prepare it we will see better the shape of the specimen. I'm thinking Albertosaurus, but it's hard to say from this element.

Closeup of the spines. Bonus duckbill chevron at top left

It's a bit of a bummer that there wasn't more of this skeleton. It was going in towards the head but it was just not meant to be. I'm happy to find this now before we invested time and resources removing 15 feet of really tough sandstone from the area though. Guess I'll just have to spend the rest of my summer looking for more dinosaurs. It's a tough job but somebody's got to do it!

Daspletosaurus reconstruction progressing: Pete III

You know, I think I'm just going to share some pictures as an update to my last blog post. We'll keep the reading part short and sweet. Restoration is coming along well. The skull is up next, and in the meantime we have the leg finished and the arms almost there. Lots more to come over the next few months. It's always good to have new tyrannosaur stuff to play with.

Pete III's scaps and arms

The scapulae were remarkably well preserved in 3D

Left leg before paint

After paint, left leg from the rear

Side view, the leg is HUGE!

Pete III makes progress: Molding a Daspletosaurus

It's been a long time, not only since I updated the blog, but since we've had any news about our big Daspletosaurus specimen that we dug up in 2006. Well, that's changing now.

Original and prototyped bones

This is basically an update on a post from a few months back where I covered the scanning and printing process if the leg. To get the project moving along we picked some of the low hanging fruit: finishing the left leg! Since this leg was almost complete (missing just one phalanx and strangely, metatarsal III) the restoration was pretty straightforward, comprising of just crack filling. The digits were molded in gang molds and we produced a mighty fine block of metatarsals II through IV.

Original leg ready to mold

That block as well as the long bones were molded so that they can be loaded onto our spin casting machine, enabling us to make high-fidelity hollow casts (saves a lot of weight) that we later fill with urethane foam for durability.

Cast copy of the left pes ready for assembly.

This leg should be ready for display in about 10 days, so don't forget to come by the museum to check it out.

And now for something slightly different

You all deserve a brief respite from the dead fish and Avaceratops update barrage. What better excuse to talk about our big Daspletosaurus Pete III then? It's about the only dinosaur we have that people tend to ask about anyway. We've had an opportunity to catch up on a few projects lately and are able to spend some time in preparing the final few bones from their field jackets, while also restoring the skull bones to get them ready for 3d laser scanning and printing.

Bryan finishing the neural arch of caudal 2

I'm sure you have heard about the special challenges that preparing Pete III poses. I even did a paper on it, which is posted on my academia.edu page. When done, the bone itself is pretty stable, but it just looks somewhat ugly since it's made up of thousands of small fragments. We've adopted a technique using tinted hydrocal to fill in these small surface gaps to help give the bones a little more strength as well as make them look less pixellated (to borrow a term from a friend).

Left jugal after initial prep

Left jugal beginning restoration

Left jugal after finishing

Pixellated right quadratojugal

Much better with plaster

And in further comparison to the size of Pete III vs. Tyrannosaurus rex, here's a teaser comparing the left ectopterygoids of our Daspletosaurus vs a mounted copy of a rex. Not a whole lot of difference there overall.

Can't wait to get finished with this head...

Field season in full swing

Sorry for the lack of updates lately. We've been in South Dakota and Montana working the Hell Creek and Judith River Formations respectively.

Jacob for scale before we open a Triceratops site

South Dakota had seen its fair share of rain, where we got rained out more in two weeks there than in my entire previous decade of Hell Creek digging combined. We pulled a few Triceratops bones and finished evaluating a few sites before moving on north.

Nanotyrannus teeth collected from a single lag deposit

In Montana, our main focus has been opening the Avaceratops dig again and pulling out more of the animal. Lots of bobcat work The back wall of the quarry is nearing 10 feet tall now. Hopefully we're ending the dig soon so we can explore... Enjoy the photos!

Huge fault in the Hell Creek. Jacob somewhere to the left

It's the greenest I've ever seen in July for Montana in the JRF

I cut the steep part of the bobcat road. It's pretty scary to use. 

Duckbill butt I found a few years ago. Finally excavated this year.

After excavation and pedestaling

Part of the Avaceratops braincase

Ava site a few weeks back, before Bobcat work to push the wall back

Our own "Project Daspletosaurus"

There has been a fair bit of blog hype recently regarding Dave Hone's fundraising project to study cannibalism in tyrannosaurs. BTW if you feel like kicking in a few bucks, you can do so here. In short, they've observed tyrannosaurs in Alberta that seem to have been eaten by other tyrannosaurs. Neat.

Special thanks to Henry Mendoza for helping sort this drawer of teeth

It got me thinking: "Gee this sounds really familiar, where have I seen this before? Oh right, in these drawers right behind my desk!".  TPI fieldcrews recovered an 11m (35 foot) long Daspletosaurus specimen in 2003 from the lower Judith River Formation of Petroleum Co., Montana. This specimen, known as BCT or "Sir William" was originally thought to be a juvenile Tyrannosaurus rex based off of it's surprisingly low dental tooth count (only 13, Daspletosaurus should have 18-ish) and because of a field stratigraphic error (the rock unit was marked as Hell Creek Fm on some older geologic maps).

Small through large shed teeth from the site

The specimen was recovered in a very hard sandstone and much of it was encased in ironstone concretions. Preparation was difficulty but something stood out: The huge number of shed tyrannosaur teeth mixed in with the main specimen. A whopping 52 teeth from various sized tyrannosaurs shed at this site, in addition to several other rooted teeth that are definitely from BCT.

An example of the big teeth from BCT

So what does this mean? Well, it's another data point that goes a way to confirm the hypothesis, plus we can show that it happened in other geographic areas and with possibly different species of Daspletosaurus (I'm confident that BCT is NOT Daspletosaurus torosus). Plus, in the end, tyrannosaur teeth are just neat.

Daspletosaurus prep update: now with arms

Hip block. Yowza.

I know I've spent a lot of my previous blog posts focusing on the Platecarpus skull we were getting ready to send off witht he travelling circus to Tucson. Well, they're out the door and I can swing my attention back to our Daspletosaurus "Pete III".

Need some claws

Preparation  is about 98% finished, with a few straggler parts and the pelvis block to finish up. We've also begun the restoration of some of the bones, partly for increased stability and partly because they're much less ugly now.  Mark Wildman posted on his blog recently a tidbit mentioning Daspletosaurus had the longest forelimbs of any tyrannosaurid. I'm not sure if that's correct, however comparing our measurements with others published for Tyrannosauurs rex, we're a bit longer overall, even though we estimate Pete III to be nearly 10 feet shorter in overall length than "Sue".

The beginning of restoration of the arms

One of the nice things about preparing and restoring these bones (finally) is that we can uncover some new information about Pete III. Based on the size of its femur, we can estimate it was around 20 years old when it died, which is pretty old for Daspletosaurus. I've starting to use "it" when referring to Pete III because one of the next mysteries I hope to solve is whether it was male or female. Stay tuned for updates!

Daspletosaurus prep update

Jacob and I have been hammering away at the remaining small jackets of Pete III. By small I mean things less than the 4 ton main jacket monstrosity that we'll eventually have to confront. This week we've finished the left femur and ilium, along with a slew of gastral elements, vertebrae, and other bits and pieces.

Anterior dorsal of Pete III compared to Stan

The ilium has a strange mass of punky bone on the medial face of the pubic peduncle. We've seen a few instances of old age related pathology on this specimen, it wouldn't surprise me to find more.

Medial surface of left ilium, 42 inches long

Before long, we'll be started on the pathological tail section. Can't wait!

Caudal view of left femur.

Daspletosaurus prep restarts: this time with skull bones

While I was away soaking up pathogens at SVP in Las Vegas last week, paleotech Jacob Jett has been busy preparing some of the jackets from the weathered edge of Pete III's excavation. The bone was in difficult shape to begin with (earning the nickname "The pixelated Tyrannosaur" at SVP) before seeing several hundred Montana freeze-thaw cycles, making this prep work one of our greatest challenges to date. However, results are here! Skull bones so far include both quadrates, a jugal, both quadratojugals, a spenial, pterygoid and possible surangular, with more to come. No toothy bits yet though.

The left quadrate. Actually recognizable!

Dorsal vertebra #1, giving you an idea of the sheer size of Pete III. Transverse process span is 15 inches (38cm)

Surprise! Manual phalanx!

We still have many jackets (including the majority of the big 4-ton monstrosity) to prepare, however we're confident that the majority of the skeleton and perhaps 20-30% of the skull is here. Check back for more updates!