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

Enchodus rears it's head!

Over the past few weeks, Jacob and I were out doing some scouting and excavation in the lower Niobrara chalk in western Kansas. With the recent drought in the area, not much erosion has happened and so specimens were a bit tough to come by. Though we were blessed with instructions to just record fish localities, secure them, and move on, sometimes the fish are just too good to pass up.

Enchodus palatine fang eroding out

One of our long term goals is to expand our 3 dimensional fish reproductions from Kansas. We've completed 4 so far (Xiphactinus, Ichthyodectes, Saurodon, Pachyrhizodus) and we're working on Megalocoelacanthus as our 5th. Enchodus has always been on our wish list (one of the most common fish in the WIS, and those fangs... people love pointy parts), however the large specimens of Enchodus petrosus are very rare, especially anything resembling a complete skeleton and not just isolated palatine bones with fangs.

RMDRC 13-001 fanf after prep

Jacob struck first with a very large Enchodus fang protruding from the grey chalk between MU 7 and 8 He took down the overburden and exposed a sizable disarticulated skull with pectoral fins and vertebrae. We prepared a good portion of it in the lab and have decided that this specimen is where we will mold the majority of the individual elements from.

RMDRC 13-001 digsite

A few days later I was working an outcrop slightly lower (just above MU 6) and was shocked to find an articulated skull weathering out of some seriously soft chalk. I hoped it was attached to the rest of an Enchodus.

RMDRC 13-005 as found

Originally we were going to "Sternberg" the specimen (pouring plaster directly over the exposed bones to stabilize everything in the jacket) assuming that there was more resent at the site. Unfortunately, sometimes all you get is a head. In this case a giant one (lower jaw 25cm long) indicating an overall length of about 1.25m. This will be the basis for our overall reconstruction.

RMDRC 13-005, bottom side prepared

We're hoping for the prototype to be completed and ready for SVP at the end of October. Fingers crossed.

Megalocoelacanthus restoration in progress

As many of you know, here in the lab we have a thing for rare stuff out of the Niobrara chalk. We've found the only articulated skeleton of Protosphyraena, described the giant filter-feeder Bonnerichthys, we make a habit of collecting excellent cephalopod mouthparts like Spinaptychus and Rugaptychus, and even discovered the only open coiled ammonite out of the whole formation. So when it comes to new giant coelacanths out of Kansas, yeah we're on that too!

The second specimen (left) with a cast of the left lower jaw of the first specimen

The first specimen of Megalocoelacanthus from Kansas was prepared by our lab in 2005. It was given the name "mystery fish" since the bones looked nothing like what we usually work with. The bone quality was pretty nice, and comprised a nearly complete skull. It was eventually identified by Dr. Ken Carpenter (at the Denver Museum at the time) as a coelacanth, and the specimen went off to a repository.

Sculpting a body with the Vienna Latimeria specimen  blown up to size

While preparing and molding the specimen, I discovered a second specimen in 2007 much higher in the chalk consisting of a left lower jaw. As far as we know, these are the only two specimens of Megalocoelacanthus ever discovered in 150 years of paleontological prospecting in the entire Niobrara.

Side fiew of the unpainted and almost finished prototype

From past projects, it is obvious that we are the only people crazy enough to do 3d restorations of Kansas fish. We had disarticulated casts of the whole head of this giant coelacanth, so why not attempt a restoration?

No teeth, but it could nearly swallow me whole with that maw

Well, here's our first stab at it. In the future we're going to have to un-flatten the mandibles so they better fit the floor of the mouth. One thing is for sure though: it's still a strange fish even when all put together.

More Mosasaur Fun, Complete With Spectators

Just finished a sort of long-term new project for us. Occasionally we get requests from museums and universities to come out in the field with us and collect specimens. Even more occasionally, we oblige. In 2011 a class from the University of Tennessee - Martin (actually 2 classes, one in geology, one in journalism) came out to our digsites in western Kansas to find and document fossils for a new museum project. TPI fieldcrews supervised and instructed, however we let the students do the finding. They came up with several neat little fossils (several Spinaptychus, a Chelosphargus partial skull, Martinichthys skulls) and lots of partial fish. On the second day, one student hit the jackpot: the tip of the lower jaw of a mosasaur poking out from just under the alluvium. 

Ever feel like you're being watched?

Here, Aaron (the discoverer) works to remove overburden from the specimen. TPI does the same thing, though usually with fewer spectators. He decided to name the mosasaur "Kimberly". I've named specimens worse things I suppose.

Digsite viewed from across the gully, right near MU 5

 The specimen was tentatively identified int he field as Platecarpus planifrons. Though reasonably well articulated, it was missing the front limbs and everything back behind the mid dorsal vertebrae. UTM students preimetered, stabilized and jacketed the specimen. Most importantly they also carried the slab across the badlands to the nearest truck, which was great for me!

Standard TPI field photo pose, before jacketing

Back in the lab, preperation was begun by UTM students under TPI guidance. Mosasaurs are usually pretty straightforward to work with, however this one presented a few challenges. The proximity to the alluvium meant that this specimen encountered some weathering back during the last ice age, and roots made matters worse. The prognosis was grim initially, as the bone and teeth looked to be in pretty rough shape. But careful consolidation and prep resulted in not only stable bone, but the discovery of the preserved remnants of tracheal rings, as well as extracollumnellar (ear) cartilage. At the rear of the left lower jaw, one of the scavenging sharks, Squalicorax falcatus, left its calling card.

Kimberly's skull

Next up the specimen will be delivered to the new museum in Tennessee, where it will go on display later this year. Luckily the whole process was documented by the journalism students, almost from the instant of discovery. If I see the video, I'll post a copy on the blog in the future.

Not a bad little mosasaur.

Stangerochampsa: Weird Hell Creek Croc

Last thanksgiving when I was in Illinois visiting family, I got to take a day to visit the Burpee Museum in Rockford, IL. While there I got to pick up molds and original bones from one of their discoveries from the Hell Creek Formation of eastern Montana. Ernie is a small alligatoroid, apparently related to the much more common Brachychampsa. I never seem to be able to complete any vacation without becoming some sot of fossil transporter, however it gives me a chance to see a lot of new places along the way.

In any case, we've spent the past few months working on the specimen. It was pretty complete as far as Hell Creek crocs go (which isn't saying much, though if you saw the poster on the specimen at SVP last year, you have a pretty good idea) but it needed some parts badly.

Skull bones getting molded

The first thing we did was remold the individual skull bones and any other originals. Using the molds provided by Burpee we poured casts of the postcranial elements as well. In the end we had a nice skull and less than half of a body. How do we improve on that?

Donor gator, tail skilfully removed for shipping

Donor gator of course! Dr. Ray Wilhite from Auburn University was able to get us a 49 inch long frozen Alligator mississippiensis. It was a great day in the lab when the package arrived, not even oozing at all! Jacob and I did a dissection on it to see how things move on recent animals, then stripped most of the muscles and skin off of it before sending it to the dermestid beetle colony for final cleaning. The skin, especially the osteoderms were a lot more difficult to remove than we had originally planned.

Processing through, those jaw muscles give me nightmares

While the beetles were chewing away at the smelliest part of the gator, Jacob restored the missing bits of the casts of the original material. Missing neural spines and transverse processes were sculpted. When we got the modern bones back, they were disassembled and molded. Where possible we incorporated any part of Ernie into the restored bones.

Ernie's coming for you!

I especially like the shadow

Once remolded, assembly was pretty straightforward. The prototype was completed this week and will be headed back to Rockford for display in the upcoming brand new "Homer's Odyssey" exhibit in a very shortly!

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.

The Little Protostega is Restored!

A final follow-up on the project that I had mentioned in the last update. The project is "finished" for now, all molding is complete and the first two prototypes have been assembles and packed.

Cast bones and skull restoration before assembly

We molded hundreds of individual bones for this project. Those cast parts were restored, put into subassemblies, then remolded to produce the final cast. The cast preserves all the pathologic and taphonomic detail, including what appears to be puncture wounds from predation by one of the many mosasaurs in the Niobrara. I blame it on Tylosaurus.

Prototype #2 flying by the green screen

Prototype #1

Prototype #1 with curator for scale

Amazingly, the whole animal now goes together from a trimmed cast to a final project in less than a week. The first specimen was given to the Sternberg Museum at Fort Hays State University to accompany the original specimen now safely in their collections. The second cast will be on display beginning next week at the Tucson gem and mineral show, at the 22nd street show. Come by and check it out!