Plioplatecarpus Necromancy: Reconstructing MOR 1062

People familiar with news in paleontology have no doubt seen that the Cretaceous Crossroads exhibit at the Museum of the Rockies recently opened in Bozeman, Montana. Like all major exhibit renovations, this project actually began years before. We at TPI were honored to be invited to work on many of the specimens now on exhibit, including many in the marine section showcasing the fauna of the Campanian-aged Bearpaw Shale. Thankfully, the staff at the Museum of the Rockies have given us permission to share part of the very involved process on how we accomplished this. 

Mosasaurus paddle in the Weskan Shale, similar to the Bearpaw Shale

The specimen I'm most proud of so far is our reconstruction of the small mosasaur MOR 1062. This little specimen is the holotype of Plioplatecarpus peckensis, and as such the very delicate original fossils are best kept securely in collections, disarticulated so researchers can study them. Some museum visitors from time to time seem disappointed that a reconstruction is on display, however what we accomplished made for the absolute best display of this rare and fragile beast.

Disarticulated skull elements of the original specimen

In late summer 2023 we went to MOR to start work on this project. A lot of it was carefully packing some other specimens for safe transport so we could mount original bones, but we also got to scan all the original elements of MOR 1062. Once we found out what was expected of us for the final product, we were a bit nervous. Raising the dead takes a lot of work, in this case nearly 2 years for the project.

Subscale skull prints for reference and outreach

You see, MOR 1062 is a beautiful specimen, however it was a touch on the incomplete side, especially beyond the skull. We would have to reconstruct the lower jaws, most of the ribs, all the paddles, and all the vertebrae from the dorsals on back to the tip of the tail. Hundreds of bones! Where do we even begin?

Early draft of the skull reconstruction, with restored elements colored in puce

The first section we restored was the skull, since the upper portion was almost complete, though most of the individual parts were separated from each other. Mosasaur researchers love their quadrate bones, and their positioning has long been a great conversation starter amongst experts. We were able to print out copies of the back corner of the skull and amazingly, the quadrate clicked into place! Don't try this by bashing the real bones together, but on 3d. This process took a long time, but we may have identified some small skull bones for this animal that initial researchers may have overlooked. We also took the most undistorted quadrate and mirrored it for better symmetry.

Final digital model of the fully reconstructed MOR 1062 skull

The jaws, and a few other skull bones, were "borrowed" from another MOR specimen and digitally modified to make them more svelte and to take out distortion. The material also needed to be resized to fit the teeny skull, and anonymized by removing any pathologies. Originally we used Platecarpus lower jaws as a stand-in, but they were fairly different in shape even though the two genera are pretty closely related. 

3D Director Evan Sonnenberg posing with the complete skeletal print

For the body, we really had to comb the literature and ask other researchers for basic info. We had hard questions like "How many vertebrae are in a Plioplatecarpus tail?" and "What do Plioplatecarpus rear limbs look like?". We were able to use our extensive digital library of our own mosasaur specimens to fill in the blanks as best we could, and finished with a complete skeleton based on real material including the costal (chest) basket. Well over 200 bones needed to be reconstructed for this and the process took many weeks.

Digitally posed 3D model

Next was the pose. Luckily we could do this all in the computer as well, coming up with a model for our assemblers to match. The specified steep diving pose was both fun to look at, and also absolutely required to help the smaller Plioplatecarpus fit in the space along with the larger Mosasaurus specimen MOR 006.

Mounted specimen in its display area while exhibit was under construction

Mounted skull provided for the Dinosaurs and MOR! event in March 2025

Our 3D Director Evan Sonnenberg was invited to talk at the 2025 Dinosaurs and MOR! event about the process and got to unveil the finished reconstruction on stage, which made a huge impression. We here at TPI would like to thank the entire crew at MOR that helped us access the specimens for this project, suggested researchers to work with, invited us to give talks, facilitated the installation of the finished specimens and allowed us to talk little about our involvement.

Walhalla's Sea Snake: Welcome Jormungandr!

Believe it or not, I don't spend all of my time in the field (though it still does tend to be A LOT). In the winter and spring I have time to work on some fossils we find during the year, as well as work on projects for other museums. This past spring, Dr. Clint Boyd approached us about restoring a brand new mosasaur that he and a crew were describing from northeastern North Dakota. He called the critter "Eustace", nicknamed after the BEST character from the Cartoon Network classic "Courage the Cowardly Dog".

Eustace is famous for various disagreements

The specimen was found in the Pembina member of the Pierre Shale and an underlying bentonite was dated to 80 million years old. This is pretty similar in age to our "Walker" Mosasaurus specimen that we excavated from Western Kansas in 2015. I suspected we were in for a very fun project, and something that we at TPI are very capable of doing well.

Walker's reconstructed skeleton

The first step was getting the scan files of the specimen sent over and opened up in the computer. The specimen was fairly complete but missing a few bones. Evan Sonnenberg and I teamed up to reassemble the parts, and remove some of the distortion to make the individual elements fit back together like before they were crushed by 80 million years of rock and geologic processes. Some elements were completed using mirror images of bones from the opposite side of the skull in order to keep Eustace as Eustace as possible. 

Eustace's skull (right) and after restoration (left)

Once that part was completed, we used mosasaur specimens from our digital bone bank to come up with plausible shapes for the bones that were completely missing. When working on the parietal/braincase, lead author Amelia Zietlow kept urging us to make it more Clidastes-ey in overall appearance. And indeed, the paper that came out today does make a case for the new mosasaur being very closely related to Clidastes. Amelia and crew decided to name the specimen Jormungander walhallensis, which is a pretty clever name. The species name indicated it came from near Walhalla, ND, while the genus name plays off of the Norse mythology of the place name, with the name shared with the legendary snake that ends the world in the sagas. 

Once all the parts were there, we printed out two copies of the skull at full size so that they could go on display in museums in North Dakota. While not a huge mosasaur like the Bunker Tylosaurus, the skulls still had to be printed in pieces that were later assembled.

Parts for the top of the skull

Top of skull assembled

Easy enough! Lastly the specimens needed to be painted mounted. There's an external steel armature under the skull and each lower jaw on the copies so that the parts can be removed for closer inspection. One Easter egg that we included in the mount was that each base is a silhouette of Eustace's skull as seen from above. BTW the mini skulls were sent to the authors so they could evaluate it while finishing the manuscript.

The two reproductions were sent to North Dakota this June. One is on display at the Walhalla Library, which is nice having it on display so close to where the original specimen was discovered. The second is due to go on display at the Pembina State Museum in the near future.

Protosphyraena: Like a Swordfish Made Babies With a Chainsaw

We're back from SVP 2017 in Calgary, which was an awesome opportunity to debut our prototype Protosphyraena (Proto Proto) skeletal reconstruction. I've been involved with this project for 13 years now, very heavily for the past 4 with my various research projects with Drs. Jeff Liston, Kenshu Shimada, Bruce Schumacher and Matt Friedman. We've published a bunch of papers and talks recently, and there's even more on deck. If you're in Tahiti next week, stop by and hear my talk!

Image Copyright Mike Everhart

Loomis' reconstruction attempt

Protosphyraena was a tough nut to crack. The first bits were discovered in the late 1700s in the English chalk and first figured by Gideon Mantell in 1822. It got its name later in the mid 19th Century by Joseph Leidy meaning "early barracuda" due to the flat knife blade shaped teeth. Unfortunately this is what happens when you only have sparse material to work with. Protosphyraena is known now to have a basically worldwide distribution however since the animal has replaced its skeletal bone with cartilage wherever possible, more than isolated bits are extremely difficult to come by. In the Bone Wars of the late 1800s, Cope and Marsh's teams discovered many partial specimens in the Niobrara Chalk of Western Kansas, consisting mostly of isolated pectoral fins and skull bits.

Pectoral of P. perniciosa showing saw-tooth edge

The skull was amazing, with a long rostrum and forward-directed massive protruding teeth. The fins showed some variation, however the ones attributed to Protosphyraena perniciosa reached nearly a meter in length ad were adorned with saw-like serrated front edges. A tail fin was discovered near the turn of the last century and then one the first reconstructions was attempted by Loomis.

Cast and original parts at beginning, apple for scale

Not too shabby based on what they knew. Since the body had such little bone, it was highly unlikely that one would be found, yet the Niobrara as usual was full of surprises. In 2003 Mike Triebold found a partial Protosphyraena skull eroding out of the rocks in western Kansas. The specimen was already missing its rostrum, but a bit of pectoral fin was also visible. He continued excavation and noticed articulated evenly spaced spines, and followed them. They were ribs, hemals and neurals, ans they led to an articulated tail. This was the first "complete" Protosphyraena discovered.

Dig site pic, the specimen is already uncovered and pedestalled

This specimen ended up becoming the "Rosetta Stone" for our reconstruction attempt. Though it was a small example, it gave us tons of information about the body proportions. it kept on giving though, showing the streamer-like pelvic fins and large lobe-shaped "go faster" caudal peduncles.

The "go faster" caudal peduncles

We prepared out several specimens of large Protosphyraena in order to have a decent starting point for the reconstruction. One good skull specimen was partially disarticulated, we scanned the gill basket of a second smaller one and reproduced it out at the proper size on our 3D printing rigs. Our pectoral fin donor specimen was famously covered here as the victim of a poaching attempt in 2011. The original bones were molded and we made multiple copies of the parts so we could cut them up into individual elements. They were later remolded with most of the distortion taken out.

The kid seems bored

Jaws attached

Complete skull exterior

After that, the process was pretty easy! We decided to ignore how bizarre the critter was and just accept that's how these parts fit together, seeing where the reconstruction took us. It tuned out to be stranger than we ever imagined, and a lot bigger too, measuring over 2 meters in length (and flipperspan). We showed it off in Canada and it seemed to be a big hit! Enjoy the photos of the finished mount below.

I'm useful as a scalebar sometimes

Down the hatch!

Front view

Reconstructing Chelosphargis: What to do with a pile of bones

We spend a lot of time in Kansas hunting for specimens in the Niobrara chalk. A whole lot of time. Luckily the soft chalk erodes pretty quickly so we also find a whole lot of stuff. Occasionally though, other people also get lucky and we'll happily take the specimen off their hands. In early 2015 this exact scenario played out. You may have seen the result at our display booth at SVP this year in Salt Lake City, overshadowed by our exciting mount of our Daspletosaurus "Pete III"

Curator shadow selfie while digging in Kansas recently

A poorly collected turtle specimen from the chalk was being shown around looking for a buyer, While the collection techniques caused some damage to the fossil, it was plain to see a fairly complete tiny Protostegid was encased in the slabs of yellow rock.

So, this is how we got it. Clearly not how we would collect a specimen.

Most importantly, almost all of the skull was there, which is really nice. We immediately acquired the specimen and prepared the parts. Quickly it became evident we had a older subadult specimen of the relatively rare taxon Chelosphargis advena, an 84 million year old relative of the much larger Protostega and Archelon.

The parts after prep

Skull partway through prep

As you can see, most of the animal was there, in fact it's one of the most complete Chelosphargis specimens ever discovered. But what do you do with a pile of bones once they're all prepared? We're one of the few places with the knowledge, experience and capability to do a complete cast restoration without damaging the original bones. The first step was to mold everything as-is, so we can have parts (sometimes even multiples) to work with.

Cast skull copies getting cut and shaped to take out distortion

Distortion is taken out of the plastic and missing parts are either fabricated from similar ones from this animal, scanned in and resized from other specimens, or in rare cases done the old way with sculpting from reference material.

Carapace getting parts added and completed

The restored parts are then molded again in units so that we can make our final copy and offer it to museums and the general public as a highly detailed cast skeletal mount, perfect for display anywhere. The entire project only takes a few weeks, but the result is pretty phenomenal!

Final product!

Avaceratops layout

If you've been following the progress of our Avaceratops (or something like it) project, you may have noticed a lull in updates, especially after the completion of the reconstruction of the skull about a year ago. This is about to change.

Skull elements present (missing the predentary) Modified image courtesy Scott Hartman

This summer we finished preparation of all the material we recovered from the site, all 170 or so numbered bones plus a good amount of unnumbered things that were discovered deep within the larger jackets during lab work. 

3d model of the skull made using photogrammetry

We had no idea how complete this animal actually was. For the better part of a year the bones were in drawers and on shelves in no particular order, so it never really seemed that impressive.

Bryan and Jacob doing science

Once we laid it out however, we were shocked. This thing really does look like an animal! It takes up quite a bit of space in the "run over by a bus" pose right now, but when assembled, the specimen will be on the order of 13 feet (4m) long, and approximately 4 feet (1.2m) tall at the hips. A cute little juvenile!

Curator for scale

All of the missing bones will either be sculpted from scratch (last option) scanned from the opposite side and printed in mirror image, or be scanned from other ceratopsian specimens and be manipulated in the computer to fit before printing.

Obligatory Ava butt picture.

Platecarpus restoration complete! All hail Cap'n Chuck!

After 8 long years of work, our Platecarpus tympaniticus specimen RMDRC 06-009 "Cap'n Chuck" is finally finished! These last few weeks of the project had been dedicated to finishing the details of the armature as well as packing it for its trip to its new museum forever home. It seems like just yesterday when I was lifted in a freezing drizzle in a Bobcat excavator bucket one October day to investigate a lonely vertebra poking out of the side of a gully wall. Poking around revealed what looked like the rear of a skull, and we decided to come back the following spring to finish the job.

Working on turning a vertical surface into a flat surface

By the time we completed the excavation, we could walk down the debris pile to the gully bottom. We took out multiple jackets since the bone density was so high, working on them in the lab was much safer for the specimen.

Main body and skull block in the Show Prep stage

Once "show prepped" (preparing the jackets to show what is inside of them) we disassembled them and placed the bones in drawers in the Clean Room for safe keeping. There it stayed for years until a customer was found.

Coming together. The white bleached bone 4th from the left is the first bone found

Earlier this year we started restoring the bones for mounting. While we had the bones handy, Cap'n Chuck was molded so copies can be sent to other museums in the future. The mosasaur was incredibly undistorted, the ribs were even round in cross section, unlike the typical Kansas condition of being squished pancake flat.

Dillon (left) vs. Cap'n Chuck (right)

Snakey!

The final result is pretty spectacular. The undistorted ribs helped us get a very accurately shaped torso, with cartilage and even an interclavicle. The skull is beefy and bulldog-like, much different than the lower chalk specimens of Plesioplatecarpus planifrons.

Showing off the pterygoid teeth

Paddle and chest detail

Vertebrae are much larger and more robust than the lower chalk specimens. Surprisingly, the finished mosasaur was a bit shorter in length than we had anticipated, coming in at just over 17 feet (5m) long.

Skull detail

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.