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.

Digging more holes in Kansas

It's been quite a while since the last update, but that's because of all the field work we've been doing in western Kansas. Hell, I feel like I've been digging deeper holes than Kansas' Governor. Ha! Biting political humor.

In any case, Jacob just released a video that has a few awesome action shots of me staring at the ground, and a really ugly (well, even uglier than usual) Xiphactinus that I found before we started working on it. Check it out and don't forget to subscribe to his youtube channel or the Dinosaur Nerds website so you can see all kinds of boring thing like me complaining about mosasaurs.

No love for Ichthyodectes?

It seems like nearly every year a new book, film, or television program comes out featuring the long-dead seaway that covered most of the central part of North America back in the late Cretaceous. Invariably they have cameos featuring Xiphactinus, Cretoxyrhina, Protosphyraena, and even the "bait fish" Gillicus and Enchodus. They have mosasaurs, pterosaurs and even sea turtles. If you didn't follow the science closely, you'd understandably figure that's about all that lived in that shallow sea.

Our cast specimen restored in all its 3d glory

Truth be told, there were probably a few hundred types of fish in that seaway. Dr. Kenshu Shimada made a decent attempt to catalog all of them a few years ago, but like all good science on the Niobrara, it was getting out of date almost as soon as it was published. It's really amazing that 120 years after collecting work began in Western Kansas, new critters are still being found. I'm not going to go into details on them (I'll save them for other blog posts) and instead focus on this fish that is criminally underrepresented in the literature and online.

RMDRC 11-018, a massive 9 foot Ichthyodectes

If it's Wikipedia entry were any indication of its importance, what does the text containing a whopping total of 89 words tell you? That's right, 89 whole words, some of which are even talking about other related fish. Lame.

Some of the teeth of RMDRC 11-018. Yikes

Ichthyodectes, a fish with moderately terrifying teeth and with a body length approaching 9 feet, it's not cheered on much. Sure it's pretty common in the Niobrara, but it's also basically a pocket Xiphactinus (see, using the Wikipedia trick of talking about it's cooler cousin to gin up some interest). An average scouting season for us will find 5 or so specimens identified through cranial material. Probably more, but postcranially all ichthyodectids of about the same size pretty much look identical.

RMDRC 14-027, excavated with a film crew, watch for it soon on TV!

Perhaps a big reason as to why Ichthyodectes gets so little love is that there are so few specimens on display in museums, even fewer ones that look, um, not silly. Perhaps we need more museums to decide that decent specimens of lesser known fossil fish of the Niobrara are just as important for display as mosasaurs or sharks or Xiphactinus. Maybe I'm just asking for too much. In any case, I've pretty much doubled the amount of useful Ichthyodectes pics on the interwebs, so I'll count it as a win.

Actual Mosasaurus from Kansas

Mosasaurs in Kansas, no big deal, there are thousands of specimens known. But what about the actual genus "Mosasaurus"? As recently as 1967, Dale Russell's excellent mosasaur book claimed "Mosasaurus ivoensis" was present in the Niobrara. Since then, Johan Lindgren has moved the holotype of that species (from Sweden) into Tylosaurus. The lone Kansas specimen originally described by Williston in 1902 looks to be attributable (to my eye) to existing known Niobrara mosasaurs, most likely Platecarpus and Clidastes.With the loss of the one possible chalk specimen we're left with a sort of sad thought: Mosasaurus didn't exist in Kansas.

Until now.

Excavating the skull parts

This spring a TPI field crew accompanied by famed Kansas Cretaceous expert Mike Everhart came out to Wallace County in far western Kansas at the request of a private landowner. We were investigating a report of a mosasaur eroding out of the Weskan member of the Pierre Shale, immediately above the much better known Sharon Springs member. Hardly any people work on collecting fossils out of the Weskan, so we were excited for this opportunity in virtually unexplored country. The critter, RMDRC 14-015, got the nickname "Wally" after Wallace County, and was brought back to the lab this spring.

Nice flipper

After recovery and prep it was obvious we were dealing with a pretty darn big mosasaur with a skull about 4 feet long, but what could it be? The only reported specimens this size out of the Pierre in Kansas could be Tylosaurus or Globidens. Prognathodon crassartus from "Eagle Tail, Kansas (now known as Sharon Springs) turned out to just be Plioplatecarpus. the premaxilla lacked a substantial rostrum so that excludes Tylosaurus, though its slight nub of one also excludes Prognathodon (known from other Pierre deposits). The teeth are all sharp and pointy, so not Globidens (yes they are pointy in juvenile Globidens, but with a 4 foot long head, it's silly to consider this critter a juvenile). In the end, with the characters we saw, there was only one logical conclusion.

Bite mark on frontal

Yes Virginia, there really is Mosasaurus in Kansas.

Bulky snout

In fact now there are two: We started recovery of another even larger and more massive specimen from the same ranch at the end of October, RMDRC 14-050. More on that this spring when we return to finish the site. The coolest thing is how the specimens display both advanced and primitive features usually assigned to one or another species of Mosasaurus, but not all in one. It's probably a brand new species, which is really exciting for us.

We are currently restoring and molding the complete skull of RMDRC 14-015 for debut at the Tucson Gem and Mineral show this January, in fact the palate it being installed as I type. The rest of the specimen may take a bit longer to restore, but the world always needs more 30 foot long water lizards. And you can quote me on that.

Newest digsite, mainly concretion

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

Beefy Platecarpus Restoration Update!

For the past few weeks, TPI field crews have been scouring the outcrops of Western Kansas and finding some spectacular specimens. More on those in a future blog update.

Since the field crew was gone, the lab crew is much less distracted and has made great progress in assembling the Cap'n Chuck specimen of Platecarpus tympaniticus. Skull reconstruction is now complete and painting of the small restored areas is all that;s left. total length ended up being 52cm, but the width gives it more of a bulldog appearance than the lower chalk Plesioplatecarpus planifrons. I'm still trying to get used to all these new names since the reclassification of plioplatecarpines a few years back.

Top view

The only bones I was completely missing were both squamosals, but they were pretty simple to fabricate.

If you look carefully, we even included the mounted epipterygoids

The skeleton has had individual clips fabricated to hold each bone securely in place. Those subassemblies are now being fastened to the armature. The specimen is intended to be hung at its future museum home, however building it on cables in the lab is too unsteady. The posts supporting the superstructure will later be removed before shipment. The light colored vertebra fourth from the left is the first part of the mosasaur I discovered coming out of the outcrop.

Ribs beginning to be fit, though all still need adjustment

Individual bones are assembled into segments so that it can be quickly and precisely set up in a new facility. All limbs are removable, as are the ribs and skull. The vertebral column breaks down into segments. With any luck though, the steel armature will be nearly invisible on the final mount.

Front paddles nearly assembled.

Cap'n Chuck Rises: A Teaser

Like many places, progress on various projects here ebbs and flows. Sadly, the Pete III Daspletosaurus restoration project has been temporarily put on hold so we can address more pressing matters. In this case, it's Cap'n Chuck (RMDRC 06-009), a fairly complete and extremely well preserved Platecarpus tympaniticus specimen that I discovered one cold October day in 2006. A recap of the early part of the project can be found by clicking here. Once prepared the specimen sat in drawers in my office for years.

Squalicorax bites on the top of the skull

That's a nice set of ribs

Recently the powers that be have decided that we should restore and mold the skeleton to replace the smaller Platecarpus planifrons skeleton in our cast catalog. Comparing it to the lower chalk mosasaur, Cap'n Chuck has a nearly identical skull length, more gracile lower jaws and wider top of the skull, however its postcranial skeleton is radically different in proportions. Humerei and vertebrae are nearly twice as big. The ribs are surprisingly uncrushed, preserving their original round cross section as well as curvature. In fact they are so well preserved we can even with some degree of certainty determine which ones belong on the left or right side (nearly imossible to do on typically crushed ribs).

Lower jaws, slender and displaying symmetrical tooth replacement

Nearly complete axis showing beefiness

The differences really are amazing. A few years back, Takuya Konishi split Platecarpus planifrons into its own genus: Plesioplatecarpus. I was very skeptical of this split for a long while, but now after comparing the low chalk mosasaur against its upper chalk relative, I'm really beginning to see his point.

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.

Infected tails do it better

Sometimes you work on a fossil and just think "oooh, that had to hurt". This tail from a pretty large Clidastes from the upper Niobrara chalk is fairly boring when viewed from afar. Up close though something just doesn't look right.

Yep, pretty boring

Of the 45 bones, 23 are pathological, with 17 of them fused at the centrum in 5 separate masses. All of these bones lack transverse processes, so they come from the lower lobe of Clidastes' bifurcated tail fin: a bit of dangling flesh that might make for a tasty morsel for a predator.

I think this mass used to be 8 separate vertebrae, based on the number of chevrons

The bones, though mostly healed, show bone growth consistent with a long infection. As the tail was the primary means of locomotion/propulsion for mosasaurs, this injury must have been very painful for a very long time for this mosasaur.

3 verts become one

Fused verts, and centra with vertical scars

Soft tissue preservation in a Platecarpus

This past week we were able to do a bit more work on a specimen that we collected last spring with a student group from the University of Tennessee-Martin. This small mosasaur, a Platecarpus planifrons RMDRC 11-001,  was just about the only recoverable mosasaur material seen on that trip. This specimen was discovered by a UT-Martin student, and the discovery, excavation and recovery process was recorded by a UT-Martin journalism student group.

How many people can you fit on one digsite?

The specimen was brought to the lab and awaited the UT-Martin student group to come to Colorado to prepare it. That chance came this week. The skull was weathering out first, and the roots of nearby plants had started growing around the bone making preparation a bit tricky. The students and film crew covered the preparation of the torso and neck, which was in much better condition. I was left to work out the skull.

Partially prepared torso, neck and head

We were paying special attention for anything that would tell a story about the animal. First we discovered gouges from shark bites on the lower jaw, then a shed sharks tooth at the left articular. While slowly preparing around the quadrate, we located the extracollumnellar cartilage, a semi rigid plate that often gets mistaken for a calcified tympanum. I waas shocked that this was still present with so much root infiltration. later while preparing between the pterygoids, small remnants of the tracheal rings were also discovered. I expected them there if present since they tend to get blown forward through the mouth after death, looking like a linguine dinner after a hard night of drinking. Unfortunately, no skin was present on this specimen, but as always, we'll be keeping an eye out

Can you spot the tracheal rings?

Tracheal rings in another specimen, this time a Clidastes

Finished! Platecarpus skull pictures

I dress well

Its pretty side

Its other pretty side

Not much of an update, but I need to close out this project I've been blogging about. The world's largest Platecarpus planifrons skull is done and in the crate, ready to ship to Tucson. Hopefully I will never see it again!

Shark bites on the face