Restoring the skull of Texas Nessie

It's not just your imagination, we have been EXTREMELY busy in the lab and 3D department working on all sorts of new reconstructions of animals. I'm very proud of this next one, which debuted at the TPI booth during the Society of Vertebrate Paleontology annual meeting in Minneapolis this past fall.

The completed polycotylid skull

This skull belongs to a fantastic specimen of polycotylid plesiosaur excavated in 1991 by Mike Donovan, a collector working in the Eagle Ford Shale of Texas. After Donovan passed away, this specimen was donated to the Heard Museum in McKinney, just outside of Dallas. Shortly thereafter we were contracted to mount the original skeleton for display. You should really check it out, my friend Pamela Riddle made the custom mural that's the background for it and I think it looks spectacular. Several paleontologists are working on the description of this animal, and I hope to see the finished paper out soon.

Photo of the display from www.nbcdfw.com

Fast forward to November 2023: Evan, our 3D Director, drove with me down to Dallas for a few projects. In addition to getting to meet up with Pamela at the Perot Museum prep lab we also were able to visit the Heard in order to work on the skull. Darlene Summerfelt was gracious in accommodating us even though she had a touch of a cold a the time. Taking the specimen off of display was a stressful experience, since the real skull bones were mounted individually around a steel armature and plastic casts filling in the reconstruction. 

Darlene (L) and Evan (C) working on the skull as museum visitors observe

We scanned all of the original material and carefully reassembled the skull onto the mount in just one day. That, it turns out, was the easy part. Once back in Colorado we consulted with plesiosaur experts as well as with our own virtual 3D library of plesiosaur material to digitally reconstruct the skull of the animal. Special thanks to Mike Polcyn for letting me pick his brain.

Evan scanning reconstructed jaw parts in the Heard Museum

As you can see, even when the skull is completed, there was a lot of distortion from being buried under Texas for nearly 90 million years. Luckily we were able to remove this deformation. In the old days, during the 2004/5 reconstruction of the Martinectes (formerly Dolichorhynchops bonneri skull, this was done by making plastic casts and then heating and bending them, with lots of manual sculpting, to get them to resemble what they looked like in life, a difficult and time consuming process. 

Early reconstruction work showing the crushed-down top of skull

Once done with that we were able to print out a copy of the completed skull, which I got the privilege to assemble. Working with these highly detailed prints isn't the easiest thing to do, but I've had some pretty good experience with this reconstructing the BCT Teratophoneus skull, the mosasaur Jormungandr, as well as quite a few secret upcoming projects that you'll have to stay tuned for. 

The assembled print of the top of the skull, with me for scale

This one has made it back to Texas for the Heard Museum to put onto display (the Heard's Darlene Summerfelt for scale in this photo). She says she loves the reconstruction. Now that it's available through the www.trieboldpaleontology.com we hope other museums are just as impressed and order one today!

Darlene Summerfelt with the full size (and mini) skull reconstructions

Fall Xiphactinus Surprise

Let's go to Kansas they said. We'll find some marine reptiles they said. It'll be fun they said. Boy, were they wrong!

October is tarantula migration season

Doing fieldwork in Kansas at the end of October is pretty rare for us, but we lucked out with the weather and spent a few days hitting outcrops we hadn't been on in a few years. It's important for them to go through an erosive "refresh cycle" so that we can find new stuff on the same ground. In just the first day we found the remains of a partial Pteranodon sternbergi and a few cool small fish. Mike and Jacob were working on excavating Pteranodon #6 of the year and I was finishing up jacketing a nice Ichthyodectes ctenodon specimen and had a little time to kill, so I wandered off to the south a little bit to scout for some cool treasures. I had been over the area just a few yeas before, so I was expecting something small.

The chin

Curator at digsite for scale

That's when I accidentally found the biggest fish of my career laying on its left side. I nicknamed it "Nia". She's a Xiphactinus audax over 17 feet long when whole, with pectoral fins each 2 feet long.

There was a serious lack of overburden at first

Luckily overburden wasn't a big problem at first, with an average of about 4 inches (100mm) of chalk over the specimen. Digging in though, the articulated strand of ribs, spines and vertebrae were pointed straight into the outcrop wall.

Expanding the digsite

The Niobrara sea was chock full of predators ready and willing to scavenge a dead animal, and they didn't pay Nia any respect either. We discovered a half dozen shed Squalicorax falcatus teeth in the head area, lost while taking chunks of meat off the carcass. Unfortunately (or mercifully, depending on how you see it) the body was bitten off about 5 feet from the start of the dig.

Jacob driving a chalk-splitting chisel under the big jacket

How the specimen flipped in the field

Jacketing was a bit tough and we anticipated some problems with a huge flat jacket in soft weathered chalk. We feared a collapse (like that one other Xiphactinus I found a few years back that I nicknamed "Bea Arthur") so we did everything possible to try to get the specimen out safely. It still fell out, but to our amazement, almost all the bones remained in place in the jacket!

Show prepped main jacket

The rest of the jaws will go back in place later

Show prepping took a long time because of how soft the bones were. I got it into the "pretty enough" stage and now Nia is in storage, waiting for her turn to be turned into a spectacular panel mount.

Viva la Muppetfish! 2 new species of Rhinconichthys unleashed.

Bob Nicholls's excellent reconstruction of Rhinconichthys purgatoirensis

So, we've been working on a little public/private partnership project for the past 2 1/2 years here at the RMDRC. In 2013 while he was helping advise on our Megacephalosaurus eulerti skull restoration, Dr. Bruce Schumacher, a paleontologist from the US Forest Service, approached me with a fossil specimen he had collected from the Comanche National Grassland in Southeastern Colorado. From what he showed me, I could tell it was a pachycormid, and one of those toothless specimens I am so fond of preparing. I had never been so giddy about a fish head in a concretion before!

Kevin Lindahl as he discovered the specimen

The super informative pectoral fin, our first clue to its identity

Bruce had already done some basic prep work on the top of the fish. Some paperwork with my boss Mike Triebold was completed and we were under contract to finish preparing, molding and casting the specimen. I spent several hundred hours with air scribes and air abrasive blasters removing the extremely tenacious concretion surrounding the skull. What we found on the underside was astonishing.

Top of specimen showing nice skull roof

The underside showing googly eyes and super long lower jaw

The fish has a remarkably flappy underbite with relatively huge eyes. It reminded us of the character Beaker from "The Muppet Show," and the informal nickname "Muppetfish" stuck. Of course that name isn't going to fly in publication, so we named it as a new species, Rhinconichthys purgatoirensis, after the local landmark river. A second species, Rhinconichthys uyenoi from Japan, is also described and Rhinconichthys taylori from England is better described with new information from the Muppetfish Rosetta stone. When we released the 2010 paper on Bonnerichthys, these species were touched on briefly, but only R. taylori was complete enough to work on.

Why is this cool? Well, we've gone from one species in the genus from one place to having representatives from all across the Northern Hemisphere for several millions of years. It also shows that commercial paleo and federal agencies can work together to get stuff done, to the chagrin of some in the academic community. The specimen is to be permanently housed at the Denver Museum of Nature and Science.

You can find a copy of the paper here: http://www.sciencedirect.com/science/article/pii/S0195667115301427

Our newest little turtle: Jubal

Apparently TPI is the new home for the small turtles of the Niobrara chalk. We've already prepared, molded and cast our tiny Chelosphargis advena, Prepared a new Prionochelys matutina, and show prepped a nice Toxochelys latiremis that we discovered this past spring, all with nice skulls.

Our Prionochelys matutina specimen from MU5 (Coniacian)

You'd think that we would be content with our fossil turtle stash, but no. You can never have enough of these little guys. This week we prepared from start to finish another new specimen of a tiny protostegid from Kansas.

Box o rocks and bones

Preservation of the bones was beautiful, in nice hard yellow chalk so prep was an absolute joy. We didn't collect this specimen ourselves, which might explain the slightly unorthodox packing method employed in shipping the bones.

Plastron during preparation

While prepping the slabs we discovered many bones that were not apparent when work started. many of these surprise elements were adhered to adjacent bones by a thin layer of the oyster Pseudoperna congesta, making separation much more difficult.

Detail showing much of the pelvis in place

Amazingly, we are 4 for 4 this year for beautiful turtle heads. The skull block on this specimen contained not only all the major head bones, but also most of the hyoid apparatus. A very rare find in animals this small in the chalk.

Skull block before prep

Partly in thanks for helping us determine the identity of this turtle (the uber rare Chelosphargis advena), and partly just because we like him so dang much, we nicknamed RMDRC 15-001 "Jubal" in honor of Dr. Kraig Derstler of the University of New Orleans. For the back story, well you're just going to have to ask him about it.

Profile view of skull after prep

When finished with the prep, we did a layout and were shocked how complete this specimen really is. Next up is restoration, molding and casting so copies can be exhibited in museums and homes worldwide. The specimen is currently displayed in our lab viewing area, so come by soon and check it out before we put it all back together.

This is what a turtle looks like if you crack it open and pull everything out

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

Atractosteus from the Hell Creek

I feel a bit guilty. I found a gar specimen last year, in a soft sand, and I was afraid to prepare it. I had nightmares of thousands of bony scales floating loose in space. Well this week I finally took the plunge and started work. I've even been able to identify it to genus (I think). Let's start at the beginning.

June, 2012:

Hey look, a fossil! Toes for scale.

While prospecting in far western Harding County, SD for typical latest Cretaceous dinosaur fauna, Jacob and I climb a really high butte to GPS a Triceratops and see if it's on our landowner's property. No luck, it's a few dozen yards too far south. From up high we see a few very small low outcrops on our landowner's side of the fence that probably should be checked out. Jacob heads towards the pond, I trudge up to a sand blowout about 5 feet high at the most.

Scales in the field

The gar was just laying there in the flats. The scales caught my eye first, then I noticed the vertebrae, and the faint outline of a skull just barely coming to the surface.

Finishing the perimeter and consolidating

We treated the specimen like ones we dig up in Kansas: no need to expose any more, just find the perimeter. If you hit bone (or scales) just move on in a wider circle. The sand was so soft that we did all the work with mason's trowels. In about an hour or so, the site was perimetered.

Jacket's done!

I was fearful that no matter how good of a jacket we made, the thing in the loose sand would collapse out of it as we flipped the jacket, so I made the call to saturate the topside of the block with B-72 to harden it at least a bit. The hydrocal jacket was then applied directly to the rock, no separator being used. By lunchtime we had the jacket under control. Back in the lab, it sat under a workbench for over a year.

October 2013:
The specimen, now known as RMDRC 12-008, alternatively "ValDaGar" after my wife (plus it's really fun to shout), is brought out of storage. I figure it would be good to at least get the skull exposed, if it's there, before SVP. It'd suck to show up a second year in a row and tell researchers "no, we still haven't worked on it yet". After removing a few inches of sand (we dug deep JUST IN CASE) I finally hit something hard. Luckily it was bone, not the other side of the plaster jacket.

Here's where to start

Ok, I admit, it doesn't look pretty

Exposing the skull took surprisingly little time. I moved a bit further back to see if there was indeed articulated body. There was indeed. Every one of the hundreds of scales is getting prepared individually. I'll let the photos speak for themselves

Much better

The body slowly gets exposed

Side of face floated off a bit