Showing posts with label RMDRC. Show all posts
Showing posts with label RMDRC. Show all posts

Friday, May 10, 2019

Project Kevin Part 2: The Kevining

Project Kevin is complete (for now, we have to invent a body and that might be... interesting)! The last time I updated this, I had left you at "We dug stuff up and were making it as pretty as it could be" in the lab. That left us with a pile of neat looking bones, but of course we wanted more. Did we have enough to make a skull? And if so, what did it look like? We sure thought we did based on what we identified, though since the site was trampled int he Cretaceous most bones were missing chunks.
One of the mostly complete brow horns

First things first though. Let's laser scan (alright not a laser, but an Artec Spider structured light scanner) all the things! This gives us a good baseline to record what we have. These scans can also be shared with interested researchers across the planet. Researchers are usually pretty happy giving opinions of things and many helped us with details on how this thing might come back together.
Right maxilla in digital form

We can also try out new things with the scans. I came up with an interesting idea to print a 30% scale model of all the parts (using mirrored parts if one side was missing or just incomplete/really ugly). We popped off the parts on our Formlabs Form2 (the 30% scale was determined by the size of the build plate of the printer, these SLA printers can be pretty small) and tried to put together a model to guide us. We goofed though.
The first draft, complete with all our errors

Turns out we had the brow horns on backwards. Also the fits between the bones weren't as accurate as we would have liked. So we fixed them on a small scale before committing on the casts and prints of the full scale stuff. It also gave us the ability to try out things like a scaled and computationally-squished rostrum to make a part that we were completely missing. In this case we printed out a bunch of different possibilities and fit them on until we had a result that looked plausible.
Second draft of scale model, now we get to try out different beaks

With this information in hand, 4 binders of papers as references and a pile of casts, we were ready to take a stab at reconstructing the skull. Lainie and Grace really did a heck of a job learning these techniques. Printing out full size mirrored parts make the skull more accurate and easier to reassemble than if we were to sculpt the missing bits from scratch.
3D prints, casts, lots of epoxy putty and Bondo. Lainie for scale

Things went pretty smoothly till someone (who shall remain nameless) suggested our minimum length conservative frill was probably much too short. The first draft was based only on the length of the frill parts that were preserved. Chasmosaurines like this have seriously long frills though so we took their advice and busted out the sawzall. It was only plastic after all.
OK, let's move this frill about a foot to the back I really think it looks better this way.

We also had to make teeth. Hydrospan 100 was wonderful for this. We poured it into a mold of Ava (RMDRC 12-020)'s dentary and made a floppy cast. This material was then soaked in water until it expanded enough to fit the tooth rows for Kevin. Then we molded it, poured a bunch of plastic copies and played dinosaur dentist for a few days getting over 100 rows of teeth in all the jaws.

We molded all the finished parts and made casts. The skull was cut apart to make the molding process easier. A single mold for the top of the skull would have been huge, complicated and really heavy.
This is what a Kevin skull kit would contain if you bought one

Grace and Lainie making a huge mold for the frill

We put the prototype together in just a few days. It was a lot bigger than we expected. But after paint and finishing, I thought it went together pretty well! Technology really helped us out on this one, saving us materials, time and most importantly effort. I don't think we could have gotten it done by the deadline without it. Now it's time to figure out where this belongs in the family tree.
The prototype is done!

And the obligatory "Curator for scale" photo. I forgot to suck in my gut.
Here's what we put together for the left side, and where we got it from.


Thursday, February 14, 2019

Project Kevin Part 1: Field and Lab Work

The astute social media observers among you may have noticed our new ceratopsian whose skull restoration was just finished in time for its debut at Tucson. Here's how we got it there in 2 parts. Today: the hot and nasty work.
Yep, that's hot
The site was originally discovered in the summer of 2017 by one of our landowners, rancher buddies and all around good guy Larry in the upper Judith River Formation of central Montana. We located a partial humerus, a lot of ribs and several vertebrae exposed on the erosional surface right away. The entire deposit was constricted to about 15cm (6 inches) of highly concreted sandstone, and from the exposed highly eroded elements we could tell it was from an ornithischian of some flavor. Odds were it was probably an incomplete scattered duckbill in fairly difficult to work matrix, so we decided to keep scouting and come back later.
The site is very remote but also gorgeous
That later turned out to be the summer of 2018. It was hot. Really hot. Continued scouting in that area turned up some pretty neat lag deposits but not a whole lot of good skeletal material. It was time to bite the bullet and see what the old duckbill site was going to give us. Who knows, there might be a skull in there.
Digging begins. We love our shade tents.

Sometimes we get visitors to the site

With 4 people digging we made some good progress on the first day of the dig. Around lunchtime I had moseyed on up to the top of a nearby bluff to get cell signal to call home to the boss and give him an update on how we weren't finding anything great out there and might relocate our scouting locality to somewhere closer to camp. Coming back to the site I ran into Jacob who was looking for me to let me know we had "the weirdest duckbill he's ever seen" in the quarry.
That ain't no duckbill horn.
Grace had found a brow horn.
Lainie demonstrates proper air hammer technique.
So, not a duckbill (though to be fair we did find some scattered hadrosaur material at the site). We dug more that week finding much more skull material, but had to come home for resupply and other projects. We got smart during trip #2 and brought out some diesel powered earth moving equipment as the overburden went from practically zero to nearly 3 meters very quickly. Again more skull material was found. There was some postcrania too but we all know that ceratopsian postcrania is pretty much worthless, right?
Bobcat good, getting hit by 2 dust devils in a row bad for shade tents
After the 3rd trip, the bone was very sparse along all edges of the excavation and we were pretty confident to call the dig finished.
Headed home with a load of jackets. Rock Chalk!
Lab work began right away. There were a few tricky bits getting the nasty concretion off the bones but for the most part they came out looking pretty good. Once cleaned up we got a much better idea of what parts of the skull we had (field identifications are always tentative). It also became pretty obvious the skeleton was trampled by other very inconsiderate dinosaurs way back in the cretaceous, as we had many broken bones with no parts to go back with them.
Right brow horn, missing some parts, but we can fix that.
Bone quality was pretty good and we ended up with most of the skull, quite a bit of the neck, some dorsal vertebrae and ribs, and curiously a random chunk of pubis.
Detail of jugal edge. Beautiful bone texture.
Stay tuned for the next installment where we show how we went from a pile of bones to a completed skull restoration in 100 easy steps!

Wednesday, May 3, 2017

First Kansas Trip in the Bag - 2017

For the first time in a few years, we've been able to hit the Niobrara outcrops in the spring! Holy crap was it cold. The last day out, I don't think it got above 50 degrees, not that the 40mph winds would make it feel any warmer. Perfectly miserable. And just like clockwork, on our last day, as the sun was setting behind a large row of thunderstorms on the horizon, we found the best skeleton of the trip! The rest of the time was staring at blank ground finding fossil poop.

Look at this swirly poop!
I entertained myself by finding a "nice" Xiphactinus tail. I was instructing a new hire on how to actually find fossils in pretty bleak badlands when I saw just a small fragment of tail fin coming out of the rock. I'm happy I found this one as since we have SO MANY Xiphactinus specimens in storage, we've implemented a "one in, one out" policy on these fish and I've somewhat jokingly insinuated firing anyone that finds another of these darn fish. Our newbies were safe.
Well, there's a fish tail

Jesse using a chainsaw to trench around the fossil
When you find weathered out fish tail chunks, you have to chase them in (even if they're "just" a Xiphactinus). Sometimes the rest of the tail is there. Sometimes there's the rest of a 15 foot long fish attached to it. Sometimes it just ends. In this case, we found a perfect lower lobe of the fin, but no body. As far as we were from the truck, I'm happy we didn't have to make a huge jacket, since those are heavy and I'm getting lazy in my old age.
Trenching complete, curatorial boot for scale

Jacketing complete and ready to flip, other curatorial boot for scale
Popping it out and prepping it was also quick. Measuring the vertebrae we found it's the exact same size to complete another Xiphactinus specimen we excavated 3 years ago (which just happened to be missing the tail). This will help us out tremendously when we panel mount the animal in the near future.
Not too shabby!
Other stuff was less plentiful on this first trip, but we were lucky enough to find parts of 3 sea turtles, which is always really nice.
Jesse and grace entrusted with power tools to get to a turtle
And of course at the very last minute, Jesse stumbled on a pretty complete Clidastes skull in an outcrop near where we discovered our gigantic 17 foot Xiphactinus specimen 20 years ago. We worked very hard to excavate the specimen with daylight fading and weather bearing down on us.
Jesse and grace getting Clidastes block ready for jacketing
The specimen was safely loaded in the truck by headlight, which also made for a really interesting drive through farm fields in the dark at the end of a 14 hour day. Prep is going on right now, so stay tuned to see how this cute little mosasaur turns out!





Thursday, November 10, 2016

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!


Friday, May 27, 2016

Pete III finished. For now.

Just for the weekend, the prototype cast of our Daspletosaurus Pete III (RMDRC 06-005) will be shown off in the atrium of the museum, before it gets decent photographs and heads to its forever home. Yes, it has a 2006 specimen number.
The original site as found/explored in July 2005. We were so young.

We've been working on this for a decade. I'm not sure if I should take the day off to celebrate, or take advantage of the free time of getting a huge project off my plate and start something new and exciting. In the meantime, enjoy some of the snowy photos, better well-lit ones to come in a week.

So, this is what a pile of Daspletosaurus looks like

It just looks like such a fast critter, not like dumpy Tyrannosaurus

Nearly 11m of birdy goodness

Wednesday, September 16, 2015

Please welcome the new "Avaceratops"

It's a happy day when we get to unleash a brand new dinosaur on the world. After 3 years of hard work and a lot of sweat, we get to show off our new primitive centrosaurine ceratopsian!
The newest skeletal, copyright Scott Hartman, used with permission

The skelton in all it's glory, Curator for scale
The bones of the specimen that were recovered, copyright Scott Hartman, used with permission

We discovered the specimen at the end of August 2012 on private land in central Montana. The specimen was found near the top of the Judith River Formation, in rocks approximately 75 million years old. You may notice we are using the name "Avaceratops" in quotes here. We're not trying to be coy or mysterious, but with the stratigraphic difference (our specimen is about 3 million years younger than the holotype) and the differences in skull morphology highlighted below, we have come to the conclusion that this is a different animal than true Avaceratops lammersi.

Someone put a lot of work into this. Tell me who you are so I can give credit!
The skull is quite different in detail. It totally lacks a nose horn, and the long brow horns (until recently a rarity in centrosaurine ceratopsians) point forward and even slightly back towards each other, much different than the other two known skulls. It's large "forehead" area is more reminiscent of the recently described Nasutoceratops, from about the same time in Utah.

Overall, the skeleton is 3.5m long and about 1.2m tall. We estimate the critter was about 3 to 4 years old when it died, both based on its relatively small size and the extensive lack of fusion in its skeletal elements. It's pelvis was reassembled from over 30 separate elements. What a job.
Digging down into the quarry site

After the dinosaur died, it's partially mummified body washed down a stream channel until it hit a logjam composed of not only actual logs, but the limb bones of a large hadrosaur. Here it lodged upside down and then began to partially disarticulate. Some of the dried skin over the hips was surprisingly well preserved though, as addressed in an earlier blog post. A few tyrannosaur teeth were found at the site, but we feel those were incidental background fossils, as no predation or scavenging marks were observed on the bones.

Tyrannosaur tooth found at the site

After all this painstaking work in sometimes miserable conditions, we are excited to share the product of this discovery with the rest of the world. After getting unveiled to the press on Wednesday, September 16 at 10:00am the mounted skeleton will be on display at the RMDRC for just a few weeks before making its first trip to Dallas, TX for the 75th meeting of the Society of Vertebrate Paleontology. You must come see it!
The mount showing the horn shapes (and absences)

Rear view of skeleton

Wednesday, May 27, 2015

Our Xiphactinus dig featured on River Monsters: backstory

I really hope everyone got a chance to see the River Monsters season finale. Here's a teaser of Jeremy Wade Sharing a bit of what he had learned with us in the field digging up a Xiphactinus audax skeleton.


One of the things he alludes to has a funny backstory. When we first arrived at the site, the film crew's rental minivans couldn't get near where all the equipment needed to be. Not a huge problem, we transferred it to the bed of the bosses truck and away went the gear and most of the crew. I had been riding in vehicles way too much already that morning and decided I'd walk the easy 1/4 mile or so left to the site. Jeremy, the director and an assistant decided this was a good idea as well, so I was able to show them some things in the chalk on the way up. Mostly clams. Lots and lots of clams.
The site is on the opposite side of the butte in the background
Arriving near the digsite site, literally within 4 feet of where the boss parked the truck, while talking to Jeremy about how you have to be in the right place at the right time to find a specimen, I look down and see the face of a newly eroding Xiphactinus specimen poking out of the rock. I COULD NOT HAVE PLANNED IT BETTER. It's really not all that great, but our guests had never seen the discovery of a fossil before, and they seemed pretty thrilled about it. Happy I could oblige.
Can you see it? It's a beauty!
Back in the lab the next day we worked hard to begin the prep on the Xiphactinus specimen RMDRC 14-012, which we nicknamed "Jeremy". Unfortunately, all of that seems to have ended up on the cutting room floor.
Just a few people watching over my shoulder as I prep
Nevertheless, we went ahead and finished prep on "Jeremy". Not the prettiest one, and for the life of me I can't figure out how the face was nicely articulated but the entire braincase was spun off and away. Them's the breaks I guess. As for working with the River Monsters crew again? Name the time and place, they were superb.
I've seen worse

Sclerotics in place still!