Showing posts with label Ceratopsian. Show all posts
Showing posts with label Ceratopsian. 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, 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

Thursday, March 26, 2015

Ava Restoration Update: March


Reconstruction of the skull started with 40 individual bones
Whether they are big or small, all ceratopsians sure do have a lot of parts. When they are juveniles like our Avaceratops, the lack of fusion in bones makes that even more apparent. For example, the sacrum (the wad of bones that holds up the rear end of the animal) in adults is usually one giant unwieldy piece. In our young animal, it is 26 individual parts, all with some degree of crushing, though not always in the same direction or degree.

Sacral neural spines molded
More of the massive piles of sacral parts
We've finished preparing the specimen and are busy restoring the individual bones to get molded. Restoration is a catch-all phrase that can mean anything from putting a protective layer of consolidant over the surface to sculpting missing bits to molding crushed vertebral centra, casting them, then cutting up the casts to re-inflate them to their appropriate size.
Most of the ribs, many crushed in strange directions

We're even using our trusty 3d scanning and printing equipment again to make precise mirror images of elements we are missing from one side to help complete the skeleton. In the end we'll end up with everything we need for a full sized standing cast skeleton, hopefully by Memorial Day.

Dorsal neural spines. Each one gets a centrum once restored.
Keep watching the updates on this blog for more news and pics of the restoration, molding and mounting project.



Wednesday, February 11, 2015

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.

Tuesday, January 28, 2014

Avaceratops skull finished - Tucson out the door

So, we here in the lab have survived yet another pre-Tucson Gem and Mineral Show crunch. Barely. This year we are exhibiting our casts at the 22nd Street Show. Come by and see our new stuff, like the Megalonyx, Enchodus, Stangerochampsa and our new Avaceratops.

Pinchy!
Never thought that pile of bones would turn out like this
Speaking of that, the prototype is finished! We molded the masters and then cast them using a rotational casting machine. Very lightweight! The finished skull is 1.05m (3'5") long from rostrum to end of parietal.

First run of the 3d model made from photographs
Very cute, and since the brow horns are pretty darn near symmetrical, their tweezer-like form is probably real. Very different than Nasutoceratops or even the MOR specimen of Avaceratops that Penkalski and Dodson described. What that means precisely is something for the experts to work out.

Human for sacle
The Enchodus is also pretty darn cool looking. Coming in at just 5 feet long (1.7m), it's one of the scariest looking little fish I've ever dug up.


Enchodus prototype

Stop by the booth and check out the specimens. And if you would like a copy of the Avaceratops, tell Mike I sent you. He;ll give you a good deal.


Monday, January 6, 2014

Avaceratops Skull Resto



Cast mount of the holotype Avaceratops in Philadelphia
So after a year and a half of digging and preparation, what do you do with a big pile of bones? Put them together! At long last, our Avaceratops project is moving forward and is surprisingly starting to look like something. Avaceratops is a fairly poorly known animal, with only 2 partial and fragmentary skulls discovered before this one. Ours is filling in lots of gaps since 1: we have more bones than were known before and 2: the bones that we have are more or less complete, not busted up. This adds a degree of difficulty to the project since all the restorations done before made a few educated assumptions about their missing bits, and not all of those were accurate.
An older bone map of the skull bones we thought we recovered, based on an image by Scott Hartmann
Jaw bones both real and 3d printed
Where to start though? In treating this like a giant model kit, we first decided to make all the parts we needed. There will be 60 individual bones to deal with. While we have the lions share of those, we do not have them all. The first step is to mold all the original elements and cast them in plastic. This enables us to mount them and take distortion out without destroying any of the real fossil. Second we identified all the elements that we had one side of and needed the other. Those elements were laser scanned, mirror imaged in software, then printed out in plastic on one of our 3d printers. Lastly, some elements were flat out missing. Those were fortunately few, but they ended up getting sculpted.
So, let's begin with some parts. Boot for scale
Once the parts were poured, we cut apart a few casts where the bones were glommed together and it was too dangerous to try to pry the fossils apart. After fitting a few parts, some needed to get cut or bent to fit how they were supposed to, taking millions of years of crushing and distortion out. This is much trickier than it sounds. Our frontals were squished just enough in the ground that when the brow horns were attached to the mount, the tips crossed each other. That's probably not how they went in life. The casts were then adhered together into subassemblies ready for molding.

Where we are today.
Work is still ongoing but we hope to be done in the next week or so with the heavy work. Once the molding is done, the final product will be just 5 parts. Much easier to put together than 60.


Tuesday, September 24, 2013

Prepping the Avaceratops

It's long overdue for an update, and since the weather in Montana isn't cooperating with our plans to head up there today and finish our season in the Judith River, it's as good a time as any to show what we've gotten done in the lab.

Newer modification to Scott Hartman's illustration: now with no nose horn
Work is slow due to the fact that the bone of this juvenile animal is fairly soft and crumbly when not consolidated, and that many bones are jackstrawed together in larger blocks. Each bone is individually removed from its jacket and checked against the field inventory. When it's a new bone, not exposed in the field excavation, we give it a separate accession number to keep track of it in the lab.

Jacket disassembly with documentation

Typical multi bone jacket before removal
We're primarily using air scribes on the "firm" sanstone matrix, with air abrasion for the detailed work. In some cases, such as the extensive skin impressions over the left hip and rib area, we skip the abrasion in order to preserve the skin as best we can.

Skin texture preserved on the right ilium
Once out of the rock, we restore the cracks and missing bits with epoxy putty in order to get the bones ready for molding. Our current plan, due to the completeness of the skull and skeleton, is to mold everything and do a full skeletal restoration. The animal looks like it will be less than 1.5m tall at the hips - very manageable for a ceratopsian.
Molding jaw parts prior to laser scanning