And now for something slightly different

You all deserve a brief respite from the dead fish and Avaceratops update barrage. What better excuse to talk about our big Daspletosaurus Pete III then? It's about the only dinosaur we have that people tend to ask about anyway. We've had an opportunity to catch up on a few projects lately and are able to spend some time in preparing the final few bones from their field jackets, while also restoring the skull bones to get them ready for 3d laser scanning and printing.

Bryan finishing the neural arch of caudal 2

I'm sure you have heard about the special challenges that preparing Pete III poses. I even did a paper on it, which is posted on my academia.edu page. When done, the bone itself is pretty stable, but it just looks somewhat ugly since it's made up of thousands of small fragments. We've adopted a technique using tinted hydrocal to fill in these small surface gaps to help give the bones a little more strength as well as make them look less pixellated (to borrow a term from a friend).

Left jugal after initial prep

Left jugal beginning restoration

Left jugal after finishing

Pixellated right quadratojugal

Much better with plaster

And in further comparison to the size of Pete III vs. Tyrannosaurus rex, here's a teaser comparing the left ectopterygoids of our Daspletosaurus vs a mounted copy of a rex. Not a whole lot of difference there overall.

Can't wait to get finished with this head...

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.

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.

Giant Oviraptor Tracks from the Hell Creek

It's been known for years that there are oviraptor-like dinosaurs found in the Hell Creek Formation. We find isolated elements mostly. A pubis here, a claw there. Small snapshots into their world, but they don't answer deeper questions like how big they got, how they moved, where they lived (instead of just where their remains ended up).

Skeleton of the new Hell Creek Ovi

In 1997 Mike Triebold was scouting on private land in Harding County, SD for dinosaurs. He came across a strange looking concretion. It looked a bit like a footprint, but as we know, concretions can take on all kinds of shapes. Looking closer, there was another concretion, in the same shape nearby. Then another and another, all in a line. A small excavation was started into the nearby outcrop, and the line of concretions continued. Though the overburden was getting too deep to chase them futher, it is likely there are even more still at the site. Mike recovered the specimens and made them available for research, which will be published on shortly.

Tracks in situ. The largest are nearly 60cm (2ft) across

Excavation of tracks

The concretions have now been identified as a preserved as the trackway of a giant North American oviraptorid, much larger than the specimens that we have skeletal remains for. The trackway shows how fast the animal was moving and even what kind of muck it was trudging through. We made molds and casts of the best ones, I'm thinking it may be a great addition to our ovi display in the exhibit hall.

3d scanner and printer up and running

After several years of fighting with technology, our 3d laser scanning program is up and running here at the RMDRC. We're currently scanning original specimens that are in the restoration queue in order to generate mirror image parts for missing bones. We started with simple parts on the Avaceratops including cranial and limb material, and progressed to more complicated things like the dentary and maxilla. Not satisfied with the amount of punishment we dished out on ourselves, we then tried Enchodus bits like the super thin premaxilla and operculum. They all turned out extremely well.

One of our new printers which works surprisingly well

Now that we have more complete sets of replicas to work with, our restoration of these specimens will be not only much more accurate but also faster.

Avaceratops lower jaw, with white 3d prints of actual material

Avaceratops tibia, split in a computer so it could fit in the printer

Next on the docket is some of the cranial material of our Daspletosaurus specimens. Donor parts from other animals will be brought in and scaled to size. Surprisingly easy to do with the software and operators we now have here. If you are out there and need some items scanned, give us a call!

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

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