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!


Wednesday, August 24, 2016

We're still out doing fieldwork

The glamour of digging holes in the ground while battling flies and heatstroke. Come for the stuck side by side, stay for me breaking a 2x4 with my brute strength! Enjoy!


Friday, August 5, 2016

It's field season again

Wandering around Montana means lack of blog updates, but we're at least finding a few new dinosaurs. Here's a few good pictures from our first trip out to the badlands. Back out soon to work a few hadrosaur and ceratopsian sites in the blistering heat.
Big mother wolf spider with the kiddos

Dinosaurs hide everywhere

Jacob and I load a huge (4 foot plus) duckbill tibia into the truck

Sometimes the dinosaurs hide really well

Curatorial boot for scale, another duckbill site

Sometimes geology needs to be shown who's boss with power tools.

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, April 27, 2016

Daspletosaurus Assembly: Building a Frightful Lizard

There is actually a very good reason why I haven't updated this blog in a while: We've been up to our armpits in the lab building the prototype cast copy of Pete III, our 11m Daspletosaurus.
Ilium cast fresh in the mold

Progress is going quick by Academic standards, and we hope to finish the cast by early May.
Both feet before assembly

Jacob and I called "dibs" on making this skeleton, since we've been working on the project for 10 years.
We just admired this for a few days
It really is a great thing to see all this hard work finally amount to something tangible
Making the pubis. It is no longer blue
Plus everyone loves a huge tyrannosaur, especially one way more rare than T. rex.
Progress as of a few days ago. Tail is 17 feet (5.2m) long
Stay tuned for some more exciting progress really soon. We're finishing the neck, working out the gastral basket and have a few cervical ribs to go. 


Monday, February 8, 2016

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



Sunday, January 10, 2016

Everyone loves a little tail

Or even a huge one. Just wanted to share some cool pics we took of Pete III's 5.1m long (17 foot) tail. Caudal 1 is missing from this layout (it was still in the pelvis jacket), so add on another 18cm or so.

Not too shabby

Jacob, our living 2m scalebar

The Fossil Brewing Company shirt is apt