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!





Friday, January 13, 2017

The Accidental Ichthyornis

Field identifications are problematic.

In mid October of this year the weather in Kansas was still warm enough to extend our dig season. That trip was pretty successful, finding a back half of a Protosphyraena and several small fish. Early on, Mike even thought he found another Pteranodon leg.
The drive to the site is a lot tougher when you can't see landmarks

We came out early in the morning. Man was it foggy. The entire day was supposed to be dedicated to finishing up excavation at several small sites. Since the "Pteranodon leg" site was so small, Mike and Jacob spearheaded the excavation there, while I wandered off to collect a Cimolichthys head and isolated Ichthyodectes site.
Several bones coming out at the site as discovered. Definitely not fish.

The "Pteranodon leg" showed some promising chunks of bone coming out, however inspection as they got down to the bone layer showed not a whole lot was there. Not like the large bones we were hoping to find for a Pterosaur.
That's a big hole for such a little block

Not a huge worry though, we perimeter the sites and very rarely expose the bone in the field, we will just find out what the "Pteranodon leg" looks like when we get back to the lab.
Jacob jackets and despairs as I tell him we have to go dig up another fish

Looking back at the video, just as Jacob began jacketing the specimen, I show up back at the site proudly announcing the discovery of the "Nia" Xiphactinus site that I blogged about last time. We all decided to drive over to the big fish and start work as the jacket cured. We were so stoked about the big fish that it was about a month later when we finally asked ourselves "Hey! Where did that jacket go?"

Turns out, we left it sitting there in the field, right next to a regularly visited oil well. Whoops! Over Christmas, Mike returned to the site to see if someone had poached it. Nope, the jacket was still exactly where we had left it. I guess you can say we got dang lucky. Let's never do that again.

Mike pulled it out and brought it back to the lab, where it sat for a week as I let it dry out (dry chalk behaves better than wet stuff when prepping, especially with small fossils). That's when the Eureka Moment happened: prepping down on the "Pteranodon leg" things weren't looking right. I immediately switched to my microscope, pin vise and very low pressure air abrasion (about 3psi with sodium bicarbonate blast media). My suspicions on the specimen's identity were confirmed when I found teeth. Pteranodon doesn't have teeth, but there's one small thing in the chalk with reptile-textured bone that does have it: a bird! Not only was it a bird, but the only complete articulated skull of Ichthyornis, who had been found only in fairly incomplete form since Marsh's days in the 1870s. This accidental and overlooked jacket suddenly turned into one of the rarest finds in the entire 160 year history of fossil hunting in the Niobrara.

Bird teeth, just a few milimeters long

Stay tuned for project updates as we work on this spectacular fossil.



Wednesday, December 21, 2016

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.




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