More Lambeosaur Fun

This week we've had a chance to begin work on the skull material recovered from RMRDRC 07-020 "Joyce", from the upper Judith River Formation of Fergus County, Montana. The material is typical for the Judith river... SOFT. We've begun utilizing the technique that I wrote about for the first FPCS at Petrified Forest National Park, in stabilizing he matrix and bone with low-strength adhesive (PB 4417) before air abrading the material. The results are great! I'd like to share a few pics of the first jacket we have prepared, and if anyone wants to take a well educated stab at the identity of the lambeosaurine, have at it!

Present is the right dentary in lingual view, as well as a quadrate and partial quadratojugal. 31 rows of teeth are present in this dental battery.

Freaking huge lambeosaurs of the Judith River Formation

It's always an exciting time when we come to the end of a project. Mostly because it's one of those rare times where we're finished with something. This week we're finishing the right leg from an exceptionally big lambeosaur (crested duckbill dinosaur) that was discovered this past summer in the Judith River Formation by Dr. Kraig Derstler. We were very excited at the time about the find since big articulated dinosaur legs usually lead to big articulated more complete dinosaurs. Usually.

Digging revealed that it was highly likely that the entire skeleton was present at one time in the late Cretaceous, however everything but this right leg (animal was probably laying on its right side) was eroded away during the Campanian. Oh well, it stings a little less when you know you're 78 million years too late.

We had help from some great ranchers and their newfangled power ATV things getting the specimen out of the bottom of the uncharacteristically wet gully. Without them, the leg would still probably be there riding out the winter. Above are ranchers Matt Wickens and Kerry Simac, with "field chef" Peter checking his gear. Below Jacob is pointing to the specimen, while rancher and dino finder extrordanaire Larry Tuss rests. I'm just sorta holding up the "outfit" as they call vehicles in Montana.

A few months later this is the result. A reasonably complete prepared leg. Missing the fibula, astragulus and calcaneum due to erosion, and the ungual on digit IV. The monster is 11 feet long (3.36 meters). Biiiig.

Joyce the Lambeosaur

Things are moving along well in the lab this winter, and one of our long term projects that we hope to tackle soon is the removal of the huge field jacket of RMDRC 07-022 "Joyce", a medium-sized crested duckbill from the Judith River Formation of central Montana. Joyce was discovered by rancher Larry Tuss on private land leased by TPI for fossil collecting, and is named after his lovely wife.

The dig was hot, and we were visited by film crews from Australian Broadcasting and NBC. The animal is moderately complete and partially articulated, however the tail was lost due to cretaceous erosion. Nothing like being 70 million years late to the party.

Currently the main jacket is being re-hydrated so that the matrix can be safely removed and the bones extracted from the middle of the prep lab. Photo above is the right lower jaw and part of the upper jaw. Any duckbill guys know if it's distinctive to genus level?

Disassembling Joyce

Well, we've finally made time.

Our Lambeosaurus, Joyce (RMDRC 07-020) is being prepared, partly because the dang main jacket (map above) is taking up way too much space in the prep area of the lab. The problem is that the bones are very difficult to separate. They are jackstrawed together, brittle, and now that all of the water has evaporated out of the jacket, the matrix is much harder.

The site with Kraig and Jacob while exposed for NBC camera crew.

Below is the main block before jacketing. Getting this apart is our newest challenge.

Fossil of the Week 5/2/09

For this week's dinosaur, we venture up to Montana and the Judith River Formation, 75 million years ago in the late Cretaceous. Larry, a rancher who loves to hunt for dinosaurs near his home, was exploring badlands with Dr. Kraig Derstler during the summer of 2007. He had just finished wagering Kraig the princely sum of 2 quarters that he could find a diggable dinosaur fossil first when he came across hadrosaur bone fragments weathering out of a very steep slope. A bit of excavation revealed a few bones clustered together, luckily a RMDRC field crew was already en route to Montana, and we would spend the next month at the site.

In the photo, Dr. Kraig Derstler and Paleo Tech Jacob Jett work on breaking up a large sandstone block above the dinosaur (under the white cloth near their feet). Small man-portable jackhammers help tremendously with digs like this.

Most of Joyce (Named after Larry's wife, whoever finds the dinosaur gets to name it) was buried fairly quickly, with only a few shed tyrannosaur teeth in the quarry indicating limited scavenging activity. Unfortunately, not long after Joyce was buried, a small creek had cut through the site removing most of the tail. Somehow knowing it had been missing for 75 million years made us feel a bit better. From the limbs, vertebrae and skull were were able to tell that it was a lambeosaurine duckbill dinosaur, one of the types with a head crest. The pile of bones was so extensive that we had to remove most of it in one large jacket, and slide it up nearly 50 feet of slope to load on a trailer. Preparation is ongoing, and we hope to have some bones on display in the coming months.

Joyce made her television debut in 2007 as well, with NBC Nightly News and ABC (Australia) both having camera crews visit us at the dig site.