Daspletosaurus prep update: now with arms

Hip block. Yowza.

I know I've spent a lot of my previous blog posts focusing on the Platecarpus skull we were getting ready to send off witht he travelling circus to Tucson. Well, they're out the door and I can swing my attention back to our Daspletosaurus "Pete III".

Need some claws

Preparation  is about 98% finished, with a few straggler parts and the pelvis block to finish up. We've also begun the restoration of some of the bones, partly for increased stability and partly because they're much less ugly now.  Mark Wildman posted on his blog recently a tidbit mentioning Daspletosaurus had the longest forelimbs of any tyrannosaurid. I'm not sure if that's correct, however comparing our measurements with others published for Tyrannosauurs rex, we're a bit longer overall, even though we estimate Pete III to be nearly 10 feet shorter in overall length than "Sue".

The beginning of restoration of the arms

One of the nice things about preparing and restoring these bones (finally) is that we can uncover some new information about Pete III. Based on the size of its femur, we can estimate it was around 20 years old when it died, which is pretty old for Daspletosaurus. I've starting to use "it" when referring to Pete III because one of the next mysteries I hope to solve is whether it was male or female. Stay tuned for updates!

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.

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.