Irrational attachment to field vehicles

During the summer, we spend a heck of a lot of time in our trucks. Since they're used off road in some pretty rough conditions, we try not to take anything new out there. It sure won't be new when it gets back. You get to know their quirks, and they seem to take on a personality of their own.

Here is my favorite: Dumpy the Suburban. Our oldest vehicle, this wonderful piece of 1991 technology is surprisingly one of the more durable and dependable field trucks we own, even with 220,500 miles on it. Deer kill markings on the drivers side are a tribute to the hazards of remote country roads at night. Dumpy has taken me all over the west over the past 5 years, yet never left us stuck or stranded. It's received scratches on the hood from angry locals, blown out tires and has tried to crush somebody. The huge dent on the door is from a deer at 65mph. Don't ask how it managed to hit the side.

Dumpy needs encouragement going uphill, usually sung to the tune of Aqua's "Barbie Girl". It moans on start up and smokes a little. Then again so do most of our field crew members at one time or another. But luckily, it has seemed to survive the cash for clunkers program (or as we like to call it, the Dumpycaust) unlike many of its cousins. If you see it rolling slowly around, make sure there is a driver in it, and wave. I will miss it when it is gone.

Prepping skin on WXT

A jacket of WXT, a huge Edmontosaurus specimen discovered in southern North Dakota 2002, was brought into the lab for preparation this past week. Before I could even begin, I noticed the scale pattern of the skin preserved as a film on one bone. Skin is uncommon but not unheard of in the Hell Creek Formation.

Further poking around showed scales preserved in the sandstone matrix in 3 dimensions. The scales themselves are only a few millimeters thick, and are preserved in a layer that will not separate easily. I'm now determining the extent of the skin present, and what should be done to it to best preserve it. The photo below shows one of the counterparts of the skin impression that was removed from the block.

Call for volunteers

So, you wanna dig dinosaurs?

We're looking for a few volunteers to come with us to central Montana this summer to help scout, recover the rest of our giant Basilemys turtle and begin excavation on a big hardosaur (the tibia is over 4 feet long). Our crew will be leaving from Colorado on July 28th, and will likely stay for 2 weeks. We will be headquartered out of a camping lodge, and there is no cost to volunteers besides transportation and food. All excavation equipment and supplies will be provided, personal tools are to be brought by each person attending. More on that after applications are reviewed.

Applications may be sent to me at anthony@rmdrc.com and should outline biology or geology experience. This trip is a wonderful way to gain experience for undergrad and graduate students in field collection methods. We will be focusing not only on excavation techniques, but data collection (mapping, stratigraphic sections and correlation, taphonomy) as well as site evaluation.

Introducing "Bev"

We have a new addition to the RMDRC mosasaur family: a Platecarpus ictericus from the upper Niobrara Chalk of Logan County, KS. I discovered this one on June 17th, but we didn't return to excavate till the 19th.

It appears to be a complete skull and cervical series, with a number of articulated dorsal vertebrae and ribs. The skull is scattered, but preserves not only all of the bones, but also calcified cartilage. This specimen is a great candidate for further preparation and 3d

mounting. Judging by the size of the lower jaws (18 inches) the complete animal would probably be 18 feet long. Unfortunately, scavenging sharks (probably Squalicorax kaupi, however a Cretoxyrhina mantelli tooth was also found on the same outcrop, rare in the upper chalk) forcibly removed the front limbs from Bev before she hit the bottom of the Western Interior Seaway 83 million years ago.

You may notice that we give nicknames to the specimens, and there is a great reason why. This mosasaur was discovered about 30 feet away from (and 15 minutes after) another Platecarpus specimen on the same outcrop. Instead of referring to them a "you know, the first mosasaur that Jacob found that week", we name them to keep them straight, both in the field and the lab.

The person that discovers the specimen gets the naming rights. In this case Bev is named after my mother. It's a great way of discovering which relatives like you best.

Fun in the chalk

It was a good trip...

We only got 2 days of scouting in before getting rained out of the field on Saturday, however we found some good new specimens. Jacob Jett was able to find his first mosasaur, a >Platecarpus specimen in the upper chalk of Logan County. I stumbled upon another mosasaur, >Platecarpus ictericus, about 30 feet further down the same gully, and elsewhere on the same private ranch I discovered the hips of a large diving bird, >Hesperornis.

Thursday we spent the day excavating a giant fish with Mike Everhart, currently identified as Protosphyraena gladius, however that seems likely to change in the next few years. It was extremely hot and humid, with the temperature at 7:00pm at 103 degrees. The photograph shows Mike Everhart, Jacob Jett and a little bit of Mike Triebold at the excavation site.

Friday and Saturday were spent excavating the >Platecarpus specimens, and all the fossils made it safely back to our lab. Be sure to stop by in the next month to watch us prepare these critters and more in our lab viewing area.

Off to the field!

No fossil of the week this time, our field crew will be headed off to the Niobrara Chalk in western Kansas bright and early Wednesday morning to investigate and recover more sea critters. I'll be taking lots of photographs so you can all see who's there and what we do, even some of the stuff we don't tell you about on our tours of the RMDRC.

Currently in the ground we have a small shark (probably Squalicorax falcatus), a small (12 foot) Xiphactinus audax, and a gigantic (18 foot plus) Xiphactinus that was partially poached from the rancher's property. Also, we'll be investigating a giant clam, Platyceramus, in hopes of putting it on display in our marine hall this summer. And who knows just what we may stumble upon once we start scouting!

Fossil of the week: 6/9/09

Let's talk big fish this week!

Ichthyodectid fish are amongst the most common fish found in the Niobrara chalk. The genera Prosaurodon, Saurodon, Saurocephalus, Gillicus, Ichthyodectes and the giant Xiphactinus are all found at various stratigraphic levels. Fish have very delicate skulls, however many times they are recovered articulated. It is impossible to disassemble these skulls without damaging them, so we usually prepare them in profile view. Sometimes they are disarticluated, looking like they reenacted the final scene from "Jaws 3D". These scattered skulls enable us to reassemble the pieces and take out some of the crushing distortion from 82-86 million years of burial.

The photo is of a specimen of Saurodon leanus named "Tony" that I discovered in Logan County, Kansas in October of 2006. Stratigraphically we're at about marker unit 18, so fairly high in the chalk, nearing the Pierre Shale contact. This is one of the more rare fish in the chalk, caricterized by it's long eel-like body and distinctive chin spike. As you can see, the bones of the skull have blown all apart, making this specimen a great candidate for molding and 3d reconstruction. No one is quite sure what the spike is used for, my guess is probing into the bottom muds of the western interior seaway looking for soft bodied invertebrates (such as worms) to eat. Hopefully we'll find more specimens in the future that may include stomach contents.