Collecting a Xiphactinus: Kansas trip 2

Last week we went on a short trip to our Niobrara sites to collect a large specimen of Xiphactinus that was located by a 4H club member. Unfortunately the member had her boundaries confused, and found it on private property that she did not have permission to scout or collect on. Luckily though, we did. We still decided to nickname this fish "Lois" after the lady that discovered it.

Mike and Jacob in the hole, early in the morning

There was a lot of overburden to remove (volume-wise) because though the specimen wasn't deeply buried, it was spread 3 feet deep into the outcrop, along an exposure 9 feet long. A stirred up 15-17 foot fish is going to require a big hole, there's just no two ways about it. Hand tool digging was difficult, and we quickly escalated the equipment, first to an electric jackhammer (BTW I firmly believe everyone needs one of these things, they're awesome) and later to a bobcat excavator to knock down the bulk if the overburden.

The hole from another angle. Notice back-saving jackhammer!

We did this while it was still cool. Keep in mind this was one of the hottest days of the year. We awoke at 4:30 to get an early start. Funny thing: it doesn't get light this time of year in Gove County till 6:00 or so. Oops. No worries, we were pretty sure we could still get it out in one long day of work.

After bobcat work, expanding the hole to find the perimeter of the specimen

The fish itself was stirred up pretty severely, with the caudal fin exploded, spines everywhere, and the skull and pectoral girdle spread across the length of the excavation. On the bright side, this pile of bones will be a great basis for the restoration of the entire skeleton in a nice panel mount.

Dirty chainsaw work, with Jacob for scale

The stable pieces were removed and 2 jackets were carved out of the chalk with a chainsaw. 8:00 pm and we had it done. Only hit 95 degrees too. Much better than the 108 for a high the next day. I'm still exhausted from the experience.

Cleaning the undercuts in preparation for jacketing

Niobrara Trip #1 complete

Sorry it's been so long since the last blog post. Strange combination of field work and Chrome barfing the interface with Blogger on my end. Got it fixed now though. Hopefully.

Dumpy doesn't know if the sign is for the road or her

We went out last week on our first collection trip in the Niobrara Chalk of western Kansas last week, and had some great success. We went out with a class from the University of Tennessee Martin, and the students were a great help in covering outcrops that we hadn't looked at for a few years. The first recoverable item was found before the students had even arrived: a partial large Saurodon leanus skull, RMDRC 11-020. It was collected on a small knob really close to the surface with a plant on top. Roots did a number on it, but it is restorable as a plaque mount.

How many people does it take to jacket a mosasaur?

The second day of scouting with the whole compliment of people resulted in one of the students discovering a mosasaur skull, neck and partial torso coming out snout first of an outcrop low in the chalk (around MU 5), RMDRC 11-001. It looks to be a specimen of Platecarpus planifrons, with what appeared in the field as possible intraspecific bite marks across the snout. Ouch.

Standard TPI field pose

The next day we shifted over a section to the east and hit some outcrops that I had never scouted. The student that found the mosasaur managed to find a decent nearly complete Cimolichthys nepaholica, RMDRC 11-004, and not 30 yards away, an extremely large (9 foot long) Ichthyodectes ctenodon, RMDRC 11-018. Both animals were recovered. The Cimolichthys will be used in our 3D restoration project (which is ongoing) and the Ichthyodectes will be used to enhance our current 3D cast.

Perimitering the Cimolichthys before jacketing

The best part about it was that I was able to collect a few specimens for my pet research projects, including some Spinaptychus jaws, RMDRC 11-005-007 and a partial Martinichthys brevis skull, RMDRC 11-003. These rare little fish only appear to occur between MU 4 and MU 6 in the chalk, and material is pretty scarce, including skulls. Hooray for more data points!

Martinichthys snout!

Surprise jacket contents

Sometimes a bit of exploratory prep shows everything in the jacket. Sometimes there is more fun stuff buried deeper. We came across UTC's syncervical the other day. Sorta smooshed but still more or less recognizable. Hooray!

About halfway there

Jeez, UTC is very challenging prep. Slowly working through the very fragmented nature of the bone, but luckily the matrix is also fairly soft. We are, however, using a lot of consolidants to keep everything together. It's really interesting to see how things are taking shape now that we have prepared pieces that are starting to fit together, such as the right front arm. Below is a pic of the coracoid, humerus, ulna, meetacarpal and phalanx that we have finished.

Right arm taking shape, scapula still being prepared

After taking measurements and scaling them to the AMNH's Centrosaurus skeleton, it appears that our critter will be a hair over 6m long (19.5 feet) if it were complete.

Mid caudal... big, but no transverse processes

We're always working on a bunch of different things at the same time, so just for Saurian, we'd like to announce we've started baby steps towards working on our Daspletosaurus Pete III again. Jacob is working on a block that had a fibula, distal tarsal, and 5 articulated mid-caudal vertebrae in it. Hopefully by the end of the day tomorrow everything will be finished, and that's one more big jacket off of the shelf!

Pretty fibula!

Centrosaur prep binge

We begin week #2 of our prep efforts with renewed energy! The more we work on it, the more neat stuff we find. Case in point the jacket labelled "?tibia" turns out to be a complete right humerus, with a total length of 70cm. An ulna and fibula have also turned up, and field sketches seem to show a femur. This appears to be a fairly large centrosaur, approaching the size of our Triceratops prorsus skeleton "Gundy". If any of you researchers have good PDF references on centrosaurs, please contact me, I don't have library access so modern papers are relatively difficult to come by.

Right humerus

Ulna!

Other jackets are showing they have much more in them than what was recorded in the field notes. The jacket below looks to contain a predentary, several ribs, and a least one strange unknown (as of yet) element. We should know soon though!

All kinds of stuff in there.

Horn-faces and prep

We restarted work today on a dinosaur project that I'm actually pretty excited about. With the new discoveries from Utah, it looks more and more like the ceratopsian dinos of the Campanian are very specific to geographical area, in addition to stratigraphic level. For us working in the Judith River that means that you can maybe find Avaceratops and Monoclonius, according to the now seemingly dated conventional wisdom. Except that a new specimen of Ceratops montanus was recently discovered near our dig areas. And we've found things that look a heck of a lot like Anchiceratops. And Styracosaurus. And bits of a big honkin thing that looks a bit like the newly described Kosmoceratops. Oops. What a mess.

Dig site at the end of excavatoion

Typical jacket showing typical not falling down hill bone

The critter we're working on now is a centrosaurine nicknamed "UTC". It was discovered in 2004, and has sat on our shelves for much of the in-between time. It's time to knock out the prep. Unfortunately the specimen was discovered coming out skull first, with those parts slumping slowly downhill. It's going to be an interesting challenge getting it back together.

oooh epoccipitals!

The parts that we have are pretty interesting though, and as prep continues we may be able to get a good idea of what critter we have. Heck, based on the explosion of ceratiopsian discoveries in the past few years (and how most researchers avoid the Judith River Formation like the plague), there's even the possibility that this animal is a new species. We'll keep you updated on the progress as more bones get prepared.

Jonesing for mosasaurs

It's starting to feel a lot like springtime, which for us usually means trips to western Kansas to our Niobrara chalk localities. We haven't made it out yet (still waiting on that first downpour to wash the winter fluff off of the rocks... it may be a while with this drought) so instead I'll write a bit about a mosasaur that is near and dear to me.

Starting the hole

RMDRC 06-009 "Cap'n Chuck" was the first mosasaur I ever found. It's a specimen of Platecarpus "ictericus" (sorry Takuya, haven't made the species switch yet) from the upper chalk of Logan County, about 83 million years old. I spotted a single dorsal vertebra sticking out of a vertical gully wall, about 12 feet above the gully bottom. Don't ask what I was doing looking up there. My boss, Mike, loaded Jacob and I into the bucket of the bobcat and lifted us up to see if there was anything else there besides the single vertebra. Yep! we discovered the back of the skull, but since it was late October and in the low 50s (with drizzle coming in and lots of wind) we decided to secure the site till the next spring.

Jack-hammerin

In April of 2007 we returned, with a fancy new mini jackhammer that Mike had bought over the winter. Holy moly that thing saved us a lot of time.

We made this big of a hole in 3 days

Do you see the skull?

It turns out field mapping in the chalk is kind of a tough thing to do. The chalk gets all over everything and generally makes life miserable. It's best to save it for the lab. The skeleton was preserved very well, missing the end of the tail. Quick measurements of elements give us a total length of about 23 feet, which is pretty dang big for a Platecarpus.

Main jacket flipped and prepared. Things are much easier to see.

Once show-prepped in the lab it was decided that Cap'n Chuck was complete enough to restore in 3d (most exploded skulls are good candidates, there's less crushing distortion). That meant pulling every individual bone out of the jacket and cleaning it completely. This enabled us to get a good look at some rare parts like the interclavicle and ear cartilages. Hopefully we'll be able to start restoration sooner or later!

Laid back