Explodosaurus redux

Just taking an opportunity to update the project before we get buried with snow. Lower jaws are on and positioned, but I still have to finish the braincase and palate.... then on to fixing the whole total lack of teeth problem. Top of skull is 40.5cm long. Such a cute little Tylosaurus.

Explodosaurus reconstruction

Earlier this summer paleo tech Jacob Jett happened upon the exploded out skull of a small Tylosaurus kansasensis specimen in Lane County, KS. I would have found it first, but I was distracted watching a couple of bulls fighting a few hundred feet away while simultaneously noticing the lack of a fenceline between us and them.

Yes, that pile of rubble is the specimen.

It's taken a lot of puzzlework to get the pieces back together, but they are looking better every day. The skull will end up being under 17 inches long when finished. Most bones are still present and I am actually a bit shocked how much of it has fit. Now, how to get the bleached bone to look like the in situ material....

Patting ourselves on the back

Discover Magazine came out with their list of "The Top 100 Discoveries of 2010"

We came in at #50 with our Bonnerichthys paper that came out in Science in February.

I can't reveal much more yet, but there is further exciting research happening with this critter, so stay tuned.

And lastly: the Sternberg Museum in Hays, KS is putting their Bonnerichthys gladius specimen (that RMDRC helped collect and prepare) on public display starting this weekend, so be sure to stop in and say "Hi"!

http://discover.coverleaf.com/discovermagazine/201101?pg=59#pg59

DRAMATIC MUSIC TIME!

Perhaps it's best to hit mute.

Saurodon finally reconstructed!

In the 3+ weeks we've been working on this project, I never thought we'd finish before I left for thanksgiving break. I use the term loosely, the skeleton still needs paint and detailing. We'll be bringing it to Tucson, and in the meantime it will be proudly displayed in our marine hall for all to see when they visit the RMDRC.

Saurodon Reconstruction Update 2

We've been molding quickly.Yhere are a lot of pieces to this critter. Missing bits are being reconstructed based off of our Ichthyodectes cast skeleton. Cast vertebrae are being remolded (this animal seems to have 115-120 vertebrae) and ribs/spines are being manufactured as fast as we can make them. Assembly should begin sometime next week.The fish itself is 13% larger than the famous articulated Saurodon specimen that Marion Bonner discovered, which is at the LACM. A quick bit of scribbly math puts us at a total length of about 8 1/2 feet, with a skull at over 19 inches long. It's a lot bigger than I assumed based on the pile of bones we began the project with.

Below is the right dentary, that had damaged/missing teeth in the center. We molded the left dentary and used cast copies of the teeth to reconstruct the missing bits. The more I work with this thing, the weirder this critter becomes.

3 Dimensionalizing a Saurodon

Finally an update on a specimen I discovered back in 2006. Tony I (named after my father) is a completely exploded Saurodon skull and pectoral fin assembly. Saurodon is an ichthyodectid fish (related to Xiphactinus, Saurocephalus, Gillicus, Ichthyodectes and of course Prosaurodon) that had a peculiar chin spike, in this case over 6cm long. The teeth are like mini flat knife blades. This specimen was discovered disarticulated at about MU 18-19 in the Niobrara Chalk of Logan County, Kansas. The locality is surprisingly high in the Niobrara, I have found several specimens of a later relative (Saurocephalus lanciformis) in the rock layers immediately above this specimen. Below you can see the predentary along with one of the premaxillas.Nasty, but luckily not articulated like the majority of Saurodon leanus specimens in other institutions. No, Tony I looked like it swallowed a hand grenade, kinda like the ending of the movie Jaws 3. That's just how we like to find them. Preparation shows that the majority of the skull is present. The missing bits will be reconstructed based off of our Ichthyodectes ctenodon reconstruction. Be sure to stop by the museum and check in on the project. We hope to have the prototype skull assembled by Thanksgiving!

Martinichthys bonanza

It appears that our field season in Kansas is about finished for the year. Last week Mike Triebold, Jacob Jett and I went out to Gove County to explore in the lower Niobrara. Collecting was pretty sparse, Jacob and I dug a fairly sizable dry hole looking for the source of a mosasaur. We also collected the partial skull of a very small Tylosaurus that Mike found. Mike also found some fish material and a chunky Pteranodon wing. Jacob's typical luck held up. I wouldn't call it a bust with those results, but luckily I stumbled across a very rare fish skull that made the whole trip worthwhile for me.

Martinichthys is a strange plethodid fish with a characteristic blunt rostrum. Prior to this field season only 2 relatively complete skulls were known. In June I discovered RMDRC 10-024 from around MU 6, which I was excited about. This trip I found RMDRC 10-031 from slightly lower, right on MU 5, thereby doubling the known specimens. 10-031 is interesting because not only does it preserve the skull, but also vertebrae and epineurals. Below are both skulls. They may not look very pretty, but we're excited about them here! A great year for this new fish.

Mosasaur skin prep

Recently Dr. Johan Lindgren of the University of Lund, Sweden visited our lab to look at our mosasaur collection. He has just published a paper with colleagues on soft tissue preservation in the mosasaur Platecarpus from western Kansas, available here. I had noticed some non-descriptive"smears" around the skull of our Tylosaurus nepaeolicus specimen "Tracie" RMDRC 08-002 while preparing it, and thought it warranted further investigation. We removed the specimen temporarily from display and I brought it into the clean room for further preparation. This was important so that I could shut off the lights. Why on earth would I want to do that?

Simple: The phosphatized remains of mosasaur skin will glow under blacklight! They are much more visible than under natural light and it makes preparation easier.

Preparation was fairly difficult, but we may have discovered the first skin preserved from the head region of a Tylosaurus ever. I'm currently writing a paper on the preparation techniques involved, so stay tuned for updates soon!

New Book by Greg Paul

I've just been sent a copy of Gregory S. Paul's new book, The Princeton Field Guide to Dinosaurs! The 320 page hardcover volume is jam-packed with over 600 illustrations of over 735 different types of dinosaurs, many of which even I have not heard of before. Skeletal reconstructions are supplemented with color pencil illustrations and in a few cases stunning environmental reconstructions. I must admit there is a huge amount of information packed into this book, and even a hyper-dino-nerd like me has not had a chance to read every single word of it yet. Luckily it is very heavily illustrated, for those of us that cheat by looking at pictures.

The book begins with a 65 page section of text and illustration covering dinosaur research, anatomy and biology. After that it dives headlong into the dinosaurs, arranged by type. Not surprisingly the theropods are first. Each species of dinosaur is listed with a brief description giving their size, how much of the animal is known, distinguishing characteristics, age, distribution and some special notes. Several of TPI's dinosaur specimens are illustrated including "Sandy" the Pachycephalosaurus and "C1/C2" the unnamed North American oviraptor now housed at the Carnegie Museum.

Paul takes some liberties with the taxonomic assignments, seemingly destroying some types of dinosaurs and ruining people's childhoods in the process, however this is a general interest book, not intended for use by scholars. Parents with children interested in dinosaurs may have to spend some time explaining what happened to Lambeosaurus, Torosaurus or even Daspletosaurus. And then there is the seeming revival of Brontosaurus, an issue that sometimes makes me want to pull out what little hair I have left! On the bright side there is elimination of Opisthocoelocaudia, so at least we don't have to stumble through that name anymore.

Would I recommend this book? Most certainly! It is leaps and bounds better than the stuff I had available to me as a child, and it would have kept my interest for days on the first read-through. The price is right too at $35.00, and can be found online for even less. If you're a parent that has a dino-lover in the family, this would make an excellent holiday gift!

The Reassembly of Dillon III- Finished

After a final binge of puttywork and painting of the restored/donor plastic pieces, our Platecarpus sp. RMDRC 10-007 "Dillon" is ready for its public debut. Be sure to check it out this week in Denver at the Coliseum Gem and Mineral Show.

The Reassembly of Dillon II- Mosasaur Boogaloo

The Mosa-tissarie is alive and well. Back from the field (more on that in another post) and right into the final push of this project! The lower jaws are now mounted although still a bit wonky. Just about everything is in place and now it is time for the final restoration of the teeth, braincase and pterygoids. The last step will be painting all the restoration to match the original fossil color. Be sure to come visit it at the RMDRC before it heads off to the Denver Coliseum show next week.

The Reassembly of Dillon

The squished incomplete and partially disarticulated Platecarpus sp. skull is coming back together! It's taking a lot of time and some hefty restoration, however it does indeed now look like something!

The top of the skull has a welded steel support frame holding everything together. Lower jaws will be removable for shipping but also are attached to a steel superstructure. All missing parts are based off of our Platecarpus planifrons cast, including the donor braincase (which is an odd thing to go missing on a skull and neck this complete). Next up is mounting the 5 cervical vertebrae recovered with the specimen and final detail/paint work. Hopefully it will all be finished shortly after Labor day!

Basilemys reconstruction

In 2007, a friend of Dr. Kraig Derstler accompanied TPI crews doing field recon in the Judith River Formation of central Montana. In one gully he discovered some very large turtle shell parts coming out, and we traced them to their source. Though obviously belonging to the "emperor turtle" Basilemys, this turtle looks as if it had swallowed a hand grenade, where all parts were disarticulated and spread through the outcrop.

Excavation was conducted in 2007 and 2008 (and even a bit in 2009), and about 50% of the animal was recovered. Since the specimen, now nicknamed "Doug" after the discoverer, is disarticulated, this gives us a great opportunity to reconstruct the specimen in inflated form, as opposed to the crushed articulated specimens found until now.

This specimen is also remarkable because it preserves several non-shell skeletal elements, which is rare for this type. These include both pelvis assemblies, scapula, dorsal vertebra #1 and toes. An isolated Basilemys humerus found on a nearby ranch will also be used in the reconstruction. Stop on by the museum to see how the project is coming over the next few months!

More Cephalopod Fun

Throwing a bone to the invertebrate guys out there, here's new images of RMDRC 10-018 Spinaptychus sp. that yours truly found earlier this spring in Gove Co., Kansas. Ammonite remains are fairly rare in the chalk since the aragonitic shells do not readily preserve. These jaw parts however are calcitic in nature, and are occasionally found. We lent this specimen to Neal Larson of Black Hills Institute for detailed preparation and a bit of restoration before molding. He and his staff did an absolutely phenomenal job. Thanks again, neal!

The specimen is fairly large at over 5 inches wide, 4 inches long. The next project is determining what ammonite this specimen belongs to. Hopefully a paper will be coming out soon!

The Disassembly of Dillon

Back in April of this year Paleotech Jacob Jett discovered a small mosasaur in the upper Niobrara Chalk of Logan County, Kansas. This critter, a Platecarpus (RMDRC 10-007) consisted of a skull and 5 cervical vertebrae. Part of the upper jaws were exposed at the surface, and there was extensive calciteAbove, Jacob works on preliminary excavation immediately after locating the specimen. Luckily there was little present in the way of overburden.
A few hours later, Jacob has found the perimeter of the specimen (he finally discovered something, so I went to search other areas of the outcrop, finding the big Clidastes Tony II RMDRC 10-008). The entire exposed area will be covered with a plaster and burlap jacket to transport back to the lab. Unfortunately, after the jacket was made, the area was hit with torrential rains (6 inches in 24 hours) and we were not able to get back to the jacket to bring it home. It had to sit out exposed to the elements for 2 weeks.
The jacket was "show prepped" (prepared to expose what is present) once it returned to the lab. As you can see, most of the skull is there, missing only parts of the left maxilla and for some strange reason, the braincase! I am currently in the process of getting these heavily concreted bones separated so that Dillon can be reassembled as a 3d skull and neck mount. As you can guess, it is a time-consuming and delicate process, and the results will be shown in the next blog update.

More on Gil

Show prep is continuing on our duckbill! Time for a little background information. Gil, AKA RMDRC 04-001, was discovered in 2004 by and is named in memory of "JC" John Cully Gilpatric, who sadly passed away 2 years ago. It comes from the upper Judith River Formation, putting its age somewhere around 75 million years old. Excavation began on June 26, 2004 and had been completed by July 2nd. Gil wad found in a fairly soft sandstone with low overburden, which greatly sped up the recovery.

Above is a sketch of the site when TPI field crews excavated it that summer. As you can see it is highly articulated but missing the skull and lower legs. Unfortunately for hadrosaurine hadrosaurs those also happen to be the most distinctive parts, so identification down to genus is still a little tentative. We have been considering Gil to beling to Miasaura, however there exists the possibility that It could belong to two other non-crested duckbills that existed at the same time: Gryposaurus or Prosaurolophus. Below is a photo of the 54cm long right humerus, which may or may not be distinctive. In any case it's pretty, and also slightly longer than the radius.Prep work is ongoing to find more distinctive skeletal elements, so that we may get a better idea of the true identity of this critter. Special thanks goes out to Dr. James Kirkland for providing PDF reprints so that I may attempt to clear this up!

Duckbill tails from the past!

We've been able to do a slight bit of preparation on a Maiasaura that was collected by TPI crews in 2004 from the upper Judith River Fm of Montana. Unfortunately no skin was discovered preserved in this jacket, however there were a few surprises.

The anterior 6 vertebrae show pathological neural spines, perhaps an old bite wound that healed. The chevrons (Y-shaped bones under the tail) are tiny, much smaller than what would normally be expected on a dukbill of this size.

This jacket contains 32 articulated caudal vertebrae in a string nearly 8 feet long. Strangely the chevrons are all nearly gone and the ossified ligaments normally found in ornithischian dinosaurs are completely missing.

And now for a rare one: Martinichthys

Even though the past two (hot) expeditions to Kansas have been primarily aimed at recovering various Xiphactinus skeletons that we have discovered over the years, we did have a little time to scout some outcrops low in the Niobrara chalk. Last Monday, I stumbled across some fish skull parts on an outcrop and followed them up to their source. This is what was coming out:

The rostrum of this rare fish is the most commonly discovered part recovered, mostly because it is the densest and most durable bit, and most likely to be found after weathering out of the outcrop. The teeth are tiny and resemble small barbs, though they number in the thousands. We may have found postcranial material with this fish as well, and a recovery operation at the site will be attempted next time we go to Kansas, though that may be a few months.

Martinichtys seems to have gone extinct between Marker units 5 and 6 (this specimen is the highest one I can find data for, about 1m below MU 6), as do several other animals int he Niobrara (such as Thryptodus, Tylosaurus kansasensis, and several invertebrates). I am curious what happened to wipe these species out.

Meet Tony II!

Well, field season started off with a bang this year. The little mosasaur snout I found in late April turned out to be a nearly complete specimen of Clidastes c.f. moorevillensis, which isn't really supposed to be in the chalk. The critter measures 4.8m long (16 feet), and is so well preserved that it retains cartilage in the ear, sternum, sternal ribs and above the scapulas.
Above, Mike Triebold uses a chainsaw with a special blade to separate the block away from the outcrop prior to jacketing. This chalk was the hardest we've ever encounterred in nearly 3 decades of collecting in the Niobrara.

The site as seen from the top of an adjacent bluff. Luckily we could drive up to the site to dropp off air compressors and generators!

Below is the prepared front half of the animal. 45cm (18 inches) of backbone was lost in the mid dorsal section due to erosion years ago. The tail section was taken out in another large jacket. Come see the specimen, now on display in our marine hall at the RMDRC!

RMDRC gets published!

A small project that I've been involved in for a few years, the discovery of the first heteromorph (open coiled) ammonite from the Niobrara Chalk.

Citation:

Everhart, M.J. and Maltese, A. 2010. First report of a heteromorph ammonite, cf. Glyptoxoceras, from the Smoky Hill Chalk (Santonian) of western Kansas, and a brief review of Niobrara cephalopods. Kansas Academy of Science, Transactions 113:(1-2):64-70.

We discovered the specimen while excavating the "Tracie" Tylosaurus nepaeolicus specimen in June 2008. Triebold Paleontology Inc. donated the ammonite to the Sternberg Museum at Fort Hays State University in 2009 after it became clear this was a scientifically important critter.

Email me if you need a PDF copy of the paper.

Kansas Field Season Commences

Well we're heading out again for a quickie recon before my trip to Korea. Hopefully it will be more productive then the last trip, which was a lot of uphill and downhill walking and very little in return. We recovered a partial Xiphactinus skull that I found accidentally last spring, and I found another skull and partial skeleton (so far, it's still going into the outcrop) that we'll be puling out later this spring. Above the first Xiphactinus, I also found and recovered a small turtle, probably Ctenochelys, that even had limb material. This next trip will not have a film crew, so things should go pretty quick!

Disassembling a large jacket

As many of you know, we had to remove our big Daspletosaurus, Pete 3, in 75 different jackets. Jacket RMDRC 06-005-72 was done with a pallet method, weighing in at 4 tons. Paper here on the process.

This week we are making a concerted effort to take that enormous jacket apart, in hopes of keeping it stable as well as recovering a large section of real estate smack dab in the center of the lab. Unfortunately, some bones are going to have to be broken or cut to "unjackstraw" them, but will be reassembled later. The jackstrawed nature of the bones (as well as their fragility) is what made us remove the huge block in the first place, so it's not like it's a huge surprise. Still, it is a lot of work.

BCT is finished!

BCT, our large Daspletosaurus that was excavated from 2001 to 2003 from a very very very hard sandstone in eastern Montana is now finished with prep. Paleo teach Jacob Jett finished the last dorsal vertebra, that was encased in a big ugly block of ironstone concretion. I'm just happy I didn't have to work on that!

Next up is restoration and molding. Stay tuned!

Meet Bonnerichthys!

Just to toot our own horn.

There is a new name for the giant fish formerly known as Protosphyraena gladius. This fish has been known since the 1870s int he Niobrara Chalk, and Cope himself in 1875 had described the pectoral fins of (then) "Portheus" gladius as a "formidable weapon, and could readily be used to split wood in the fossilized condition". We here at the RMDRC do not condone the use of fossil fish fins for wood splitting.

The article covers two specimens, one that we prepared here in 2008, the other that we assisted Mike Everhart in collecting and are still working on.

The work showed that this fish, though related to the cretaceous swordfish analogue Protosphyraena perniciosa, was in fact a planktivorous filter feeder, much like modern whale sharks and manta rays. This type of feeding behavior was not yet reported for animals in the western interior seaway, and is pretty exciting, especially for an animal with a complete lack of sharp pointy teeth.

We are currently working on the first 3d reconstruction made from casts of the specimens in our collection. Keep checking back for progress! Painting at top Copyright Robert Nicholls, used in our paper.