What's the Bag Limit on Xiphactinus?

October has a lot of opportunities for hunting big game such as deer and elk. Some people use muzzleloader firearms or bows and arrows. I prefer to use my trusty walking shovel, Winona.

Fishing for the biggest toothiest one out there

This October I led a small field crew out to the Niobrara Chalk of Western Kansas, squeezing a week of scouting in between seminars and the Society of Vertebrate Paleontology meeting in Minneapolis. Due to injury, this was my first time out on the rocks since August. The Kansas chalk is full of some amazing fossils like Pteranodon, Tylosaurus, and my personal favorite, Martinichthys. It also has Xiphactinus.

Finding a piece of Bonnerichthys while wearing a Bonnerichthys shirt

By Wednesday morning of the trip, we had found a few cool specimens like a pathological tail fin from an ichthyodectid fish, but nothing large or truly impressive. As my crew packed up some of their gear at the truck, I struck out for a distant outcrop that I could see the distinctive Marker Unit 5 layer (home to Martinichthys). Less than half of the way there, I looked down and froze.

Fish face as found, curatorial hand for scale

Eroding out of the small exposure of chalk is the perfectly articulated face and pectoral fin of a moderate sized Xiphactinus. The amazing thing is the up side of the fossil was all still articulated. Usually when the animal decays on the seafloor, the top side gets stirred around a bit by scavengers. The bottom part, pressed into the seafloor ooze, is usually even better.

Evan and Jordan opening the site to see what's there

Before touching it I grabbed the team. They were from our 3D department and were getting some well deserved away-from-screen time. This past year I worked with them on so many excellent dinosaur, mosasaur and crocodilian reconstructions that some fresh air and exercise seemed like a great respite. And what better way to get fresh air and exercise than with digging up a giant fish? I told them I found another Xiphactinus and they only groaned a little. When they got to the untouched site, I think they got a little excited. It's not every day you have the chance to work on a beautiful fossil like this one.

Undercutting process begins

When you're big and dead and bloated floating at the surface of the Western Interior Seaway, you make a really nice meal for all kinds of predators in the late Cretaceous. After a little excavation (the site had maybe 3 inches of overburden on it), we determined that all that remained of this fish was the disembodied head, fins, and a few vertebrae. The rest of the fish was long ago consumed by some lucky shark I think. That made our jacketing job so much easier, as this was originally a 12 foot long fish.

The jacket is finished!

I was very nervous about the flip of this large jacket in very loose and friable chalk. I broke out every trick I could think of to ensure success but the lift and flip was extremely stressful. Luckily, 27 years of experience paid off and the flip went perfectly! We lightened the jacket by removing a little of the extra chalk, then loaded it into the back of the field truck to bring back to Colorado. The naming scheme this year is due to a song I had stuck in my head, so they all flow from a stream of consciousness rant during the song "A Shogun Named Marcus" by the band Clutch. This being the 4th good fish I found this year, it gets the name "Spitfire", which I think suits it just fine.

I managed to get 2.5 out of the 3 of us in this shot. Successful flip!

All in all, it was a very successful expedition to the Niobrara. No pterosaurs or giant lizards, but a big fish head and another specimen worthy of publication is still a good haul. Stay tuned for more updates as we get to preparing Spitfire's fish face back in the lab. 

Ashley: The cannibal Xiphactinus

 If you're following me on the twitters I'm sure you all know about my absolute and undying love for the giant ugly predatory fish from Kansas, Xiphactinus audax. We spend a lot of time in normal years in Kansas during the spring and fall (when the weather and bugs aren't too miserable) and we tend to find a good number of at least partial skeletons, some exceeding 18 feet in length.

Random Xiphactinus verts in the wild

It's easy to think of them as just another boring fossil, as if they were the hadrosaurs of the ocean, but every once in a while something about them makes them interesting.Sometimes because they are found inside something interesting, other times because something interesting is found in them.

Xiphactinus as stomach contents of a large shark, Cretoxyrhina
Photo taken at University of Kansas Natural History Museum

Xiphactinus is well know for its gluttony. The famous "Fish Within a Fish" at the Sternberg Museum of Natural History, where a 13 foot long Xiphactinus semi-successfully ingested a nearly 6 foot long Gillicus is a prime example of this. I claim it to be semi-successful as the Gillicus is completely articulated and not digested, indicating that trying to swallow this meal likely killed the Xiphactinus. Other times smaller remains of a fishy meal in the body cavity of a Xiphactinus are found, we see this in a little less than half of our specimens.

Photo courtesy of Mike Everhart www.oceansofkansas.com

Fast forward to the spring of 2018. I was scouting the lower Niobrara Chalk in Gove County, Kansas. The chalk is defined stratigraphically by 23 distinctive easily traced (usually) bentonite layers laid out by Hattin in his 1982 work. These outcrops were around Hattin's Marker Unit 6, so the upper limit of where I could possibly find my dream fish , an articulated specimen of the ram-snouted Martinichthys ziphoides. No luck on that front however I did find this fine pile of bone eroding out, seemingly face-first. A small pile of bones is always a good sign!

The bones are the kinda grey things on the yellow chalk

Unfortunately it looked like it was headed into the base of a big cliff. After initial evaluation, we decided to GPS and cover up the site to protect it until we could come back at a later date. That date came the next spring.After a long morning of removing overbruden, we were relieved to see the fish had actually folded in half back on itself about 4 feet from the erosional edge and the balk half pointed back out that direction. We didn't have a tail fin, but we also didn't have to move a mountain of rock chasing this Xiphactinus either. I gave it the nickname "Ashley" after one of my trivia teammates (remember when we could go to bars and do that? Wear a mask and maybe we can soon).

Can you see the digsite?

One of the strange things we noticed while exposing the bones in the field was a large bulky bone near the belly. It looked like a cliethrum, one of the bones that the pectoral fin hangs off of. The skeleton itself was mildly disarticulated in parts, and any Xiphactinus will have 2 of them, so maybe this was just a bit of Ashley that was pulled off the carcass when scavengers like the shark Squalicorax came to strip off all the flesh.

Typical Kansas fish dig

Preparation showed the skeleton was in much better condition than we had imagines, with decent articulation and a beautiful pelvic fin. It also showed both cliethra that were supposed to be present on a Xiphactinus wee in fact there in place. So what does that mean with our now THIRD cliethrum?

2 very nice looking jackets all cleaned up

One way to be sure is to prepare it as well. Free from all of its matrix two things were readily apparent: One: the acid-etched texture of the surface of the bone meaning it was stomach contents and Two: based on the shape, it also belonged to Xiphactinus.

The smoking gun, so to speak. Acid-etched Xiphactinus cliethrum

With that shocking knowledge in hand with al of the bad things Xiphactinus could be (common, boring ugly, a lot of work to dig up and prepare) we can also add cannibalism to that ever growing list.

First Kansas Trip in the Bag - 2017

For the first time in a few years, we've been able to hit the Niobrara outcrops in the spring! Holy crap was it cold. The last day out, I don't think it got above 50 degrees, not that the 40mph winds would make it feel any warmer. Perfectly miserable. And just like clockwork, on our last day, as the sun was setting behind a large row of thunderstorms on the horizon, we found the best skeleton of the trip! The rest of the time was staring at blank ground finding fossil poop.

Look at this swirly poop!

I entertained myself by finding a "nice" Xiphactinus tail. I was instructing a new hire on how to actually find fossils in pretty bleak badlands when I saw just a small fragment of tail fin coming out of the rock. I'm happy I found this one as since we have SO MANY Xiphactinus specimens in storage, we've implemented a "one in, one out" policy on these fish and I've somewhat jokingly insinuated firing anyone that finds another of these darn fish. Our newbies were safe.

Well, there's a fish tail

Jesse using a chainsaw to trench around the fossil

When you find weathered out fish tail chunks, you have to chase them in (even if they're "just" a Xiphactinus). Sometimes the rest of the tail is there. Sometimes there's the rest of a 15 foot long fish attached to it. Sometimes it just ends. In this case, we found a perfect lower lobe of the fin, but no body. As far as we were from the truck, I'm happy we didn't have to make a huge jacket, since those are heavy and I'm getting lazy in my old age.

Trenching complete, curatorial boot for scale

Jacketing complete and ready to flip, other curatorial boot for scale

Popping it out and prepping it was also quick. Measuring the vertebrae we found it's the exact same size to complete another Xiphactinus specimen we excavated 3 years ago (which just happened to be missing the tail). This will help us out tremendously when we panel mount the animal in the near future.

Not too shabby!

Other stuff was less plentiful on this first trip, but we were lucky enough to find parts of 3 sea turtles, which is always really nice.

Jesse and grace entrusted with power tools to get to a turtle

And of course at the very last minute, Jesse stumbled on a pretty complete Clidastes skull in an outcrop near where we discovered our gigantic 17 foot Xiphactinus specimen 20 years ago. We worked very hard to excavate the specimen with daylight fading and weather bearing down on us.

Jesse and grace getting Clidastes block ready for jacketing

The specimen was safely loaded in the truck by headlight, which also made for a really interesting drive through farm fields in the dark at the end of a 14 hour day. Prep is going on right now, so stay tuned to see how this cute little mosasaur turns out!

The Accidental Ichthyornis

Field identifications are problematic.

In mid October of this year the weather in Kansas was still warm enough to extend our dig season. That trip was pretty successful, finding a back half of a Protosphyraena and several small fish. Early on, Mike even thought he found another Pteranodon leg.

The drive to the site is a lot tougher when you can't see landmarks

We came out early in the morning. Man was it foggy. The entire day was supposed to be dedicated to finishing up excavation at several small sites. Since the "Pteranodon leg" site was so small, Mike and Jacob spearheaded the excavation there, while I wandered off to collect a Cimolichthys head and isolated Ichthyodectes site.

Several bones coming out at the site as discovered. Definitely not fish.

The "Pteranodon leg" showed some promising chunks of bone coming out, however inspection as they got down to the bone layer showed not a whole lot was there. Not like the large bones we were hoping to find for a Pterosaur.

That's a big hole for such a little block

Not a huge worry though, we perimeter the sites and very rarely expose the bone in the field, we will just find out what the "Pteranodon leg" looks like when we get back to the lab.

Jacob jackets and despairs as I tell him we have to go dig up another fish

Looking back at the video, just as Jacob began jacketing the specimen, I show up back at the site proudly announcing the discovery of the "Nia" Xiphactinus site that I blogged about last time. We all decided to drive over to the big fish and start work as the jacket cured. We were so stoked about the big fish that it was about a month later when we finally asked ourselves "Hey! Where did that jacket go?"

Turns out, we left it sitting there in the field, right next to a regularly visited oil well. Whoops! Over Christmas, Mike returned to the site to see if someone had poached it. Nope, the jacket was still exactly where we had left it. I guess you can say we got dang lucky. Let's never do that again.

Mike pulled it out and brought it back to the lab, where it sat for a week as I let it dry out (dry chalk behaves better than wet stuff when prepping, especially with small fossils). That's when the Eureka Moment happened: prepping down on the "Pteranodon leg" things weren't looking right. I immediately switched to my microscope, pin vise and very low pressure air abrasion (about 3psi with sodium bicarbonate blast media). My suspicions on the specimen's identity were confirmed when I found teeth. Pteranodon doesn't have teeth, but there's one small thing in the chalk with reptile-textured bone that does have it: a bird! Not only was it a bird, but the only complete articulated skull of Ichthyornis, who had been found only in fairly incomplete form since Marsh's days in the 1870s. This accidental and overlooked jacket suddenly turned into one of the rarest finds in the entire 160 year history of fossil hunting in the Niobrara.

Bird teeth, just a few milimeters long

Stay tuned for project updates as we work on this spectacular fossil.

Fall Xiphactinus Surprise

Let's go to Kansas they said. We'll find some marine reptiles they said. It'll be fun they said. Boy, were they wrong!

October is tarantula migration season

Doing fieldwork in Kansas at the end of October is pretty rare for us, but we lucked out with the weather and spent a few days hitting outcrops we hadn't been on in a few years. It's important for them to go through an erosive "refresh cycle" so that we can find new stuff on the same ground. In just the first day we found the remains of a partial Pteranodon sternbergi and a few cool small fish. Mike and Jacob were working on excavating Pteranodon #6 of the year and I was finishing up jacketing a nice Ichthyodectes ctenodon specimen and had a little time to kill, so I wandered off to the south a little bit to scout for some cool treasures. I had been over the area just a few yeas before, so I was expecting something small.

The chin

Curator at digsite for scale

That's when I accidentally found the biggest fish of my career laying on its left side. I nicknamed it "Nia". She's a Xiphactinus audax over 17 feet long when whole, with pectoral fins each 2 feet long.

There was a serious lack of overburden at first

Luckily overburden wasn't a big problem at first, with an average of about 4 inches (100mm) of chalk over the specimen. Digging in though, the articulated strand of ribs, spines and vertebrae were pointed straight into the outcrop wall.

Expanding the digsite

The Niobrara sea was chock full of predators ready and willing to scavenge a dead animal, and they didn't pay Nia any respect either. We discovered a half dozen shed Squalicorax falcatus teeth in the head area, lost while taking chunks of meat off the carcass. Unfortunately (or mercifully, depending on how you see it) the body was bitten off about 5 feet from the start of the dig.

Jacob driving a chalk-splitting chisel under the big jacket

How the specimen flipped in the field

Jacketing was a bit tough and we anticipated some problems with a huge flat jacket in soft weathered chalk. We feared a collapse (like that one other Xiphactinus I found a few years back that I nicknamed "Bea Arthur") so we did everything possible to try to get the specimen out safely. It still fell out, but to our amazement, almost all the bones remained in place in the jacket!

Show prepped main jacket

The rest of the jaws will go back in place later

Show prepping took a long time because of how soft the bones were. I got it into the "pretty enough" stage and now Nia is in storage, waiting for her turn to be turned into a spectacular panel mount.

Our Xiphactinus dig featured on River Monsters: backstory

I really hope everyone got a chance to see the River Monsters season finale. Here's a teaser of Jeremy Wade Sharing a bit of what he had learned with us in the field digging up a Xiphactinus audax skeleton.

One of the things he alludes to has a funny backstory. When we first arrived at the site, the film crew's rental minivans couldn't get near where all the equipment needed to be. Not a huge problem, we transferred it to the bed of the bosses truck and away went the gear and most of the crew. I had been riding in vehicles way too much already that morning and decided I'd walk the easy 1/4 mile or so left to the site. Jeremy, the director and an assistant decided this was a good idea as well, so I was able to show them some things in the chalk on the way up. Mostly clams. Lots and lots of clams.

The site is on the opposite side of the butte in the background

Arriving near the digsite site, literally within 4 feet of where the boss parked the truck, while talking to Jeremy about how you have to be in the right place at the right time to find a specimen, I look down and see the face of a newly eroding Xiphactinus specimen poking out of the rock. I COULD NOT HAVE PLANNED IT BETTER. It's really not all that great, but our guests had never seen the discovery of a fossil before, and they seemed pretty thrilled about it. Happy I could oblige.

Can you see it? It's a beauty!

Back in the lab the next day we worked hard to begin the prep on the Xiphactinus specimen RMDRC 14-012, which we nicknamed "Jeremy". Unfortunately, all of that seems to have ended up on the cutting room floor.

Just a few people watching over my shoulder as I prep

Nevertheless, we went ahead and finished prep on "Jeremy". Not the prettiest one, and for the life of me I can't figure out how the face was nicely articulated but the entire braincase was spun off and away. Them's the breaks I guess. As for working with the River Monsters crew again? Name the time and place, they were superb.

I've seen worse

Sclerotics in place still!

See us on River Monsters this Monday!

I can't reveal too much until the air date, but I can now share that you'll be able to see Jacob, Mike and myself on the season finale episode of "River Monsters" starring Jeremy Wade!

Looking busy in the glory of the Blue Shirt

Jeremy came out to the field with us recently, then visited the museum, film crew in tow, to experience a fish dig in Kansas and what we do with the fossils once they return to the lab. It was a busy but fun couple of days with him and the crew from Icon Films. Hopefully what airs on Animal Planet features my good side!

No love for Ichthyodectes?

It seems like nearly every year a new book, film, or television program comes out featuring the long-dead seaway that covered most of the central part of North America back in the late Cretaceous. Invariably they have cameos featuring Xiphactinus, Cretoxyrhina, Protosphyraena, and even the "bait fish" Gillicus and Enchodus. They have mosasaurs, pterosaurs and even sea turtles. If you didn't follow the science closely, you'd understandably figure that's about all that lived in that shallow sea.

Our cast specimen restored in all its 3d glory

Truth be told, there were probably a few hundred types of fish in that seaway. Dr. Kenshu Shimada made a decent attempt to catalog all of them a few years ago, but like all good science on the Niobrara, it was getting out of date almost as soon as it was published. It's really amazing that 120 years after collecting work began in Western Kansas, new critters are still being found. I'm not going to go into details on them (I'll save them for other blog posts) and instead focus on this fish that is criminally underrepresented in the literature and online.

RMDRC 11-018, a massive 9 foot Ichthyodectes

If it's Wikipedia entry were any indication of its importance, what does the text containing a whopping total of 89 words tell you? That's right, 89 whole words, some of which are even talking about other related fish. Lame.

Some of the teeth of RMDRC 11-018. Yikes

Ichthyodectes, a fish with moderately terrifying teeth and with a body length approaching 9 feet, it's not cheered on much. Sure it's pretty common in the Niobrara, but it's also basically a pocket Xiphactinus (see, using the Wikipedia trick of talking about it's cooler cousin to gin up some interest). An average scouting season for us will find 5 or so specimens identified through cranial material. Probably more, but postcranially all ichthyodectids of about the same size pretty much look identical.

RMDRC 14-027, excavated with a film crew, watch for it soon on TV!

Perhaps a big reason as to why Ichthyodectes gets so little love is that there are so few specimens on display in museums, even fewer ones that look, um, not silly. Perhaps we need more museums to decide that decent specimens of lesser known fossil fish of the Niobrara are just as important for display as mosasaurs or sharks or Xiphactinus. Maybe I'm just asking for too much. In any case, I've pretty much doubled the amount of useful Ichthyodectes pics on the interwebs, so I'll count it as a win.

A little photographic update: Xiphactinus Mildred

Jacob and Lisa keep plugging along on the gigantic mount of the huge 18 1/2 foot long Xiphactinus audax "Mildred". Basic assembly except for the fins are now finished, hopefully soon we will be able to rotate the mount to its upright position, working on a 5 foot high table is not exactly fun.