Protosphyraena: Like a Swordfish Made Babies With a Chainsaw

We're back from SVP 2017 in Calgary, which was an awesome opportunity to debut our prototype Protosphyraena (Proto Proto) skeletal reconstruction. I've been involved with this project for 13 years now, very heavily for the past 4 with my various research projects with Drs. Jeff Liston, Kenshu Shimada, Bruce Schumacher and Matt Friedman. We've published a bunch of papers and talks recently, and there's even more on deck. If you're in Tahiti next week, stop by and hear my talk!

Image Copyright Mike Everhart

Loomis' reconstruction attempt

Protosphyraena was a tough nut to crack. The first bits were discovered in the late 1700s in the English chalk and first figured by Gideon Mantell in 1822. It got its name later in the mid 19th Century by Joseph Leidy meaning "early barracuda" due to the flat knife blade shaped teeth. Unfortunately this is what happens when you only have sparse material to work with. Protosphyraena is known now to have a basically worldwide distribution however since the animal has replaced its skeletal bone with cartilage wherever possible, more than isolated bits are extremely difficult to come by. In the Bone Wars of the late 1800s, Cope and Marsh's teams discovered many partial specimens in the Niobrara Chalk of Western Kansas, consisting mostly of isolated pectoral fins and skull bits.

Pectoral of P. perniciosa showing saw-tooth edge

The skull was amazing, with a long rostrum and forward-directed massive protruding teeth. The fins showed some variation, however the ones attributed to Protosphyraena perniciosa reached nearly a meter in length ad were adorned with saw-like serrated front edges. A tail fin was discovered near the turn of the last century and then one the first reconstructions was attempted by Loomis.

Cast and original parts at beginning, apple for scale

Not too shabby based on what they knew. Since the body had such little bone, it was highly unlikely that one would be found, yet the Niobrara as usual was full of surprises. In 2003 Mike Triebold found a partial Protosphyraena skull eroding out of the rocks in western Kansas. The specimen was already missing its rostrum, but a bit of pectoral fin was also visible. He continued excavation and noticed articulated evenly spaced spines, and followed them. They were ribs, hemals and neurals, ans they led to an articulated tail. This was the first "complete" Protosphyraena discovered.

Dig site pic, the specimen is already uncovered and pedestalled

This specimen ended up becoming the "Rosetta Stone" for our reconstruction attempt. Though it was a small example, it gave us tons of information about the body proportions. it kept on giving though, showing the streamer-like pelvic fins and large lobe-shaped "go faster" caudal peduncles.

The "go faster" caudal peduncles

We prepared out several specimens of large Protosphyraena in order to have a decent starting point for the reconstruction. One good skull specimen was partially disarticulated, we scanned the gill basket of a second smaller one and reproduced it out at the proper size on our 3D printing rigs. Our pectoral fin donor specimen was famously covered here as the victim of a poaching attempt in 2011. The original bones were molded and we made multiple copies of the parts so we could cut them up into individual elements. They were later remolded with most of the distortion taken out.

The kid seems bored

Jaws attached

Complete skull exterior

After that, the process was pretty easy! We decided to ignore how bizarre the critter was and just accept that's how these parts fit together, seeing where the reconstruction took us. It tuned out to be stranger than we ever imagined, and a lot bigger too, measuring over 2 meters in length (and flipperspan). We showed it off in Canada and it seemed to be a big hit! Enjoy the photos of the finished mount below.

I'm useful as a scalebar sometimes

Down the hatch!

Front view

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.

Catching a poacher (sorta). Kansas trip #3

Back again after another week of baking my brains out in the chalk in search of long dead marine critters. We were focusing on a strip of outcrops that exposed MU 4 to MU 6 in the lower Niobrara chalk. Found some good stuff too, a nice Pteranodon sternbergi (which will be the focus of another post once prep starts), a partial Xiphactinus audax skull, a small Pachyrhizodus caninus tail, some Martinichthys rostra, and a whole bag of Martinichthys poop! If anyone has any research interest in this poop, let me know, I'd be happy to provide samples.

Pteranodon site

The Pteranodon took up most of our time on till Wednesday, but late that afternoon, Jacob and I finished up and moved on to some outcrops that our crews hadn't explored for a few years. Erosion in the chalk is surprisingly quick, so searching the same spots every 2-4 years is extremely productive. We drove the truck over next to an outcrop and decided to take a quick snack break. While chewing on a small bunch of Red Vines, I look over and notice something blue on the face of the outcrop. "what the hell is that?" I ask Jacob, thinking it is probably just a piece of garbage from the oil rigs in the field.

We go over and investigate, since we had to scout the outcrop anyway. Upon inspection we discover this:

Peek A Boo

A pachychormid fin eroding out with a layer of blue plastic over it. The chalk above the layer was obviously disturbed, and there were small plants growing out of it. Someone tried to poach this fossil!

It's like christmas

We reopened the hole and followed the fossil in. The blue plastic extended quite a ways in. To the end of the fin in fact! Someone excavated the entire thing, then left it! Amazing. We pulled back the plastic and to my surprise it revealed the longest Protosphyraena perniciosa pectoral fin I'd ever seen, 2'8" (82cm) from tip to erosional edge. There were a few fragments in the float and a piece of a radial, but I'm fairly confident we recovered pretty much all of the specimen. Good thing too, we finished up just as another severe thunderstorm was bearing down on us. Also: DON'T STEAL FOSSILS!

Jacketed!

The monster storm a few hours later

Back in the lab our summer intern, Lisa, had the job of preparing the specimen . She did a beautiful job! Now to find an interesting way to display the specimen in the museum.

Big fishie

With nasty pointy fins