Red Zone Road: NSR Highlights

[Mikrogeophagus]

With my limited time in North Texas before my move south, I decided to revisit my favorite sites as opposed to scouting new ones. The NSR is a classic locality, but I had never actually gotten to check out the famed red zone for myself. Yesterday, I made the drive to the fossil park. I was supposed to hunt with a couple others, but it unexpectedly turned into a solo hunt. I won't complain though. The vast river emanates a magical aura that is uniquely felt when you're exploring on your own. The primary goal of the day was to snag a decent specimen of the red zone ammonite, Trachyscaphites spiniger!

 

In an attempt to beat out the stiff hunting competition and high afternoon temps, I arrived to the site in the early hours around seven. Unsurprisingly, I was far from being the first car in the lot. As luck would have it though, none of the people there before me had their sights set on the distant red zone exposures. It's a long and taxing trip that only so many people (the crazy ones) are willing to undertake. After crossing under the 2990 bridge, I took in the view and tried to visualize where the destination might be. It was quite daunting, but the journey of a thousand miles begins with a single step.

 

Red Zone Road

 

It was gonna take a lot of walking to reach the mouths of the red zone creeks, so I tried to keep the gravel hunting minimal along the way. Nevertheless, my eyes were still scanning the ground around me and the vigilance steadily began to pay off. After a few Enchodus fangs and a Carcharias holmdelensis tooth, I came across the first prize of the day. Cemented together in red zone matrix was a mass of turtle shell that I had never before seen a similar specimen of. It has some good weight to it and cool three dimensional character. I don't know enough to identify it to a genus assuming that's even possible. I believe Archelon and Ctenochelys are known from the NSR as well as other genera I'm sure.

 

Articulated turtle shell fragments in red zone matrix

 

Some time later, I came across an interesting bone fragment that I don't have much of a clue about. The texture seems like fish. It has pronounced ridges running longitudinally and a U-shaped spongy cross section. I held onto it in case it might be something cool.

 

Mystery bone

 

Here and there I came across various red zone ammonite chunks to whet my appetite. None of them were keepers in part because I had high hopes for what lay ahead. Maintaining my steady pace brought me to the mouth of the first creek I had circled. Yesterday's 25 foot rise was still draining and the sound of rushing water filled the air with occasional thuds from falling shales. In the high cliffs I could see a distinct red band of matrix slicing through the grey shales. Tracing it with my eyes, I followed the line upstream until it was within reach. It was absolutely filled with phosphate chunks and nacre-covered Baculites. After a short time, I locked onto a Trachyschaphites that was just poking out. Excitedly, I threw out my tools and began excavating. My enthusiasm was quickly washed away as I realized the chunk sticking out was just a chunk. This sequence of events repeated itself along the entirety of the creek and before I knew it, I was exiting with a bag of assorted Trachyscaphites pieces. The only interesting things to show were a beat up red zone mosasaur vert and some snails.

 

Red zone mosasaur vert

 

Gastropods from the red zone

 

Now the temps had crossed into the 90s and beads of sweat were covering my face. Wanting to take a break from the red zone, I began a thorough search through the massive gravel bar outside the creek. It took awhile to warm up my hunting goggles, but eventually I spotted the first keeper of the bar: A big ole worn mosasaur tooth. Sadly, it was sliced in half and had chunks busted out of it. Not too long after, though, I got it a smaller, much more complete friend.

 

Likely Tylosaurus proriger

 

After these mosasaur teeth, I scored what I like to call a "pseudo-mosasaur" or its other name, Pachyrhizodus. It was pretty easy to spot the difference since a little bit of bone was attached beneath the crown. Still a cool little fish tooth.

 

Pachyrhizodus 

 

I'm not very good at spotting artifacts despite having spent many hours in the creeks of Austin. Now and again though, I manage to blindly stumble my way into a killer point or two. Wedged into the sand beneath the receding waters, was the unmistakable base of a Gary. Haven't found one of these before, so I was pretty happy to add this NSR classic to my collection.

 

Gary in situ

 

Gary point

 

The last and most interesting find of the bar was a huge chunk of Xiphactinus jaw! It seems to match up exactly with the very distal end of the lower jaw. Within two matrix-filled tooth sockets are a couple of emerging teeth.

 

Distal end of a Xiphactinus lower jaw with a couple of teeth.

 

Finally, it was time to set my sights on the creek across the river. To my knowledge it doesn't have a name as it is quite small. The disappointment of my previous red zone expedition set my hopes low. Although the tree cover was nice, with it came swarms of mosquitos and some sort of biting fly. I spent most of my walk through it flailing my arms trying not to become a walking buffet. The red zone was much better exposed and I quickly spotted a couple of Squalicorax that sadly weren't keepers. There were many Trachyscaphites fragments to waste my time, but at long last I ran into exactly what I was looking for! With careful swings, I worked the heteromorph out of the shale and quickly stored it safely in its own private Ziploc bag. With the primary objective met, it was time to quickly evacuate the mosquito hellhole and return to the safety of the sweltering sun.

 

Trachyscaphites spiniger heteromorph (my favorite ammonite). There is a significant crack that hasn't completely split. Hopefully the b72 will hold.

 

It was about 4 pm and I was close to my limit. There was another spot further ahead known for arrowheads that I wanted to see, but I was saving that for the people I was intending to meet (no cell service so I didn't know plans had changed). It became apparent no one was coming, so I gathered my bucket and pack for the long trek home. The adrenaline of fossil hunting had definitely carried me through the day. The river now seemed endless and every step of foot sucking mud taxed me more and more. After retracing my route at home, it seems I river walked at least 5 miles! As I crawled into my blistering hot car, I told myself one red zone hunt was enough for the rest of my life. But after a good night's rest and cataloguing my finds, I'm ready to go again . I guess we'll see how I feel next summer.

 

 

Thanks for reading!

[Ludwigia]

Thanks for the report. Just out of curiosity, how far did you walk in the end to reach your coveted Trachyscaphites?

[grandpa]

Great report.  Thanks for taking us along.  Great finds as well.

[Andúril Flame of the West]

Very enjoyable report and some wonderful finds. I felt like I was right there with you slogging through the mosquito-ridden swamp.

[Mikrogeophagus]

9 hours ago, Ludwigia said:

Just out of curiosity, how far did you walk in the end to reach your coveted Trachyscaphites

It took about 4 miles to find it and then an extra mile to walk all the way back to the bridge!

[Ludwigia]

3 hours ago, EPIKLULSXDDDDD said:

It took about 4 miles to find it and then an extra mile to walk all the way back to the bridge!

 

Nice to hear that you got your excercise in for the day

[Jared C]

20 hours ago, EPIKLULSXDDDDD said:

After these mosasaur teeth, I scored what I like to call a "pseudo-mosasaur" or its other name, Pachyrhizodus. It was pretty easy to spot the difference since a little bit of bone was attached beneath the crown. Still a cool little fish tooth.

 

 

 

What made you come to the conclusion of pachyrhizodus?

[Mikrogeophagus]

43 minutes ago, Jared C said:

What made you come to the conclusion of pachyrhizodus?

 

Around the circumference of the base of the crown, are thin bits of bone. It seems I misremembered something you told me not long ago about fish teeth having thin walls of enamel sometimes preserved because of their tooth replacement mechanisms. In my head I remembered it as thin bone preserving, so it seems I jumped the gun. Looking at it now, it does seem quite large (1.6 cm) for Pachyrhizodus...

 

I wouldn't be too sad if this turned out to be a mosasaur tooth though.

[Jared C]

1 hour ago, EPIKLULSXDDDDD said:

 

Around the circumference of the base of the crown, are thin bits of bone. It seems I misremembered something you told me not long ago about fish teeth having thin walls of enamel sometimes preserved because of their tooth replacement mechanisms. In my head I remembered it as thin bone preserving, so it seems I jumped the gun. Looking at it now, it does seem quite large (1.6 cm) for Pachyrhizodus...

 

I wouldn't be too sad if this turned out to be a mosasaur tooth though.

seeing views of the bottom from a few angles might be helpful  

I agree it's too large for Pachyrhizodus

 

That thin wall of enamel you have in mind is where the tooth in some fish is ankylosed to the bone. The replacement mechanism of teeth in fish is usually like that of stacked cups, allowing the ankylosed enamel to push up neatly and follow the attached tooth when shed. This enamel is extremely delicate though, and rarely preserves well.

 

For an example of ankylosed enamel in a fish, here's a photo of such enamel on my Hadrodus specimen.