3 New Spots; 30 Days; 300 Million Combined Years of Mosasaurs, Sharks, and Mysteries to Discover

[Mikrogeophagus]

Apologies for the dramatic title. I thought it sounded cool and stuck with it even though 90 + 80 + 80 is only 250 . Anyways...

 

This past 30 days, I decided to make it a point to check out some new spots. I won't be living in Austin soon, so I thought it would be good to branch out and scout some new locations with potential. I've found lots of creek-worn mosasaur bits and pieces over the past year. I'm ready to find things in situ, and, one day, something articulated. It's a tall order, I know, but I feel like it's the next step and really the ultimate goal I've always had. So, the first step towards this objective was to find locations and, of course, take a look. This is what I saw!

 

 

Location 1. Austin Chalk:

 

In my usual Ozan stomping grounds, I've come across a variety of fossils ranging from the Eagle Ford to the Ozan itself. Included, was an assortment of spectacular Austin Chalk invertebrates along with the occasional and highly sought-after mosasaur vertebra. They can be readily distinguished from their Ozan counterparts by their yellow-orange preservation and lack of pyritic elements. Honestly, I come across them just as commonly as I do Ozan verts, so I took this to be a sign that the Austin Chalk could be a good bet. In Austin, it's a pretty wide formation with lots of members to look into. I did some research and found a place with some potential.

 

When I arrived, it was a hot afternoon. I picked up my backpack and swapped my school notes out for a rock hammer and a couple of icy bottled waters. Walking down a little trail, I came across the first large exposure of Austin Chalk in what I believe to be the Dessau member. Literally within the first minute, I had to take a double-take at a white glint on the ground. "Surely there couldn't already be a shark tooth," I thought to myself as I kneeled for a closer inspection. Sure enough, it wasn't just a shiny piece of shell; it was indeed the enamel to a bleached tooth from the king shark of the Late Cretaceous seas, the infamous Cretoxyrhina mantelli! Thankfully, it popped out in one piece.

 

A recreation of the tooth in situ and after extraction.

 

I poked around the rest of the surrounding exposure. There were a couple of mangled echinoid bits and gastropods, but not much else, so I continued on to search the main creek. Unfortunately, the only apparent path forward was along a narrow and steeply banked feeder stream. Many of you will know that navigating through these can be a real pain. The brush was densely packed and smelly stagnant water had to be avoided with every step. There were thorny vines dangling from each limb and I was constantly tasked with picking off the burrs that snagged onto my clothing and in my hair. Last year, I was in a similar situation when I was suddenly attacked by a hive of wasps (don't worry, I managed to avoid getting stung too much). It's a fun story to tell friends now, but I must admit that the thought always crawls back into my mind when I am in a position that's a bit difficult to get out of in a hurry. Anyways, after about twenty minutes, I took the final hop over a fallen tree to get to the main creek. It was nice to breathe in the fresh, open air as I sat my backpack down and took a rest, of course, with my eyes perusing along the limestone bed. After the brief sit-down, I began to notice the beauty of the area I was in. The air was filled with the drip-drop of water leaking from the fern-covered bank and the reflection of the greenery was simply mesmerizing. I couldn't help but snap a quick photo. 

 

 

A beautiful, hidden place away from the city. Though, not too far... there's a shopping cart wedged in the gravel just out of frame. 

 

In terms of fossils, this place was loaded. Just about everywhere I stepped, I was standing over piles of clams and oysters along with the occasional baculites segment. I didn't bother taking any of these with me, however, as I have plenty already. I noticed there was a decent amount of chert as well, so artifacts were on my radar when I came across a preform. A little farther down the creek, I found a nice ammonite fragment. I didn't intend on keeping it, but sometimes it's nice to have something to hold so I took it along with me.

 

By now, much of the afternoon had come and went. It was about time I turned around and faced the prospect of navigating my way through the dreaded feeder creek in reverse. As I was coming to a stop, I saw a girl walking along the slanted banks of the creek who almost certainly did not enter the way I did. I tried my best to get her attention without spooking her (keep in mind I look and smell like a swamp monster at the moment). She was nice enough to come close to the limestone ledge and introduce herself as I trudged my way through knee deep waters towards dry land. Turns out, she's a local who often hikes by the creek. We chatted for some time and I ended up giving her the preform and ammonite fragment, hopefully inspiring a future hobbyist. After explaining the situation I was in, she laughed and pointed out a trail that led back to the road. When I climbed out and exited the trail sore and tired, I kicked myself. My car was right in front of me. I could have taken this path from the beginning, but instead I took the road never traveled and boy did it make all the difference.

 

 

Location 2. Ozan Formation:

 

Although many of the mosasaur verts I come across are from the Austin Chalk, a significant portion are still from the good ole Ozan. With that in mind, I took a trip to a creek I usually don't hunt that had a decently-sized exposure. Something in a book tipped me off to this particular site, so I had high hopes. The trip from the road to the waterway wasn't as troublesome as the feeder creek from the week before, but it was still a challenge. I worked my way along the dirt bank to a place I could safely enter the waters when I saw what I was more so wary of. Across the lazy stream was a tent set up along a slope with a clothesline and shopping carts around it. On the initial drive to this spot, I did take notice of the pronounced homeless presence in the area. From the cover of the trees, I took a moment to scope out the tent and the surrounding area. The last thing I wanted was to have an unexpected encounter in a secluded place like this. Luckily, it seemed nobody was home, so I entered the creek, though making sure to have my rock hammer visibly in hand.

 

When I approached the first gravel bar, I was greeted with tons of broken down blocks of Ozan shale and various Austin Chalk fossils. Curious, I started splitting the blocks open to see what the area had to offer. Each one was filled with heart urchin spines and plates! Most were fragmented and all were extremely fragile. Still, I took this to be a good sign. After hours of splitting the loose slabs, I finally found a complete irregular urchin. It's a definite upgrade from the half of one I had found a while back in the Ozan (though that one did have a nice red color).

 

A compressed heart urchin. Looks to be Pliotoxaster/Hemiaster? It may appear round, but it is totally flat!

 

The slab splitting continued with some compressed ammonites and enchodus teeth, but not much more, so it was time to move on to the main event. As I walked the rest of the gravel bar, however, I was forced to once again stop in my tracks. Lying in the mud right in front of me was, by far, the largest mosasaur vertebra I had ever seen in person. It had the preservation of what I assume to be Austin Chalk (of course as soon as I return to the Ozan). The underside of the vert was badly weathered, but it was, nevertheless, far heavier than any others in my collection. Plus, I only need one decent side to show in my picture .

 

Gargantuan mosasaur vertebra. I wonder how long the whole lizard was.

 

Welp, there's really no better motivator than something like that, so I took the short walk to the main exposure. A large expanse of creek bed was Ozan shale ripe for the picking. I got straight to working chiseling out every strange thing just poking out of the ground. Most of them were only oddly shaped pyritic accumulations, I'm guessing originally bivalves and poop. Now and then I would come across a Hamulus squamosus worm tube or piece of fish bone. The bed was a little difficult to see as the lack of recent rain meant that the detritus and algae had yet to be washed away. I didn't find much in the water. Thankfully, the dry parts of the bed were easy to probe. Eventually, I came upon something unmistakably bony. Before I could stop myself to snap a photo, I was already digging. It popped out easily and was instantly apparent of being mosasaur, the very thing I was seeking most. Frantically searching for a continuation of the vertebral column, I spotted what I thought was the head of the next vertebra behind. In my mind, I could see it all right in front of me. The ultimate prize was right there! Just some minor excavating and I'll have done it! Perhaps in theme with fool's gold, I was fooled by the imprint of the very fossil I had just pulled out . I was bummed out for a second, until I had time to realize that this was my first ever mosasaur vert found in situ! 

 

Out popped my first in situ mosasaur vert! Cleaned up, it is a real beauty. The color of the cuboidal pyrite outgrowths looks amazing when moved under the light. "Fool's gold" is a real disservice as far as names go.

 

And with that, the sun was already starting to set. 

 

The finds of the day. 2 mosies, a flattened echinoid, a Hamulus squamosus tube,  an Austin Chalk ammonite, and an Austin Chalk Exogyra tigrina.

 

 

Location 3. Ozan Formation:

 

After crossing such a major milestone, I had no choice but to head out for the Ozan again once a brief rain had passed. This new location was similar to number 2 in that it was a large expanse of Ozan creek bed. Unfortunately, the route to reach it from the road was a treacherous one. I didn't intend on swimming across a sudden deepening of the creek waters, so I had to search along the steep banks for ways to traverse the barrier. There was somewhat of a flattened trail along a slope with various obstacles that seemed the most doable to me. For the most part, I side-stepped my way across, hugging the dirt and tree limbs to avoid losing balance or putting too much weight on the unstable ground. Now and then, I'd have to cross through a bush that would replenish the population of burrs covering every part of me. By that point, I couldn't have complained too much as things were going relatively smoothly. That is until I made one misstep and had to quickly catch myself by snagging an exposed tree root. Regaining my composure, I heard the rustling and sliding of a plastic bag followed by a loud splash of water from underneath my feet. I usually carry my dirty pair of tennis shoes in a plastic bag since I swap between them and water shoes on my excursions. Now they were just a white shimmer far beyond reach.

 

I hopped off the bank and landed on firm ground. Most of the bed was readily exposed to the air. There was a high density of deer and raccoon tracks. I was entertained most by the shale claw marks I saw at the bottom of shallow pools that I interpreted to be raccoons taking a refreshing swim. From way up the creek, I even caught a glimpse of a coyote jumping from out of the foliage. He sniffed around a bit before noticing me and darted off the other way. I settled down to catch my breath and inspected broken bits of Ozan shale nearby. Pretty soon I spotted the first regular echinoid I've seen in the Ozan. Unfortunately, it was too fragile and didn't survive the journey home.

 

A regular echinoid and a mess of urchin spines surrounding. This portion of the Ozan is rich in echinoid material, though heavily compressed and often very fragile. Denture clams are the other most common find of which fragments can also be seen here.

 

After some rehydration, I got up to start looking for bone. It took some time, but I eventually found a peculiar specimen sticking out of the shallows. It was too suspect to ignore, so I began excavating.

 

Spongey thing as originally found.

 

I was hoping it would be a rib or something, but it just didn't look right. The pores of the cancellous bone were much larger than what I was familiar with for reptiles and the thing didn't seem like fish at all. Typical for fossils in this layer, there was pyrite all over. However, there was an additional mineral I hadn't encountered before. Encrusting the entirety of the underside were selenite(?) crystals in prismatic shapes. As I dug deeper and deeper, the form continued on.

 

The spongey thing was long and had curvature. There was another short one layered just underneath it intersecting close to the hammer. If it's vertebrate, I have no idea what bone it would be. I suspect it's invertebrate in nature.

 

Revealing more of it showed that a separate, shorter piece was present just underneath. Both structures were flattened, fragile, and had to be removed in chunks. From what I could tell, their spongey structure remained consistent across the entirety of their lengths. Once extracted, I searched the surrounding space, but found no sign of continuation.

 

Post extraction

 

I was completely stumped by what I had found. All I could think was spongey, pores, spongey, pores. I am embarrassed to admit it took me way too long to cut off the "y" and realize that it's likely a sponge. Pore bearing (porifera) is about as accurate as you can get when describing it. So, I settled with that as my final guess for what this mystery structure could be. Though, this is still up for debate, so let me know if there are any opposing opinions.

 

 

From there, I took a couple of paces before stumbling upon the next thing of interest. It was a robust black protrusion with some apparent symmetry. Okay, if the last thing was pseudo-bone, surely this had to be the real thing. As per usual, there was pyritic encrusting on it. From how it was positioned, it was hard to say how long it could be - if there was much more to try and dig out. I got to chiseling and it popped right out within the first few swings. Instantly, I knew I had once again fallen for some pseudo-bone. That being said, it was the first time I had found carbonized wood in the Ozan. I don't usually keep fossil wood, but this guy is interesting enough to warrant it.

 

A pyritized deposit of coal, pretending to be a mosasaur rostral.

 

The fossil wood with a pyritized denture clam and Serratolamna(?) tooth on top. A piece of an artifact and irregular urchin on top. The clam on the right is a cool optical illusion. It's only 3/4 of an inch tall.

 

Here and there I made some other nice smaller finds. A fragment of an artifact, some shark teeth, and an even better flattened irregular urchin to name a few. Though, I had spent a lot of the recent weeks hammering away at things in creeks, so I thought it would be best to call it early and head home to have a nice meal and reflect on my prizes. No articulated mosasaur bits, but a great many lessons learned and special memories to reminisce upon in the future. I know I'm preaching to the choir with this one, but there are few things as magical as traveling alone and exploring a side of the outdoors you hadn't encountered before. It's hard to explain, but I love just parking somewhere and walking into a part of the brush where few people go, if ever. It's freeing in a sense.

 

But for now, I've creek walked way too much. I'm gonna go hunt a roadcut or something 

 

 

Edited October 24, 2022 by EPIKLULSXDDDDD
Formatting

[historianmichael]

Very cool! I haven't seen many Ozan echinoids shared online. The regular urchin that sadly didn't make it out is quite a find.

[JohnJ]

Congratulations on a series of good finds.  That regular echinoid is rare and wonderful.

[Manticocerasman]

Nice report and beautiful finds.

 

[sharko69]

Great stuff! Thanks for sharing.

[erose]

Great reports. Searching the creeks (mostly east) can be hit or miss.  You definitely hit those.

[Mikrogeophagus]

@erose The chance of getting skunked certainly makes the good days even better. 

[Tidgy's Dad]

Nice report and some super finds.

[FranzBernhard]

On 10/24/2022 at 10:38 PM, EPIKLULSXDDDDD said:

Apologies for the dramatic title. I thought it sounded cool and stuck

Don´t worry, I did the same a few years ago:

400 Million years in 4 hours - Fossil Hunting Trips - The Fossil Forum

 

On 10/24/2022 at 10:38 PM, EPIKLULSXDDDDD said:

I was suddenly attacked by a hive of wasps

This occurs about every 10 years to me, I am counting 3 attacks at the moment, all with less than 10 stings, fortunately. Yes, its quite worrisome, when you can not escape quickly.

 

On 10/24/2022 at 10:38 PM, EPIKLULSXDDDDD said:

I tried my best to get her attention without spooking her (keep in mind I look and smell like a swamp monster at the moment)

I know that situation also very well. It occurs from time to time, unfortunately. Wasps, spooking and the like - the fate of the prospectors...

 

Great report and great finds, btw .

 

Franz Bernhard