Crinoids, Trilobites, and a Shark! A 300 Million Year Old Adventure with the Austin Paleo Society.

[Mikrogeophagus]

There are few reasons why I would ever wake up at 5 am and begin a two and a half hour drive out to the middle of nowhere. When I saw that the PSoA was heading out to the Brownwood area, I knew it was an opportunity too good to pass up. Everything I had hunted prior might as well have been buried yesterday when compared to the mind-blowing ages of Pennsylvanian and Permian rocks. It's still crazy to think that those formations were roughly three times the age of the oldest stuff I'd seen before. When I peeled out of the parking garage to begin my drive under the stars, I didn't feel an ounce of fatigue. Instead, every part of me was overflowing with a general eagerness to explore a fantastic new chapter in the story of life on Earth. 

 

Not so long after the sun had risen, I finally spotted a glint of morning light reflecting off the end of a caravan of parked cars along the roadside. I abruptly shook off the daydreams of petalodus teeth and crinoid crowns as I got myself parked and arranged my tools. Melvin, the trip organizer, was quick to introduce himself and gave a run down of the day's itinerary along with what we were looking for. I must admit I was a little disappointed when he told me that petalodus, or any sharks for that matter, were not really known from either of our destinations. Nevertheless, there was still some pretty amazing things to find and he was adamant that the excursion would be an enjoyable experience for everyone.

 

The first stop was in the Adams Branch Limestone of the Canyon Group, along a crumbly, slanted roadcut. No matter where I looked, the ground was buried in crinoid stems, bryozoans, and various shell bits. Carefully maneuvering my way around the cactuses, I poked and pried through the rubble at an area Melvin said was productive for smaller specimens. Faintly, I could hear the conversations up the road being carried by the wind. Some of the other folks in the party were repeat customers of the site and were on the search for trace fossils of starfish coming from an elusive layer. My involuntary eavesdropping came back to bite me when I found a strange little fossil that looked just like a leg of a starfish. When I proudly presented it to Melvin and the folks searching for traces, they kindly informed me that it was a piece of crinoid arm .

 

Hash plates from the Pennsylvanian site. The one on the bottom is my favorite.

 

Once I got back to my spot, I decided it was probably best to save show and tell for after I had some time to cool down and really think about my what I picked up. Luckily, the next few finds were pretty easy to identify simply off of my prior research (sporadic googling). First, I found some really pretty hash plates. Each one is like a slice of Paleozoic sea floor with so much detail it's impossible to not lose your train of thought when staring into them. Next, I snagged a handful crinoid plates and spines. When I reached down for what I thought was another plate, I stopped dead in my tracks. Laying before me was a beautiful crinoid crown.

 

Ethelocrinus magister crown.

 

The day continued on with neat little brachiopods, straight-shelled nautiloids, and the usual suspects. We had probably been there for a couple of hours when we got the heads up that we would soon be moving to our next location. There was definitely a little added sense of urgency to my movements from then, but I still made sure to thoroughly inspect every nook and cranny. As my eyes frantically shifted across the ground, I briefly spotted a small object of interest before losing it. With time running out, I tried to retrace where I had looked and thankfully I was met with a familiar image. When I picked up the tiny, black geometric stone, I noticed white pitting all over one of its side. If I hadn't seen something similar online before, I may have tossed it. At the time, I couldn't remember the name, but I had a gut feeling this could very well be the crusher shark/chimera, deltodus. I got to talk with Melvin one last time before we left the area. I was already pretty happy with the crinoid crown, but Melvin's excitement was contagious and made me feel even better. I took the opportunity to also show him the possible shark tooth. He seemed intrigued, but we couldn't come up with an ID for it at the time.

 

Deltodus

 

~

 

After a quick break, we conga lined our way 45 minutes north to our next site. A short hike with lakeside scenery later, we arrived to an outcrop of Permian limestone on a private ranch. Melvin explained that this site was known to produce trilobites, unlike our first stop. At that moment, I set myself on finding at least one so I could cross that major trilo milestone in every fossil hunter's career.

 

Permian outcrop

 

From afar, the ground looked pretty similar to before. Upon closer inspection, however, I noticed a wide variety of brachiopod species I helped myself to. A lot of people were discussing the brachiopod, Wellerella which is known for its zig-zagged appearance. One person brought along his golf ball-sized specimen. In the field, the biggest I could find was the size of a pea . Thankfully, the lack of luck with brachiopods was paid back in full when I found my first trilobite!.. and another... and another!

 

The two best pygidium trilos. The left one was curled in and flattened, so it appears to have some of the head still attached. I have no idea on any possible species, so I welcome any input from our resident trilo experts.

 

The sun was reaching its apex and the temperatures rose accordingly. Lots of people called it there and the majority decided to head home after a long day of hunting. I and another family chose to stick it out just for a little longer; we drove all this way after all. Me and Brian, the father of the family, had a nice talk about our lives and the hobby (with our heads locked on the ground of course). I don't know many fossil enthusiasts in my personal life, so it was refreshing to be able to speak face to face with someone who had similar interests. Hopefully, we'll see each other again on the November trip to Brownwood.

 

Here are some pictures of the finds:

 

Pennsylvanian crinoid bits and bobs. The centerpiece is my "starfish arm" .

 

Pennsylvanian Orthoceras?, Deltodus, various bivalves, and Euphemites? gastropod

 

Pennsylvanian Lophophyllidium horn corals, various corals?, various brachiopods. The bigger one (Neospirifer?) I might get cleaned by someone else. It's complete and I don't want to mess it up. Far right Derbyia?

 

Delocrinus inflexus? and Ethelocrinus magister

 

Permian Neochonetes

 

Permian brachiopods. Top right Juresania?, bottom right Wellerella, middle top Composita.

 

Permian crinoid bits and bobs. One of the spines is regenerating.

 

Permian horn corals, and Archeocidaris plates and spines. I like the spiky spines.

 

And lastly an enigmatic Permian find. Some kind of weird brachiopod? Could be weird cephalopod maybe. Has symmetry. Outside looks "woody".

 

Thanks for reading!

Edited October 15, 2022 by EPIKLULSXDDDDD
Formatting

[Top Trilo]

Awesome finds! Of course the trilobites are my favorite, and even cooler because they're Permian. Do you know what formation they're from? They look similar to Ditomopyge but I am not an expert.

[JohnJ]

It's easy to lose yourself in the sheer volume of fossils at those sites.  Congrats on your finds.  

[Tidgy's Dad]

Wow! 

Nice report and some great finds. 

[FossilDAWG]

That's what I'd call a successful trip!  I especially like the crinoids, but the whole lot is pretty fantastic.

 

Don

[DPS Ammonite]

Great stuff.

 

What was the name of the Permian formation that yielded the trilobites? Was the site just east of Texas Highway 279 between Cross Plains and Pecan Bayou? I am trying to properly label my finds possibly from that site.

Edited October 15, 2022 by DPS Ammonite

[erose]

On 10/15/2022 at 11:52 AM, DPS Ammonite said:

Great stuff.

 

What was the name of the Permian formation that yielded the trilobites? Was the site just east of Texas Highway 279 between Cross Plains and Pecan Bayou? I am trying to properly label my finds possibly from that site.

The Permian site is at Lake Sealy just NE of Santa Anna. We(PSA) have to get permission to collect but it is land that I think is owned by the town or county.  My notes have this as:

 

?Moran Formation, Cisco Group
Wolfcamp Series, Permian*

PSoA Field Trip site

* based on Brownwood Sheet, Geologic Atlas of Texas, TXBEG, 1976, area is mapped as Santa Anna Branch, Sedwick, and Moran Formations undivided. Assuming eastern side of outcrop band is most likeley Moran.

 

The matrix and fossils suggest lower most Permian. The question mark is mostly because we are hunting material dug up from the creation of the lake. Texas is full of lakes and 99% of them are man-made.

[erose]

4 hours ago, Top Trilo said:

Awesome finds! Of course the trilobites are my favorite, and even cooler because they're Permian. Do you know what formation they're from? They look similar to Ditomopyge but I am not an expert.

Ditmopyge is supposedly a Pennsylvanian species. Finsley(1996) suggests Delaria as a Permian species. But there are a few other possibilities. We would need to be able to see better views of a complete glabella or pygidium for analysis.  

 

I wish I could say for sure but I haven't ever gotten around to fully identifying what I collected there several years ago. And I have some good rollers with distinct features.  The problem is that the Pennsylvanian seems to just blend right in to the Permian here in Texas and the fossils appear very similar.

[erose]

I was so glad to learn from Melvin that the field trip was a success. He told me that someone had found some descent crinoids at the first site. By the way, the Adams Branch is just the light colored limestone that caps the road cut. Below it the brown shales and mudstones are the Strawn Group undivided Missouri Series (Pennsylvanian Period)

 

And those crinoids are pretty good specimens for that site. I wish I had been able to join you all. I will not miss the November trip for sure!

 

I am not surprised that you found a tooth. And Deltodus is a strong contender. That is an excellent find. Although not common teeth can show up in almost any of those Pennsylvanian exposures.  But the chances of finding a nice Petalodus or any other teeth is much better at a spot like Wilson's Clay Pit or Lake Jacksboro.

 

[Mikrogeophagus]

58 minutes ago, erose said:

?Moran Formation, Cisco Group
Wolfcamp Series, Permian*

 

5 hours ago, Top Trilo said:

Do you know what formation they're from

 

3 hours ago, DPS Ammonite said:

What was the name of the Permian formation that yielded the trilobites?

 

I wasn't sure on the formation so I didn't list one. On USGS, the site lies pretty much on the border of the Moran Fm and Pueblo Fm. Thanks for the geology info @erose!

[Bringing Fossils to Life]

Those cephalopods are amazing!

[PaleoPastels]

WOW. These pictures take me back!  Drooling over those crinoids. I used to live in Indiana where we had a plentiful amount of trilobites and crinoids and I regret not picking up more of them. I always forget we have some here in Texas too! I found my first Texas crinoid column the other week and it was so nostalgic. Indeed that looks a lot like a Neospirifer to me- I have a few from up north. I love the spines you found as well! It seems like you had an amazing learning experience out there with some very great guidance- Im jealous! Thats a very nice aboral cup you found, congrats!

 

I love your “sea star arm” story omg that made me smile.  
 

I  totally feel you on feeling that rush of excitement before a trip. I work a 3rd shifter and right after work on weekends I fossil hunt in the morning into midday- all of that fatique just disappears and turns into seratonin & wonder. Someday you’ll get yourself a petalodus tooth!  You’ve been all over Texas now, wow! I also sympathize on not knowing a lot of people in person interested in paleontology, you are always welcome to meetup with me! 

[Mikrogeophagus]

@AmmoniteDelight It really was an unforgettable trip! I’m going on this months trek to brownwood so I’m hoping to catch a petalodus then! 
 

I might take you up on that offer once I’m back in dfw! It could be cool to also set up like a general fossil forum get together/hunt some time for all of the local members.

[PaleoPastels]

2 hours ago, EPIKLULSXDDDDD said:

@AmmoniteDelight It really was an unforgettable trip! I’m going on this months trek to brownwood so I’m hoping to catch a petalodus then! 
 

I might take you up on that offer once I’m back in dfw! It could be cool to also set up like a general fossil forum get together/hunt some time for all of the local members.

I wish you the best luck on a petalodus tooth, keep me updated! 
 

The offer definetly still stands! Id love to meet ya! Drop me a DM and we can figure out a time and place. Just a heads up I overdue it the the snacks and if there’s a reptile- I will catch it and carry it around for a while like a kitten. 

[Sjfriend]

On 11/10/2022 at 1:50 PM, AmmoniteDelight said:

 Just a heads up I overdue it the the snacks and if there’s a reptile- I will catch it and carry it around for a while like a kitten. 

Sounds just like my field trips Sometimes my reptile trips get interrupted by fossils