Initial Forays into Oklahoma; Ordovician, Permian, Pennsylvanian

[Mikrogeophagus]

Pennsylvanian

 

At long last, I finally made my way across the Red River and into our northerly neighbor, marking off a third state in the list of places I have hunted. While I had originally wanted to visit Oklahoma many times in the past with Austin Paleo, schedules seemed to never quite sync up. However, a timely road trip to Missouri for family brought a convenient moment to stretch my legs by the highway.

 

This particular site in question is a regular of Dallas Paleo for some years. It seemed they weren't planning another visit in the near future, so I assumed a brief hunt of my own wouldn't be an issue. This spot is seated in the Savanna Formation of the Desmoinesian Series which makes it roughly the same age as the Mingus Fm and other Strawn Group strata of North and Central Texas. In contrast with what are usually marine dominated rocks in Texas, this site is specifically known for its abundant terrestrial plant material as it was deposited in a delta plain environment. Despite only a 20 minute visit (heat, chiggers, and my folks waiting in the car), I found a lot of neat stuff that made the trip well worth it.

 

After wading through the tall grass and walking up a small slope, I was quickly greeted by countless fern impressions. They kinda look like Pecopteris or perhaps Neuropteris. I'm not sure how those genera are distinguished though. I was entertained by the visual similarities shared between these specimens and some Cretaceous Woodbine ferns I collected that also originated from an ancient delta plain (though they aren't tree ferns I believe). If you want to see those, they are in my Woodbine album.

 

The first fern of the day

 

The negative of a fern from a nodule

 

The positive found a few minutes later

 

Another fern beauty with great colors

 

In addition to these, I found some pieces of Calamites chunks plus their corresponding leaf clusters, Annularia. On a chunk of grey rock, there were some shiny carbonaceous Neuropteris? leaves plus what appears to be a small seed(?) to the left of the leaf below. 

 

Annularia (Calamites leaf cluster), black Neuropteris?, and seed?

 

It was a fun side trip and helped to whet my appetite for more adventures in Oklahoma to come. Once in Missouri, I didn't do any hunting as we were pressed for time. However, I did briefly look at a huge boulder in the James River during a canoe trip. It was greenish-white limey shale and had many tiny brachiopods on one surface. I reckon there was probably something neat I could have found, but seeing as I had no hammer on me, I didn't give it much time. I guess I'll save the serious hunting in Missouri another day.

 

Permian

 

Since that roadcut visit, I began planning out a trip through a handful of sites not too far from the TX-OK border. I thought it might be better to explore the "coastline" first as opposed to making an arduous journey deep into the state's interior where the pain of getting skunked might be more potent. One obvious destination for this route was Waurika. It had always been a spot at the forefront of my mind. Past reports of it no longer being accessible had given me cause for hesitation before, but after asking a handful of friends who had been there with no issues recently, I decided now was as a good a time as ever to finally dip my toes into this iconic time period. The forecast for the day was set to reach 100F, so I made Waurika my first stop. I'd rather be there early in the morning so that the iron rich rocks of the Petrolia Formation wouldn't have much time to heat up in the summer sun. Heading out in the early morning glow, I surfed the wave of dawn's light on a journey to the west.

 

Upon exiting my car, I was introduced to a couple of stinky dogs from a ranch down the road. They were quite friendly and it was apparent that they weren't going to stop following me, so I entered the site with them in close company. Every time I knelt down to see if I was in the right area for micros, they would ceaselessly try to lick my face and steal my attention. Luckily a rabbit leaped out of the bushes and sent them running after it. I could finally get serious (though I did miss them a little bit)!

 

The first fossil was a common Orthacanthus texensis tooth. These funny lookin things possess two elongated cusps that give them an appearance unlike any other sharks of the geological record.

 

Orthacanthus texensis

 

Shark denticle covered spine

 

I took this to mean that I had stumbled into the right place. Pretty soon, I was finding these little guys left and right. Their serrated cusps were often broken off and difficult to tell apart from one of my main targets, Dimetrodon limbatus.

 

The first non-shark tooth was quite a weird one. It has a broad spatulate morphology that I would say looks very similar to a sauropod like Camarasaurus. The incisal edge of the tooth seems to have poorly developed denticles and the enamel overall is highly textured with what could be described as an anastomosing pattern. The lingual face has a distinct median ridge running longitudinally. I was inclined to believe that this shape of tooth ought to belong to something herbivorous, so my tentative ID was either Diadectes sideropelicus or Cotylorhynchus (hard to find good photos online of Cotylorhynchus teeth). I took the specimen into the Texas Through Time Museum and a couple of the staff instead suggested Archeria, but I am suspicious of that. I was hoping to buy a copy of the Waurika Vertebrate Fauna book by Kieran Davis at the museum to help with ID, but it seems those went out of print and are no longer in stock.

 

Lingual view (note median ridge and incisal denticles)

 

Side view

 

Labial view

 

Another spatulate specimen takes on a very different morphology. I am hopeful that it could be Diadectes sideropelicus.

 

Diadectes sideropelicus?

 

Diadectes sideropelicus?

 

Diadectes sideropelicus?

 

The title of most common non-shark tooth belonged easily to the Temnospondyl, Eryops megacephalus. When I saw the toothy grin of the cast specimen of this species at the Texas Through Time Museum, it was easy to understand why this was the case. These are identified by their prominent ridges that run longitudinally all around the circumference of the conical tooth.

 

Eryops megacephalus

 

This next enigmatic tooth may simply be an oddly shaped Orthacanthus tooth, but I thought I'd throw it in just in case it's something cooler. It has a labiolingual curvature, serrated edges, and robust, chisel-shaped build. There is only very faint texturing to the enamel, but stronger texturing than the completely smooth blades of Orthacanthus. Additionally, both the mesial and distal edges terminate before reaching the enamel-cementum junction which is not the case for my shark teeth. I think this may be Secodontosaurus obtusidens as seen in Figure 5a of 10.1038/ncomms4269 since I read that they are labially convex and possess serrations. This taxon is described as having thick carinae, but I cannot say for sure if that is what's seen here.

 

Secodontosaurus obtusidens?

 

 

Moving on, I have a couple of specimens that I am much more confident in. Both teeth have strong enamel texturing and serrated edges. A key characteristic is the longitudinal fluting. I saw this mentioned in an old thread by @dinodigger as something found in primitive Dimetrodon species such as D. limbatus. 

 

Dimetrodon limbatus

 

It is often difficult to tell the serrated teeth of Dimetrodon and Orthacanthus apart, and one must look for distinguishing features such as textured enamel for a chance at ID. I noticed that the cross sections of the two above teeth look quite different from my similarly sized and shaped shark teeth. The pulp chambers on Orthacanthus are generally spindled shaped and the borders are the same distance from the outside of the tooth in all directions (consistent dentin + enamel thickness). In contrast, the Dimetrodon teeth have circular pulp chambers and varying dentin + enamel thicknesses. Perhaps this could be an additional tool for distinguishing the two.

 

 

Left are Orthacanthus; Right are D. limbatus

 

In addition to teeth, I may have found a Dimetrodon caudal vert:

D. limbatus caudal?

 

To round of the finds, here are an assortment of smaller teeth and claws.

 

Claws

 

Ophiacodon retroversa?

 

Trimerorhachis insignis?

 

Unknown

 

After a solid four hours of hunting, the sun was getting high and the heat was picking up. I had some more spots a long drive away that I needed to hit, so eventually I cut things off and made my way to the car, satisfied with a pocket full of fossils and some bags of micro matrix .

 

Ordovician

 

The Ordovician was an obvious choice for me since it is pretty hard to find quality fossils from that geologic period when searching in Texas. On my map, I had a little spot circled for chances of Bromide Formation trilobites (Early Sandbian). When I pulled up to the site, I initially had little luck in finding anything other than rock solid limestone and flying bugs. The temperature was hitting its forecasted peak and the humidity began eating away at me. My shirt quickly dampened, and it soon appeared as if I had just gotten out of a swimming pool. As I traveled through lower and lower parts of the outcrop, however, I eventually reached a shaded spot that had some brachiopod bits and softer matrix. I was thankful to take a seat and study the brachs a bit closer as I caught my breath and quenched my thirst. After following a chain of crinoid stem fragments I locked onto a reddish colored array of various shapes. It was a fragile mess, but very clearly a smattering of trilobites! I was in the right spot after all...

 

Red trilobite parts in the Pooleville Member of the Bromide Formation

 

The layer quickly proved to be extremely rich. Everywhere I looked, I could find at least a trilo bit if I squinted hard enough. I knew it was only a matter of time before I could grab a better specimen.

 

More trilobite parts

 

Interrupting the steady flow of trilo finds, I snagged a neat brachiopod and some sort of cephalopod!

 

Oxoplecia gouldi? before and after

 

Unknown cephalopod

 

Then, nestled in a little crevice atop a limey slab, I saw a perfect roller just begging to be freed. To clean it up, would using vinegar be a bad idea?

 

Frencrinuroides capitonis?

 

A single step away...

 

Homotelus bromideensis? thorax and pygidium

 

Calyptaulax annulata or Calliops armatus?

 

I then came across a weirdly shaped fossil that resembled the preservation of the previous trilobites, but its shape was hard to figure out. Some searching online showed Probolichas as something similar, but it could very well just be a random shell. I believe Probolichas is quite a rare genus so its unlikely.

 

Probolichas?

 

Rounding out the trilo finds was a beautiful Nanillaenus punctata? I think it will prep quite well, but I don't know if I trust my skills or tools. Perhaps I will get it professionally done.

 

The top right is the most promising specimen (Nanillaenus punctata?)

 

Trilobites were not the only stars of the show, however. I found a complete crinoid crown and I am hopeful that arms may preserved within the rock it came from!

 

Hybocrinus crinerensis?

 

Eventually, I walked far enough to enter the lower member of the Bromide Formation, known as the Mountain Lake Member. It is comprised of older shales that were deposited before a sea level rise (hence why the younger Pooleville is limestone). There were some pretty hashplates that I wish I could have searched through more thoroughly, but I was running out of water and had to make it back to the car. I at least caught a pic of a Mountain Lake trilobite as I was walking by.

 

Homotelus bromideensis?

 

On the drive home I got to stop by my Albian micro shark spot to collect some bags of matrix for my future guide. I was lucky and managed to spot a little ray tooth while filling the bag.

 

It was an exhausting day in a part of the year when really no one should be outside. Thankfully, it also turned out to be one of the most enjoyable adventures yet. Despite being within a two hour drive of DFW, Oklahoma had always felt so distant. For some reason the state border had been a mental boundary for me. Now it feels as though a whole new frontier has opened up just a stones throw away. 

 

Thanks for reading!

 

[Fossildude19]

Great reports and finds!

Thanks for sharing them.

[minnbuckeye]

Great trip report! In particular, I love your Permian finds. At least at that high temperature, you found the site drier than I did!

[Notidanodon]

Great report!

[Kane]

Very nice! I don't see enough Texas Ordovician material posted around here, so that in particular was a real treat.  

[Denis Arcand]

Interesting report! I didn't know we can find Ordovician material in Texas. I particularly like the small cephalopod and the crinoid crown 

[hadrosauridae]

Great trip!  Your permian finds are amazing! 

[Mart1980]

Oh wow, you put a lot of effort into the report. Very fun and educational to read, thanks for sharing 

[FossilDAWG]

Great report!  You certainly had some good luck at some of those sites.

 

Just for clarification, am I correct in thinking that Ordovician Bromide Formation site  was in Oklahoma, not Texas?  Some people seem to have the opposite impression, so it’s worth clearing up.

 

Don

[Mikrogeophagus]

@FossilDAWG @Kane @Denis Arcand Yes it seems I was not clear in my writing. The Ordovician site was indeed Oklahoman! Ordovician stuff is difficult in Texas, but I do have a special site I'd like to try in the future if I can secure landowner perms . The Llano region is a very intriguing...

 

@minnbuckeye I'm thankful for not having to crawl in mud! Makes spotting micros way to hard

[JohnJ]

Great report, Tyler!  

[LSCHNELLE]

You write great trip reports! And you always know how and where to zoom in on fossil teeth. It just amazes me that you can tell them all apart. Congrats!

[old bones]

Great trip report! I enjoyed seeing all of your cool finds.

[ThePhysicist]

Very nice report and finds, as usual! Very jelly of the Dimetrodon teeth. Man, I've got to do some Permian huntin later this year.

 

23 hours ago, Mikrogeophagus said:

It is often difficult to tell the serrated teeth of Dimetrodon and Orthacanthus apart, and one must look for distinguishing features such as textured enamel for a chance at ID. I noticed that the cross sections of the two above teeth look quite different from my similarly sized and shaped shark teeth. The pulp chambers on Orthacanthus are generally spindled shaped and the borders are the same distance from the outside of the tooth in all directions (consistent dentin + enamel thickness). In contrast, the Dimetrodon teeth have circular pulp chambers and varying dentin + enamel thicknesses. Perhaps this could be an additional tool for distinguishing the two.

Glad to hear we've arrived at the same distinguishing features 

 

23 hours ago, Mikrogeophagus said:

took the specimen into the Texas Through Time Museum and a couple of the staff instead suggested Archeria, but I am suspicious of that. I was hoping to buy a copy of the Waurika Vertebrate Fauna book by Kieran Davis at the museum to help with ID, but it seems those went out of print and are no longer in stock.

Not Acheria - they have backswept chisel-tipped crowns and are usually quite small:

Holmes, Robert. "The skull and axial skeleton of the Lower Permian anthracosauroid amphibian Archeria crassidisca Cope." Palaeontographica. Abteilung A, Paläozoologie, Stratigraphie 207.4-6 (1989): 161-206.

 

Re. the "spatulate" teeth, I think you've narrowed the options quite well. Both Diadectes and caseids possess teeth like those. I haven't studied them enough to say much more.

 

Diadectes teeth from the WMNH:

 

See below for caseid teeth:

Reisz RR. 2019. A small caseid synapsid, Arisierpeton simplex gen. et sp. nov., from the early Permian of Okla- homa, with a discussion of synapsid diversity at the classic Richards Spur locality. PeerJ 7:e6615 http://doi.org/10.7717/peerj.6615

 

23 hours ago, Mikrogeophagus said:

Additionally, both the mesial and distal edges terminate before reaching the enamel-cementum junction which is not the case for my shark teeth. I think this may be Secodontosaurus obtusidens as seen in Figure 5a of 10.1038/ncomms4269 since I read that they are labially convex and possess serrations. This taxon is described as having thick carinae, but I cannot say for sure if that is what's seen here.

See Reisz et al. 1991 for a description of Secodontosaurus' dentition:

 

"All the preserved maxillary teeth have anterior and posterior cutting edges, but they lack serrations. The anterior cutting edge is present only along the apical half of the tooth and extends from the medial surface basally onto the anterior edge apically. The posterior cutting edge extends vertically almost the entire height of the tooth... The anterior dentary teeth are slender and sharply pointed...All the preserved dentary teeth have cutting edges of similar design to those on the maxillary series and also lack serrations." (Reisz et al. (1991))

 

ROBERT R. REISZ, DAVID S. BERMAN, DIANE SCOTT, The cranial anatomy and relationships of Secodontosaurus, an unusual mammal-like reptile (Synapsida: Sphenacodontidae) from the early Permian of Texas, Zoological Journal of the Linnean Society, Volume 104, Issue 2, February 1992, Pages 127–184, https://doi.org/10.1111/j.1096-3642.1992.tb00920.x

 

Re. the Ophiacodon teeth, how'd you make that ID?

 

(If you need access to any of these papers, let me know.)

[hadrosauridae]

On 7/6/2024 at 12:13 AM, Mikrogeophagus said:

 

I was hoping to buy a copy of the Waurika Vertebrate Fauna book by Kieran Davis at the museum to help with ID, but it seems those went out of print and are no longer in stock.

 

 

The original is out of print, but the author has combined the first 2 permian books.  The only place I know to purchase is from his website.  Shipping from GB isnt cheap, but its an amazing reference book and I highly recommend it.  He also has a book just on the permian fish / sharks

 

https://www.rhyniechert.com/permian/waurika_oklahoma

 

Theyre also on the "electronic gulf" website under the title of "Lower Permian Vertebrate Fauna of Waurika Oklahoma SB Fossil Book brand new"  and "Permian Sharks & Fish of Texas & Oklahoma. Red Beds, teeth, petalodonts NEW book"

[Mikrogeophagus]

@ThePhysicist Thanks for the super informative thoughts as well as citations (I need to start incorporating those more in my own posts)!

 

13 hours ago, ThePhysicist said:

Both Diadectes and caseids possess teeth like those.

Glad you agree. I'm looking over that caseid article you linked. Though not a perfect match, I'm seeing a lot of similarities in Figure 3A of the Oromycter premax and am leaning a little more towards caseids now. The shape, texture, and "denticles" I noted are all present. I can see listed in the Waurika book's table of contents the following caseids: Cotylorhynchus, Oromyctes, and an undescribed caseid. I guess those are my best bets for now. I love the shrunken heads on those guys .

 

13 hours ago, ThePhysicist said:

"All the preserved maxillary teeth have anterior and posterior cutting edges, but they lack serrations. The anterior cutting edge is present only along the apical half of the tooth and extends from the medial surface basally onto the anterior edge apically. The posterior cutting edge extends vertically almost the entire height of the tooth... The anterior dentary teeth are slender and sharply pointed...All the preserved dentary teeth have cutting edges of similar design to those on the maxillary series and also lack serrations." (Reisz et al. (1991))

Hmm this is interesting. First, this article states that their specimens lack serrations whereas the article I looked at claims Secodontosaurus possesses serrations (10.1038/ncomms4269), so I'm not totally sure of what to make of this feature. Second, it mentions the anterior carinae spanning only the apical half of the tooth. Initially this confused me because in dental school the term "apical" means towards the apical foramen at the extreme ends of the tooth's root (opposite to "coronal" which means towards the crown). It seems in paleontology, "apical" is flipped to mean towards the tip of the crown and is opposite to the word "basal". Anyways, the anterior carinae on my specimen seems to match your articles description in that it reaches from the tip of the tooth down to about mid-way along the crown height. The posterior carinae also seems to match as it travels almost the entire span of the crown, but ends a little before the cementoenamel junction, which is why you underlined that section of the quote I presume.

 

14 hours ago, ThePhysicist said:

Re. the Ophiacodon teeth, how'd you make that ID?

Honestly I just saw Ophiacodon teeth on the online auction site preview for the Kieran Davis Waurika book and thought they looked similar . Not confident at all and was more so including them to see if anyone would jump out on here and say if they are or aren't correctly identified. They are just a few non-serrated + non-striated teeth in the moderate size range. 

 

@hadrosauridae It certainly seems like a really well put together book. I think I'll have to drop the money on it once I have a convenient excuse like a birthday . Luckily that shark book looks a lot cheaper, so maybe I'll grab that once I find some more species in my micro matrix.

 

[connorp]

Nice report! Your “Unknown Cephalopod” is actually the gastropod Phragmolites. Your nodule fern is Alethopteris.

[ThePhysicist]

On 7/7/2024 at 2:01 PM, Mikrogeophagus said:

First, this article states that their specimens lack serrations whereas the article I looked at claims Secodontosaurus possesses serrations (10.1038/ncomms4269), so I'm not totally sure of what to make of this feature.

Same, except in Fig. 5. of Brink & Reisz I can't discern any serrations, even minor. You'd think they'd have better images like those for Dimetrodon. Could contact the authors?

 

On 7/7/2024 at 2:01 PM, Mikrogeophagus said:

Initially this confused me because in dental school the term "apical" means towards the apical foramen at the extreme ends of the tooth's root (opposite to "coronal" which means towards the crown). It seems in paleontology, "apical" is flipped to mean towards the tip of the crown and is opposite to the word "basal".

Interesting, guess that happens when two fields develop terminology independently lol.

 

On 7/7/2024 at 2:01 PM, Mikrogeophagus said:

Honestly I just saw Ophiacodon teeth on the online auction site preview for the Kieran Davis Waurika book and thought they looked similar . Not confident at all and was more so including them to see if anyone would jump out on here and say if they are or aren't correctly identified. They are just a few non-serrated + non-striated teeth in the moderate size range.

Okay, I've been looking for publications on its dentition, but haven't found one adequate to identify. I've several kinds of conical teeth and just not sure where to place them... If anyone wouldn't mind PM'ing us those relevant pages from KD's book that would be great.

[Ironhead42]

On 7/7/2024 at 9:18 AM, hadrosauridae said:

 

The original is out of print, but the author has combined the first 2 permian books.  The only place I know to purchase is from his website.  Shipping from GB isnt cheap, but its an amazing reference book and I highly recommend it.  He also has a book just on the permian fish / sharks

 

https://www.rhyniechert.com/permian/waurika_oklahoma

 

Theyre also on the "electronic gulf" website under the title of "Lower Permian Vertebrate Fauna of Waurika Oklahoma SB Fossil Book brand new"  and "Permian Sharks & Fish of Texas & Oklahoma. Red Beds, teeth, petalodonts NEW book"

 

You can also find these books from the author (user sdfossils) on online auction site. I have recently purchased them from him. Not cheap, but great reference books.

[Ironhead42]

Also, these are great finds. Thank you for sharing. I have yet to find an Ordovician site this nice in my Oklahoma explorations.