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Highlights of a jam-packed January (Jan, 2023)

Jared C


Hi all, it's been a minute since I've written a report and I think I'm due :)


To start: This last January I got to be a part of two special discoveries in the marine reptile realm. Though not made directly by me, I'm still glad I got to be there. I'll detail them below:


Early January:

Last summer, I spent two weeks in North Dakota on the Hell Creek formation, and made some lifelong friends. Two of them (Harry and Piper) arranged a trip down from North Dakota and Florida, respectively, upon the discovery of cheap flight tickets, with the intent of catching up and taking a tour of the Texas Cretaceous. Our weekend was spent well - many laughs, drinks, mishaps (like my catalytic converter getting stolen :DOH:), long drives admiring the city lights in my parent's car that they graciously lended me for the remainder of the weekend, and of course....plenty of fossils.


The first day was spent gravel hunting - not much came to show from it save for a well preserved (for these creeks) mosasaur vertebra. I was of course very happy to see this, as verts in this watershed are a rarity.





The next two days were devoted to the Eagle Ford - one site being a bust on stuff that's worth flying down for - but the next site which we attacked on Sunday produced the best find of the trip.

This site is my "if we get skunked, it's our last resort" site - there's always something wonderful to be seen there, and when you have a site like that in your back pocket, it's not something to pillage - best kept for special occasions like this!


My hope was that I could get Piper and Harry hooked on some beautifully preserved Cretoxyrhina and Ptychodus, and, if we were lucky.... a Pliosaur tooth. What Piper actually ended up finding was so rare it wasn't even one of my list of realistic goals for seeing that day...


We arrived at the site, and while I tried to isolate the elusive fossiliferous layer, I put them on some sections that still had some promise. For both of them, all of their prior field experience is in the North Dakota badlands - so even the act of tapping actual rock and flipping slabs made for an enjoyable and novel approach. 


After 20 minutes or so, I eventually found the sweet spot - that thin, ephemeral, densely packed layer was underwater. Making a huge mess (mud and water everywhere :) ), I pulled out some great slabs and passed them out to be picked at, and then picking at some of my own. 


Here's a fun selection of finds prior to "the big one"



Above: Cretoxyrhina mantelli tooth from Piper in the less rich layers. She found this nearly immediately!




A gorgeous Ptychodus occidentalis that I was happy to see




A Protosphyraena sp. I was happy to see as well. Largely complete teeth from this taxon are not too common for me.




a PERFECT Squalicorax falcatus. It may be a common shark, but I love finding a beacon that can just define an entire species in my collection. I have some other smaller, perfect condition teeth for S. falcatus, but they take on a more posterior position in the mouth. For now, this tooth is my Squalicorax pride and joy. 




Some microteeth showed themselves as well, like this one above. With that size it's hard for me to make a judgment on genus here.


Finally, one rock had a trip-maker. I handed a slab to Piper, turned my back to continue "mining", and immediately hear a casual "I think this is something cool".

Laying loosly on the slab, ready to come flying off with the slightest disturbance, was THIS:



A Coniasaur jaw! That's code for "stupid rare". Here is the specimen under better lighting. 




Those familiar with North American Coniasaurs may notice something unusual - that it's definitely not the North American Coniasaurus crassidens that most Coniasaur finds here get thrown into.

With what's described, that leaves the more conventionally European C. gracilodens, and that doesn't look like a definitive match to me either. For Coniasaurs, it wouldn't be saying anything very extraordinary, as Coniasaur taxonomy has not been properly recorded, but this might belong to one of those coniasaur morphologies floating around without a description. This specimen needs to be looked at under a microscope before a definitive assessment is made though. 


Here's a graphic I composed for it (note none of the pictures are mine though). On the left (A, B, and C) is Coniasaurus gracilodens, on the right (E and F) is Coniasaurus crassidens.  Notice that Coniasaur paleoart is even rarer than the actual animal, so I used art of some other Dolichosaur. It does a good job of representing what Coniasaurus would have looked like anyway.



It was a wonderful find to wrap a wonderful weekend, and this fossil will probably make its way to SMU next. If the folks there don't find it useful for the Coniasaur research they have rolling, it'll make its way back to Florida with Piper.




Fast forward a week:


After one weekend spent fossil hunting a hard, another good one was on the way. This time, my weekend would be devoted to exploring the cenomanian Plesiosaur digsite from July, in search of more bone. My dig partner for the weekend was George, who I met briefly at SMU once by chance, where he was asking around on how to get involved. Unfortunately @Ptychodus04, who (with Joe) I found the specimen with in July, couldn't make it out this time. With his current prep project of a one of a kind green river bird, I can't blame him :P


 It was suggested I show George the ropes the next time I go to my plesiosaur digsite. That might have been a little cruel and unusual, considering how difficult and dangerous that site is, but as you'll soon see, it was well worth it - but not for the reasons you'd expect. 


We spent two days on the site - one half day digging away overburden, followed by a night in a smoky motel-8, and then the next day more tediously removing small chunks of matrix from the cavity at the bone level. In short, we moved maybe 8 inches further into the cavity, with no bone spotted. As I was hunched over, chipping away, George moved further to the right by some feet to explore for a wayward flipper. This was his first field experience, and he crushed it, breezing through the first slabs as he moved in. It did not take long until he let out a triumphant yell. Thankful to stand up, I came over to take a peek at what he had found in his slab, and went completely silent.

It seemed to me that we were looking at a mosasaur tooth...


As a reminder, this is (middle?) cenomanian strata - several million years older than the oldest american mosasaurs. Before we call it though, Polcyn is going to evaluate and prep the tooth personally. But, from photos and my own pre-prep observations, we're both optimistic that it's mosasaur. Next up will be some sampling of bentonite layers for a more precise date. 


Here are some photos:



With that find, the day was a success, even though we didn't find more of the Plesiosaur. 


George and I turned around and started heading home. We had time, so I wanted to make a pit stop to explore a different creek which seemed to have interesting geology after I cross referenced google and geological maps. Fortunately, it didn't take along to find a perfect access point, and from there it didn't take long to find a large shale exposure. This was in the upper eagle ford formation, close to the contact with the Austin chalk, so I was hoping to find the legendary Kamp Ranch shark tooth lenses. We got stopped short by mud and private property though, and we were anyway making slow progress because the geology up until that point was just too interesting. So, we settled down and begin moving into a hill. 


Much to my surprise, we began finding in abundance one of the last fossils I expect to see in the eagle ford - ammonites. 


The average ammonite we'd see looked like this - detailed but otherwise in poor condition:



Some other good specimens began appearing, thought still flattened:



After 30 minutes, we eventually came across a a partially 3D specimen:



This was a welcome change from being hunched over for hours in hard rock searching for a humongous marine reptile. This day, we got the best of both worlds!

For now, I'm stuck between Colignoniceras woolgari or Prionocyclus sp. as Prionocyclus hyatti also looks convincingSuggestions are welcome :) 



Those were the January highlights, but I would like to take a moment on a February find as well- my first Saleniid ever.


Other male fossil hunters might relate to me with this one. When you're this hopelessly obsessed with the hobby, your brain can come up with few date ideas more appropriate than dragging a pretty girl through some muddy creek to look for sea urchins with you. In retrospect, always a terrible idea,  but if she sticks it out you found the one :BigSmile:


Fortunately we didn't get skunked, so she didn't think I was crazy - because we actually made a good find I wasn't expecting. This site is the legendary Comanche Peak shale micro site that I've praised on a few trip reports before. Between my step brother and I, two Tetragramma (one of them gargantuan) have been found, and dozens of Heteraster - but all in the tiny shale section. The shales are encased in limestone, which I noted to be decidedly more barren in previous visits. But, this time - I almost immediately noticed a wonderful geometric pattern in the limestone roof above me:






BOOM! I was definitely ecstatic about this. Careful chiseling got it out safely, in a condition to be prepped at home:



Pre-prep, I'm tentatively assigning it to Leptosalenia mexicana. For the prep, I think I'll have to use acid for the first time, painting the exposed urchin in paraloid and dunking the rest in vinegar for a day, water for a day, and then repeating. If anyone has a tip or trick that they like for acid prepping urchins, I'm all ears :) 


On a total side note, we made an even rarer discovery soon after - though not a fossil. After moving on from the sea urchin spot, we found a newly made walkway that ran by the most perfect, untouched climbing boulder I have ever seen. For anyone reading this who also boulders, you would agree that boulders that have flat landings, excellent top-outs, and solid holds, all while being aesthetically beautiful... are very rare. To find one that is easily accessible and undiscovered by other climbers? That's like finding a unicorn. 


Here's the unicorn in quesiton:




The day after I threw myself at this boulder for a few hours, cleaning the holds and finding routes. I had a dream about it for two nights in a row :heartylaugh:


And so, that was my month. I've been busy, but thankfully not nearly as busy as last semester, so many weekends still give me time to get back out in the field. I have a killer Coniacian spot in mind I want to explore soon, so hopefully I'll be back with a success story.


Hope you all get a chance to kick it in the field soon!


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