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Well, it's taken me a lot longer than I thought it would to write the second part of this trip report, mostly because I've been busy with school and several trips to other places across Texas collecting fossils, but also because I must have made about nine trips to the particular Eagle Ford formation creek site I wrote about in the first post. I've got a lot I could say, but I'll narrow it down to just the most exciting finds - I've still got another trip report covering two trips I took to Jacksboro/Mineral Wells and Post Oak Creek to write as soon as I'm done with this one! I'll link that first trip report here for anyone that wants to read it: http://www.thefossilforum.com/index.php?/topic/126948-texas-shark-tooth-extravaganza/&tab=comments#comment-1377551 As I had located the specific lense in the shale with the most shark teeth on the very same day that I discovered the site, the next couple trips were spent breaking it up further and seeing what else I could find in the exposed sections. Although I came away with a respectable haul of nicely-preserved teeth I didn't find anything I hadn't already found before. Getting bored of finding the same Ptychodus and Squalicorax teeth I decided to climb up the small and now-dry waterfall that stemmed from a creekbed sitting almost on top of the shark teeth lense in the shale. I figured that it would be easier to look down and break up the rock layers than to look up at them above my head and hope they didn't land on me when ever I pulled out another chunk. Here's a picture of the site with the waterfall to the left. You can follow the bentonite seam from the right to the left with your eyes to see where the lense crops up in the creekbed (it's the sort of dark crevice just above the waterfall ledge). Very quickly I was rewarded for my exploration as I pulled out the largest Ptychodus tooth I had ever seen (at the time - a little hint as to what I'll be talking about in my Post Oak Creek trip report ). I'm generally pretty clueless when it comes to identifying most Ptychodus down to the species level, so if anyone could help me out I'd really appreciate it! Here's an in-situ picture: And another picture taken after I had broken it out of its rocky prison: With my enthusiasm rekindled I kept digging through the shale and was rewarded by another Ptychodus tooth, even larger than the last, that actually popped out directly into my hand before I had even seen it. I didn't get a picture at the time but it is in this photo I took after I got home. It has some really interesting surface wear that I reasoned was probably accrued during the shark's lifetime. Directly behind where I found the two Ptychodus teeth was the find of the day and maybe even the find of the year, although I didn't know it at the time. This is a picture of it still in-situ if anyone wants to take a guess as to what it was: It was a mosasaur vertebra! And the largest piece of bone I had found at the site so far, many times larger than the coniasaur vert from the previous trip. This is what it looked like out of the shale back home when viewed from the bottom: One of the transverse processes can be seen on the right as well as the two attachment points for the haemal arch, which is sort of like the spine that's on top of each vertabra but located on the bottom in the vertebrae that make up the tail. Now at the time I didn't think this individual vertebra was anything special. I had found mosasaur vertebrae before at the North Sulphur River, many of which were much larger than this one and in much better condition. I was pleasantly surprised that I had found one at this site but didn't think much of it and so it was pocketed to be looked at later. It wasn't until I got home and had a conversation with @Jared C who is much more informed when it comes to the Eagle Ford than myself that I realized this one bone might be much more important. That's because I had initially assumed that I was looking at the contact between the Eagle Ford and the Austin Chalk, making this particular shark tooth lense I had discovered the famous Atco contact. Mosasaurs are rare in Turonian age rocks but certainly not unheard of (Jared himself even found one two years ago!). But after reading several different university publications on this particular site I realized that this spot wasn't the contact between the Eagle Ford and Austin Chalk, but actually entirely Eagle Ford rock - specifically a subunit that placed it in the lower half of the formation. This meant that this one bone had come from the Cenomanian, not the Turonian, making it slightly older than the oldest known basal mosasaurines, both of which are also from Texas - Russellosaurus and Dallasaurus. Still not believing that I could have possibly been this lucky, I emailed Dr. Polcyn at SMU to get his opinion. He was the one to actually first describe both Russellosaurus and Dallasaurus and so I figured if anyone could tell me whether or not what I had found was significant it would be him. Jared has a pretty good relationship with Dr. Polcyn from his own mosasaur discovery so he was able to tell him to be on the lookout for my email. After a short exchange in which Dr. Polcyn expressed his interest in seeing the vertebra in person we arranged for me to meet him north of Dallas at a plesiosaur dig both he and Jared would be involved in. Meeting Dr. Polcyn was incredible. I've known of him for a long time since mosasaurs have always been my favorite prehistoric animal and he's definitely one of the leading researchers as far as they're concerned. I even remember seeing him interviewed for the news in 2005 when the Dallasaurus discovery was first made public and begging my grandparents to take me to the Dallas Museum to see their mosasaur skeletons. Dr. Polcyn was very interested in the vertebra when he saw it in person and asked me if I would be willing to donate it to SMU alongside the two Ptychodus teeth I had found next to it as they might be useful for dating purposes. I of course said yes as donating a fossil I had found to science has probably been my dream since I could first talk. We made plans for me to go back to the site and collect a large sample of the bentonite from the seam located beneath where I found the vertebra so it can be dated by SMU and the age of the bone confirmed. The bentonite being present at the site is extremely fortunate as it is one of the most conducive materials to dating sedimentary strata. Rounding out my finds for the day that I found the mosasaur vertebra was a pycnodont fish mouthplate: And also another nice coniasaur vertebra (I actually found several more but this was the best and the only one I got a good picture of): Not all of the animals I saw at the site were dead and many millions of years old though. In the same vicinity as the mosasaur vertebra was a toad that I had clearly disturbed in my search for associated bones. I apologized for my intrusion and replaced the front door to his little hole that I had inadvertently dug up. A much less welcome sight than the toad was an absolutely massive wolf spider that I spotted on a clump of shale I had been just about to pick up. On my way back to my car I finally spotted the pack of hogs that been so kind as to create a trail through the woods for me to follow on my first trip. I gave them a wide berth and continued on my way. This site has become one of my favorites, not only because of what I've found there but because I discovered it on my own after a lot of geologic map studying and old paper reading. I can finally say I understand Jared's Eagle Ford obsession! Until next time, - Graham

Five isolated squamata vertebrae found in Central Texas Eagle Ford between 2016 and 2020 were donated to SMU and Dr. Polcyn for study. Dr. Polcyn's email response after receiving the fossils: "There is a nice assortment.... Dallasaurus, Coniasaurus, and the large vert I believe is squamate, but will need more work. I will have to set them aside for now while I finish some other projects but will come back to them at some point in the near future. Thanks for the contribution!"

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 ), 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 . 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 convincing. Suggestions 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 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 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!

I am right now out in the field, attempting to extract a string of articulated reptile vertebrae in the lower Atco. It is in a soft marl bed just a few feet above the basal Atco. There seems to be articulated ribs associated with the specimen, and so far I have uncovered 14 verts. 9 of them were lose of the surface and bagged in ziplocks, but now I am trying to get the rest out. If anyone has any advice, I need it! The specimen also has articulated ribs. I want to get this thing home tonight, and not destroyed. This is is my first time attempting to extract vertebrae, and I want to do it right and get it home tonight. It is currently 8:54 p.m. here in North Texas. Here are some pictures of the bones when I found them and where the dig is now. I don’t know what exactly it is, but I am guessing juvenile Mosasaur. Age is Earliest Coniacian. 9 verts were on the surface, and at least 6 more uncovered with ribs. Pictures incoming: All 9 verts. @Uncle Siphuncle @erose

This last weekend produced probably the best results I've ever experienced while fossil hunting - these last two days will be hard to beat. Before I get to that though, I do want to include a find from the weekend before (since this is the topic of rarity). It was a local find and a first for the species for me. Not only that, but my first real "heartbreaker". It was bound to happen at some point! Sticking halfway out of the gravel, I instantly recognized a large Ptychodus tooth, of either P. marginalis or P. polygyrus - I couldn't remember at the time which of the two was the younger, but regardless both are rare and would be a first for me. (spoiler - it's P. polygyrus)(EDIT: I forgot you don't find polygyrus in Texas - this is probably a P. martini then (also rare, woohoo!). With great anticipation I pulled it out - only to realize that it wasn't half buried - just broken in half! Despite the realization, I was still ecstatic, heightened by the fact that this was on a scout to a new spot as well. But, that't not what y'all are here for, so without further adieu, let's fast forward to my time last weekend. I at first met up with Kris ( @Ptychodus04 ) up in north Texas to take a look at a woodbine site where he discovered the holotype of Flexomornis. That's right, our own forum member discovered north america's oldest definitive bird! It was an estuary-esque deposit, and I was curious about what potential the site had for dinosaur fauna ( a newly inspired interest ever since my time romping around in the hell creek formation). We found some powdery bits and pieces of chunkasaur, as well as some tiny amounts of croc, fish, and bird material, so the excursion was quite informative for me. Kris brought his old friend and hunting partner Joe, and the three of us were chatting it up the whole time - it was a morning well spent. Before the day became too hot, we turned back and Kris offered to take me to a cenomanian Eagle Ford site in the area. I have a very hard time running into the lower Eagle Ford, so I was happy to accept, and we hit the creek with the sun high above. Now, you won't catch him tooting his own horn, so I'll do it for him - Kris is an insanely skilled collector. He and Joe have made some bonkers discoveries that I had no clue about - new things, completely articulated things... his 40 years of collecting experience has a track record that shines. In our first ten minutes into the creek, something coming out of the weathered bank caught my eye: 10 minutes prior, as we were walking in, I joked to Kris about finding a fully articulated Coniasaurus here. Coniasaurs have been bouncing in my head for a couple months now, ever since having an energizing discussion about them with Mike at SMU (the first time I found out they even exist). They and Pseudomegachasma were why I was so bent on finding cenomanian Eagle Ford, and this being my first time In cenomanian eagle ford strata, I had my fingers crossed.... and it seemed to work! I didn't want to be the boy who cried coniasaur... but I was fairly positive that that's what I was seeing. Kris was right behind me and seemed to agree - so, I drove a pick in below the vert to pry it out... and out came another vert locked into attachment with it, freshly broken in half. Silence. I looked at Kris, Kris looked at the vert, and we both went "oh!" From this alone, I was starting to get very excited, though I had to remind my self that odds were low that it would be all I was imagining. Kris (thank god he was there and could take over the digging, literally the best person for the job) began exploring deeper, and the vertebrae continued. Joe continued a little further up as we dug. Soon, we had a line of them exposed. Keep in mind, this is without 1.5 verts that broke off with the initial discovery: If you look to the left of the closest to the screen vert, you can see a tiny rib piece (which I originally assumed to be a process) The verts continued still, and then my phone overheated, so the pictures had to stop. Here's one that Joe nabbed of the scene: Paraloid was slapped on and Kris removed the first major block. A spot of bone on the other end looked to be on the side, so we moved in further and revealed another block where the bone seemed to finally stop. Covered in sweat we then continued our hunt. While looking at a pyrite inclusion, I practically stepped on a Xiphactinus tooth. Kris spotted it as I walked away, I was shocked I missed it! This sort of find is almost casual for these two (yeah, they're good), so he offered I keep it. I was happy to accept - it's the best Xiphactinus tooth I've personally seen. Our walk was mostly uneventful from there, right until we got to our turn around point. Kris and I realized at some point that we left Joe where we had turned around, and I went back to check on him. He was under a large overhang, where he had pulled out few plates of shale containing bone. Since both of them have found many large fish on this creek, they didn't bat an eye, but I was amazed! It seemed there were some skull elements of a large fish on them. "Are there more? " I asked "A little", said Joe, and he showed me where he spotted them. After a few seconds of moving material, we revealed another large piece of bone, and I about died. However, not too keen to excavate, considering it's fairly insignificant material for them (and the heat was oppressive at this point), we left for Kris's place. I told them I planned to get right back as soon as I got in my car, and they wished me luck and told me to send updates. Back at the site, I revealed the bone quickly, and in doing so, more bone that was previously buried revealed itself 10 inches to the left. I began on that, and soon realized I was working on a HUGE vert. "Xiphactinus it is then", I said, as nothing else from this portion of the cenomanian (except perhaps plesiosaurs) could produce something this big. As I continued work though, I started losing faith in my ID. The bone itself was nothing like fish. The day was drawing to a close, and I drove back home with a renewed interest in the mystery vert. I arrived home late. Then, early the next morning, I woke to do it all again, but first on the list was to drop off the coniasaur at SMU. I mentally prepared myself to spend another $90 on gas and then set out loaded with energy. I stayed at SMU for several hours - it's always a pleasure to spend time there so I didn't mind getting out to the dig site later than expected. It didn't take long for me to finally remove the vert... and revealed behind it was another...yes!! Happy to finally be out from under that overhang, I looked hard at what was in my hands. Both sides were revealed now, and I caught my breath. This was certainly reptile. I showed some photos to Mike at SMU, wondering about Plesiosaur, and he decided that while it would need some prep first, he doesn't think so. This leaves Archosaur origin, if I dare suggest. Some more field photos are below: (During the dig) Once removed: Unbelievable two days, to say the least. I'll have to return this weekend, and I'll update this thread as necessary. The site though is in the worst possible place it could be - at the back of an overhang held together by only the roots of a cedar, whose exposed roots hang like a curtain behind you as you work. It's going to take some work to make that safe, and more work to dive in from there, but I'm rearing to go. What a weekend - if I wasn't typing this at midnight I'd probably write much more, but that's the gist of it for now. Stay tuned! Update #1 I type this with dirt under my nails and a keen soreness in muscles I didn't know existed The original plan was to drive up with James ( @Rat Muncher ), a rock climbing friend who is getting interested into paleo lately, and my step brother Christian, who historically is always good luck. From there we were to meet with Joe, who originally found the fish bones to the right of the vert(s). Unfortunately Christian couldn't make it so it was James and I taking on the overhang all of Saturday, while Joe came and helped us today: We moved an enormous quantity of material. I can't really quantify it in weight, but it's like someone piled the back of their pick up high and then dumped it all in the creek. Some photos: How the site looked on arrival - I'm crouched in there for context: The first vert's original positioning (the one removed last weekend) The current vert, which lay directly behind the one above. The first vert was touching it at the bottom of the face, where you can see a break in the photo. As you can see- almost articulated. Look to the upper left of my finger: That's more delicate bone that's associated. This made things much more difficult - though the preservation of smaller skeletal elements hopefully suggests good preservation of the rest of the specimen. But now, instead of moving verts out one at a time, this was a game of getting the largest bone blocks out as slabs as possible, to preserve the orientation of these other bones. This is the practically the most difficult possible scenario for an excavation. As excited as I am, I have to admit I'm a little frustrated. The overburden here is ridiculous. We successfully made it safer, but it's not safe yet - and this animal is going straight into the bank. All three of the possible options (pliosaur, croc, or floated dinosaur) are lengthy animals. James and I slammed away with pick axes all of Saturday, and Sunday was more picking followed by the more concentrated work trying to remove the rock directly above the would-be bone block away, so that we can have room to pry up the bone block from the bottom. We thankfully accomplished this. Yet, we left the bone until next time - I don't want to fall victim to impatience and damage the bone with hand tools. The next time I come out again (hopefully soon), we'll remove the bone block we revealed with a chainsaw. Joe came in clutch here today - James and I were cloudy headed and sweating pure Red Bull by this point, and Joe pointed out some tricks to make our dig a little easier, some of which were obvious in retrospect - we made some goofy mistakes in that heat Once the bone block is removed, I have to admit I don't know what I'll do to get the rest of the bone out that may be behind it. I suspect it's going to be a story of getting little blocks removed at a time as we tediously tunnel in over the coming weeks, if the bone continues. If the bone getting revealed is exciting enough to convince them, I think I'll ask a paleontologist interested in this fauna to send some manpower and tools to continue. I would like to do research on this specimen if it gets there, so that would be great if it happens that way. Update #2: This is a delayed update...but I found more of the animal Joe came out with the chainsaw and it was a game changer - one entire day was spent removing overburden and chainsawing the sides of the bone block - we had trouble freeing the back end of the block so that's what I spent the next day doing when I was on my own. The block didn't break perfectly, but nonetheless a huge section came off, revealing one of the most beautiful sights I've personally laid eyes on: Three associated verts, with their fallen (unfused) neural arches, from right behind where the fourth vert was removed.... I lost my head, as this preservation means we may have much more of the animal waiting. There is more bone still in the bank- another process from another vert hiding away. Now, the folks at SMU have a hunch about what plesiosaur this is, as well as a few other exciting details (like how, for example, this animal seems to be facing into the bank) but I can't give y'all anymore hints - don't want to spoil any surprises!

What genus or species is this? Any ideas? I found this small jaw fragment (triangular form - first 5 pics) in the Lower South Bosque Member (Lower Turonian) of Eagle Ford Shale here in Travis County today. I see 7 spots for teeth of which all but one are significantly damaged or worn down. The size is 17mm x 20mm and 10mm tall including jaw. These are the best images I can get with my cell phone. I have found individual 5 to 7 mm tall teeth in this layer also that might fit in this jaw. Could it be a fish instead? Maybe Enchodus? I've also found a pycnodont (last three pics) fish jaw in this layer - slightly smaller sized.

I was responding to a post on TFF on FB about a vertebra someone had found at Post Oak Creek in Texas. I thought it was a snake vertebra since I have found several as I have hunted shark teeth there for several years. I went through my box of snake vertebra to take a picture to compare. As I pulled them out and lined them up, one vert did not line up at all and is clearly fossilized and is very similar to the one he posted that was identified as possibly being Coniasaur. Can anyone tell if that it truly what I have here or something else.