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Showing results for tags 'ophiura'.
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From the album: Texas Cretaceous Fossils: Starfish and Crinoids
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- cretaceous
- del rio formation
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From the album: Texas Cretaceous Fossils: Starfish and Crinoids
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- cretaceous
- del rio formation
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(and 3 more)
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From the album: Pawpaw Formation
Ophiura sp., Tarrant Co. Albian, Cretaceous Dec, 2022 - Jan, 2023-
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- brittle sea star
- ophiura
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Articulated Brittle Sea Star and The First Fossil That Looked Back at Me! Pawpaw Formation
Mikrogeophagus posted a topic in Fossil Hunting Trips
The brief visit to the second half of the Pawpaw exposure turned out to be a huge success. I didn't think it was possible, but the finds got even better! There wasn't much of a story to be had with accessing the site, so I'll keep things brief and jump straight into the finds. Once I relocated the productive greyish layer, I was already gathering various claw bits left and right. Their bright white coloration really makes them pop out from the ground. However, I didn't let this lead me into lowering the thoroughness of my search. I still took a close look at every pebble and under every rock. The fruit of my labors came when I locked onto the first shark tooth for the site, a small Leptostyrax macrorhiza. I've found one in the past in the Duck Creek, but never in the Pawpaw. Nine times out of ten I would have missed this guy. Just look at how hidden he is in this photo: Leptostyrax macrorhiza hidden beneath a couple pebbles The vertebrate finds continued with a tiny ~1 cm fish jaw fragment. Let me know if you recognize it: Close up with my new stereo microscope! Not too long after, the crustacean finds began to ramp up. Scattered about were fragments of carapaces. It was only a matter of time before the first complete carapace of the day was found. Steorrosia aspera I want to say I continued finding several more that weren't impressive in situ, but amazing after cleaning. One Steorrosia sp. was pretty banged up on the sides, so I couldn't confidently pin an ID. However, I noticed that it had little black dots where the eyes are usually missing in these crab fossils. Well, my Christmas gift came right on time! I placed it under the digital microscope and almost fell out of my chair. This little crab had preserved compound eyes. I'm not sure how rare such a feature is, but it impressed the hell out of me. I should warn that the pics aren't terribly clear since taking photos requires me to press a button on the microscope that shakes the whole thing. Plus, viewing something so small had the device at its absolute maximum magnification. Hopefully you all can spot the pattern on the compound eyes. Underside of the Steorrosia sp. The face of the Steorrosia sp. A close up of one compound eye. Those faint circles are what I interpret to be the individual eyes. Although not from the grey layer I was hunting in, pyritic cephalopods could be found washed out from the red sandstone above. Most are pretty beat up, but I make sure to collect a little bit of each species I can find. I have enough Engonoceras serpintinum as it stands, but I can't help taking a picture when I find a nice one. Engonoceras serpintinum Mantelliceras sp. The first unorthodox find of the day was very clearly a tiny brittle sea star leg. I've always wanted to find starfish parts, so I was super excited to pick this specimen up.... little did I know. Not sure if it possible to ID beyond genus from just a leg segment: Ophiura sp. in situ Close up of same leg From there, I found a couple more very nice carapaces including a MUCH more complete Texicancer renfroae?. Face of the Texicancer renfroae? I hate to say I may have already found a Feldmannia wintoni that surpasses the one I submitted to FotM I need to figure out how to turn off that pesky time stamp on the bottom right. Starting to feel like I'm taking crab mugshots When I got home, I was able to clean up and analyze a couple of enigmatic specimens that had initially given me starfish vibes. After a bit of research, I believe my hunch was right. These two specimens each have one side covered in "spikes". I found a paper (Blake and Reid 1998) on Pawpaw starfish that had similar structures on the oral sides of the arms. Betelgeusia reidi (cool genus name btw) seemed the closest match, but it's a tough call. And to round it off with one of the most legendary finds in my fossil hunting career, a mess of associated brittle sea star chunks including the central disc and several arms fragments. I tried to find more, but these were the only pieces I came up with. It was a massive pain paraloiding this thing together I must admit. There's not much surface area to work with, but it eventually came it alright. Actually looking at it again, I think I put the short arm on upside down, but that will be a headache for another day... The only local brittle star species I know from this period would be Ophiura graysonensis and O. texana. Hard for me to say which it resembles more closely, but I'm leaning towards graysonensis, assuming those exist beyond just the Grayson Marl. The central disc and a couple of arm bits in situ Oral side? Aboral side? It's safe to say this is my most productive hunt yet! Hopefully you all enjoyed reading through this little report. Here is an overview of the finds: Fish jaw section, Leptostyrax macrorhiza, and xiphactinus? tooth fragment (was hoping it was pterosaur ) Crabs of the day L to R: Various Steorrosia, Feldmannia wintoni, Texicancer renfroae?, and Steorrosia reidi? Top: Engonoceras serpintinum Bottom L to R: Mantelliceras sp., Mariella worthensis, Scaphites hilli, and Baculites comanchesnis? Ophiura sp. arm fragment, chunks of Betegeusia reidi?, and a couple of bivalves Thanks for reading!- 16 replies
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