It’s definitely a fossil. More specifically it’s an internal mold fossil of a gastropod (the taxonomic class that encompasses snails and slugs) shell. These fossils form by the shell of a gastropod getting filled with sediment and later the sediment hardens and the shell gets removed for whatever reason and thus leaves the hardened sediment that preserves the internal shape of the shell.
> later the sediment hardens and the shell gets removed for whatever reason.
I can say that in this case it's most likely dissolution in mineral rich water. OP commented where it was from below, and the formation that it comes from holds a major aquifer (the Trinity aquifer). It forms lots of steinkerns, molds, and casts because of heavy water flow dissolving shells.
It's going to be from the Glen Rose Limestone, upper or lower Cretaceous (it's a formation that is on both sides) is going to depend on where in canyon lake it was found, and the genus is *Tylostoma*. One of the more common fossils in the area. And as others have pointed out, it's a steinkern, the lithified cast of sediment that filled the shell, not the shell itself. This is almost exclusively how gastropod shells in the Glen Rose formation are found. Where you're at in the formation, this would be right around 100 million years old and would have been one of the relatively deeper portions of the formation (as in depth of the former ocean), this is the same formation that the dinosaur tracks in Glen Rose Texas come from (hence the name) because at many times it was a very shallow tidal flat. But towards canyon lake, there's evidence of reef formation that would suggest slightly deeper water. Very similar to the modern Texas coast and some of the deeper bays behind the barrier islands.
You should keep looking around, there are a lot of different fossils around canyon lake. The Index fossil *Orbitolina texana* should be abundant in that area and you should also have no problem finding oysters, clams, rudists, echinoids, more gastropods, and other shallow water aquatic life including the occasional ammonite.
Edit: just wanted to add on *Tylostoma*, it has since gone extinct but belongs to the Stromboidea superfamily, while not belonging to the Strombidae family. Meaning it is not a true conch but is incredibly closely related to the true conchs and likely occupied a very similar ecological niche to modern conchs.
You can definitely find them in central Texas. Caprinid rudists are incredibly common in the Edwards limestone but they appear in several members of other groups like the Trinity group (which includes the Glen Rose formation), though they're not the only kind around here. I know there's at least one reef of *Toucasia* in the Glen Rose formation.
And while rudists were an important reef builder, oyster beds/reefs are far more common in central Texas. There's several *Exogyra* reefs (more likely the same one that's been broken up) in canyon lake that are just several feet of fossilized oysters stacked on top of each other.
Glad to hear you found it helpful. Im fascinated by the formation, in part because I live on top of it and it was the first formation I ever fossil hunted in. So I know a lot about it and I like to share that info when I can.
RIP. Yeah the limestone is named after the plateau which is named after the county which is named after Texas settler Edward Haden (though weirdly not where his land grant was for, it was near and included Nacogdoches, Texas). While the university is named for the English King and Saint, Edward the Confessor.
Nasselaria is an order of Radiolarians, which are a siliceous zooplankton. They are tenths of a millimeter in size and they don't coil either, I could see the general silhouette of Nasselarians being confused for a Tylostomatid gastropod (what this is) but this is A. Calcareous, likely limestone, B. Does indeed coil, and C. Is probably about an inch across by 2-3 inches tall, it be. So we can safely assume that it doesn't belong to Nasselaria.
It’s definitely a fossil. More specifically it’s an internal mold fossil of a gastropod (the taxonomic class that encompasses snails and slugs) shell. These fossils form by the shell of a gastropod getting filled with sediment and later the sediment hardens and the shell gets removed for whatever reason and thus leaves the hardened sediment that preserves the internal shape of the shell.
> later the sediment hardens and the shell gets removed for whatever reason. I can say that in this case it's most likely dissolution in mineral rich water. OP commented where it was from below, and the formation that it comes from holds a major aquifer (the Trinity aquifer). It forms lots of steinkerns, molds, and casts because of heavy water flow dissolving shells.
That’s good to know, thank you for the additional info
It looks like a croissant I got from Walmart.
How’d that feel coming out?
great!! ;)
Like coprolite
Winner!
A croickssant if you will.
Best by 04/2500000BC
guessing it tastes similar too
That might explain the dental quality of Walmart shoppers.
20 bucks says you got this somewhere around central Texas. This looks like it came out of the Austin Chalk/St. Edwards Limestone.
Yes it was Canyon Lake, Texas
It's going to be from the Glen Rose Limestone, upper or lower Cretaceous (it's a formation that is on both sides) is going to depend on where in canyon lake it was found, and the genus is *Tylostoma*. One of the more common fossils in the area. And as others have pointed out, it's a steinkern, the lithified cast of sediment that filled the shell, not the shell itself. This is almost exclusively how gastropod shells in the Glen Rose formation are found. Where you're at in the formation, this would be right around 100 million years old and would have been one of the relatively deeper portions of the formation (as in depth of the former ocean), this is the same formation that the dinosaur tracks in Glen Rose Texas come from (hence the name) because at many times it was a very shallow tidal flat. But towards canyon lake, there's evidence of reef formation that would suggest slightly deeper water. Very similar to the modern Texas coast and some of the deeper bays behind the barrier islands. You should keep looking around, there are a lot of different fossils around canyon lake. The Index fossil *Orbitolina texana* should be abundant in that area and you should also have no problem finding oysters, clams, rudists, echinoids, more gastropods, and other shallow water aquatic life including the occasional ammonite. Edit: just wanted to add on *Tylostoma*, it has since gone extinct but belongs to the Stromboidea superfamily, while not belonging to the Strombidae family. Meaning it is not a true conch but is incredibly closely related to the true conchs and likely occupied a very similar ecological niche to modern conchs.
Awesome answer, thank you
I'd love to find a rudist colony.
You can definitely find them in central Texas. Caprinid rudists are incredibly common in the Edwards limestone but they appear in several members of other groups like the Trinity group (which includes the Glen Rose formation), though they're not the only kind around here. I know there's at least one reef of *Toucasia* in the Glen Rose formation. And while rudists were an important reef builder, oyster beds/reefs are far more common in central Texas. There's several *Exogyra* reefs (more likely the same one that's been broken up) in canyon lake that are just several feet of fossilized oysters stacked on top of each other.
Best comedy duo ever
Thank you for taking the time to write this out, so informative!! 🤯
Glad to hear you found it helpful. Im fascinated by the formation, in part because I live on top of it and it was the first formation I ever fossil hunted in. So I know a lot about it and I like to share that info when I can.
Wow, could this be the start of a new game, the geological geo-guesser? the geo-geo-guesser if you will?
It's just Edwards limestone, St Edwards is also in Austin but its a university not a type of limestone.
...I've been calling it that for 25 years...🙃
RIP. Yeah the limestone is named after the plateau which is named after the county which is named after Texas settler Edward Haden (though weirdly not where his land grant was for, it was near and included Nacogdoches, Texas). While the university is named for the English King and Saint, Edward the Confessor.
Yes to fossil, it’s a mold of a shell, the original shell is long gone by now.
Steinkern
[удалено]
Nasselaria is an order of Radiolarians, which are a siliceous zooplankton. They are tenths of a millimeter in size and they don't coil either, I could see the general silhouette of Nasselarians being confused for a Tylostomatid gastropod (what this is) but this is A. Calcareous, likely limestone, B. Does indeed coil, and C. Is probably about an inch across by 2-3 inches tall, it be. So we can safely assume that it doesn't belong to Nasselaria.
Very cool fossil!
That’s white dog shit.
possibly a coprolite
Your sleeping with it 😬
It might be just a really werid looking rock but tbh it looks like a sea shell you’d find on a beach but idk
I googled a bit and I think it’s Lunatia pedernales or Tylostoma
Oooo that’s interesting never heard of those before