Poor "cast"? of something found in central texas

[AJinTexas]

Greetings, this is my first post on this forum!  I can typically identify most of my finds using google, but I found an interesting / poorly formed cast, or maybe concretion?, in a shape I hadn't seen before and I have no idea what it is or how to potentially clean it.  It seems pretty fragile, and with no idea what I am looking at, I haven't attempted any cleaning.  Hoping to find some ideas here!

 

Found in Hays county, TX, presumably part of the Glen rose limestone formation.  Came out of a small cliff made from an old small quarry dug out of the side of a hilltop.  The limestone it came out of is yellow / gray and crumbles easily, it frequently breaks apart to reveal poorly formed "clam" cast clusters (the entire hilltop is basically an ancient 'oyster' bed), periodically produces some nice specimens though!  Could have come out anywhere from ~5-12 feet (~1.5-3m) beneath the cliff face (I am presuming in the lower range since it was still intact, a higher fall may have split it).

 

Crab? Coral? Cluster of 'clams'? Stingray??  Lol, I am utterly stumped on this one.

 

If I left out any useful information or if any more photos are desired, just ask and I'll do my best to provide it!

 

Thanks!

[Sandfossil]

I am not an expert at all but I have something like them I believe them to be a trace fossil. A burrow for a worm. I have all different sizes and shapes if thats what it is. Conostichus, they have a pretty shady history in my opinion. I think the worms do an outstanding job at building to last millions of years and hold up pretty good in my opinion. I really like them. 

Now to hear from the experts about what it is. 

 

[ClearLake]

I don’t think you will have any idea of what it is until you clean it at least enough to see what’s under the mud. Right now it’s a clump of muddy rock. Might be something, might be nothing. 

[JohnJ]

Welcome, AJ.  I've seen many of these concretions in the lower Glen Rose Formation.  They can vary in size...'marbles' to 'grapefruit'.

 

@erose

[AJinTexas]

12 hours ago, JohnJ said:

Welcome, AJ.  I've seen many of these concretions in the lower Glen Rose Formation.  They can vary in size...'marbles' to 'grapefruit'.

 

@erose

Neat!  Found anything interesting in them?

 

I am attempted to clean it slowly with a softer brush, most of the outer gravel came out pretty easily and I started damping it softly with a sponge/water.  I've found several small clam forms and what might be a small piece of coral?  But it could be a root that wormed in as it was towards the outside just underneath some of the loose gravel, its very small but feels hard.  It looks like there might be something appearing in the middle, and the gray material in the left of the photo has some sort of form to it...  But I'm still clueless

 

@SandFossil, that is interesting, the outer shape certainly shares some similarities to what I have!

[JohnJ]

I have yet to find any identifiable fossils in them.  Soak the stick-like object in water to see if it becomes pliable.  An old toothbrush could help clean it up better.

[AJinTexas]

Removed all (most) of the silt!  Revealed some pretty neat quartz on whatever it is.  Am I crazy for seeing some sort of crushed carapace?  I don't know if it can be identified as anything, but neat and fun for me to clean out as it was the first fossil like this I have found.  The stick turned out to be a stick.

 

Any thoughts or ideas what this could be?

[JohnJ]

It is a geologic concretion, not a crushed carapace.  The gypsum, or calcite, crystals can create a differential hardness in the matrix.

[AJinTexas]

Definitely.  This is the first one I'm cleaning, and pretty much have no idea what I am looking at overall with the matrix.  Not quite sure what to remove and kind of wondering if I should maybe crack the top off etc.  I'll probably stare at it for a while and maybe make a post in the preparation forum.  Might set it aside and practice on some other stuff

[erose]

I know these well. They are always concretions and I as well have never found anything inside them other that the occasional crystals of calcite, or maybe gypsum.  If the stick-like thing proves to be fossil, it is probably a crab's leg.

 

 

[AJinTexas]

Unfortunately the stick was a stick, and unfortunately sounds like its just a concretion with crystals haha.

 

Live and learn, thanks for the input!

[erose]

10 minutes ago, AJinTexas said:

Unfortunately the stick was a stick, and unfortunately sounds like its just a concretion with crystals haha.

 

Live and learn, thanks for the input!

The thing to know about concretions is that they almost always form around "something". So it is always worthwhile to open them up and take a look. These ones that occur in the Glen Rose virtually never have anything recognizable inside.  In other locations and formations you may find something.

[AJinTexas]

13 minutes ago, erose said:

The thing to know about concretions is that they almost always form around "something". So it is always worthwhile to open them up and take a look. These ones that occur in the Glen Rose virtually never have anything recognizable inside.  In other locations and formations you may find something.

Good to know!  Ill probably work on it a little more for fun / practice.  Maybe I'll find treasure in the middle!!  It at least has some nice little crystals if nothing else