What do I have?

[MaadMatt556]

I dug this out of a creek bed in eastern Iowa about 9 years ago. I saw the top sticking out of the dirt. The creek bed was probably 20' down +/- a few feet. It was near another rock I dug out the same day that was just a 20lb rock of quartz. There's a couple spots that chipped off showing the white inside making me think it's just quartz. But the shape of it looks like a mushroomed bullet like it impacted the ground. I don't know a lot about how rocks are formed but I don't think quartz is ever pliable enough to form the way this thing did. 

    A friend of mine saw it the other day and got really excited. He asked where I got the dinosaur vertebrae. I never thought about it being a vertebrae till then. When I Googled a dinosaur vertebrae it looks like it could be. I just hope I haven't been keeping a 30lb petrified turd in my living room for 9+ years. So if anyone has any ideas on what I have please feel free to let me know.

[Fossildude19]

No bone texture. No vertebra morphology.  Not a dinosaur bone.

This looks like a stromatoporoid, sponge, or bryozoan colony, to me. 

 

What county was it found in?

Washington is in Washington County, which exposes bedrock from the Devonian, Mississippian, and Pennsylvanian eras.

Here is a geologic map, showing that Eastern Iowa doesn't have rocks young enough to have dinosaur remains.

 

[MaadMatt556]

It was in Washington, Iowa off Coppick Rd. I thought it looked kind of like a coral or sponge.

So do you think it's worth anything or do I have a 30lb door stop.

[Fin Lover]

We don't discuss monetary value or cost on the forum.  Other members can tell you if a particular fossil is common vs. rare, good vs. poor quality, etc., but not whether it's "worth" anything.  Worth is often in the eye of the beholder, anyways...if you like it and have room to keep it, then it's worth keeping. 

[Ludwigia]

I'd say that you have an interesting discussion piece which could also be used as a doorstop if you like.

[Tidgy's Dad]

I would tentatively suggest sponge and advise doing some research as this could be a rather nice piece,

[trilobites_are_awesome]

Again that is a geode Just search Iowa geode you will find ones like that one (IF you crack it open you can find crystals) . Nice find

Edited November 1, 2023 by trilobites_are_awesome

[MaadMatt556]

I'm sure it's not a geode cause it has imprints of soft tissue or coral like texture. The more I research it I'm finding pictures of fossilized sponges that look very similar. I have a bunch of geodes some broken open and some whole. I don't want to break it and ruin it's value.