What the heck is this

[kodpkd]

I found this just N of Cass Colorado next to I-25 yesterday.  I have checked online and can't find anything like it. Animal or vegetable.  It is solid stone.

Edited October 5, 2021 by kodpkd
Clarification

[Tidgy's Dad]

A ferrous concretion. 

Maybe haematite. 

[Fossildude19]

Concretion

[Denis Arcand]

I think i see brachiopod on the lower left corner, not sure the picture is not very clear?

 

[val horn]

Is it man made  something plastic or epoxy resin to plug a pipe 

[Coco]

OK with what was said above.

 

In addition to the origin and age of the terrain in which the fossils are found, size is also important for proper identification. I invite you to read my last link in my signature. If you don’t have a rule, print the document I made available and put your fossils on it before making your photos, making sure to leave a box with the apparent size (pedagogical message)

 

Coco

[Rockwood]

9 hours ago, val horn said:

Is it man made  something plastic or epoxy resin to plug a pipe 

I think it might have been that, only a job that Ma nature did herself. A natural vent plug seems more like it to me.