Hi @giovany-figueroa! I can see why you think this might be a fossil. However, I think it’s either a fracturing or chemical weathering pattern. These sorts of rocks are notorious for that. (@jbauer)

Hi, @giovany-figueroa – that radiating pattern is certainly striking but I am not sure if it is a fossil or not. I’m going to tag in @mackenzie-smith who has a wide range of knowledge and knows much more about the Cenozoic than I do.

https://macrostrat.org/map/#/z=10.8/x=-66.5239/y=18.0282/bedrock/lines/ suggests Ponce is Miocene – Oligocene in age.

Hi @Giovany-Figueroa! If you know where this was found, you can use https://macrostrat.org to figure out what age it is! This looks almost like the outside of an ammonite. More photos of different angles, and using a scale in your photos would be very useful