Good morning guys! I’ve recently been exploring the coast of North York and found ammonites in abundence I also split open a rock to reveal what appears to be a fish fin of some sorts can anyone clarify this for me!? It would be greatly appreciated! I’ll also post some pics of the anmonites found and if anyone knows what species they are could you inform me please! Thanks for your time! Also sorry about the poor lighting of the ammonite picture Hope they can still be made out.