My 7 year old son found this fossil whilst cracking open flint in Deal, Kent. The fossil (assuming it is) looks like scales/cells/shell and is chalky. The oblong lines are raised and well defined and tough to the touch. It certainly looks like a natural biological pattern. It looks very a little smaller than a golf ball stuck in the flint. Its edges disappear under the flint with the appearance that it is a sphere. Be glad if anyone has an idea. Thanks[![enter image description here]]
That is a sea urchin (echinoid) or at least part of one. the pattern of plates is fairly distinctive. 2 rows of small plates alternating with 2 rows of large plates. I am not familiar enough with urchin phylogeny to give you species but you might be able ot get it from the biology stack.