What are these dotted ball shaped things I circled in yellow in the image?
I thought they may be sea urchin skeletons. Though the things in the image may be too many and too large?
They are in a mural in Brighton, England. The subject is "Protecting Costa Rican Wildlife", so I guess they are of some native species there.
Yes they look like sea urchin. However, the live ones look like the black shapes.
Not all urchins look like that, there's a lot of different types