Heliophora orbiculus, also known as West African Sand Dollars, are flat echinoids, (sea urchins) with very distinct finger like frills.
Their frills are ideal for burrowing and maintaining their position in the unstable sediment surfaces in which they live.
They are an example of a living fossil- a currently living species that also exists in the fossil record. This specimen is from the Pliocene, making it 2 to 5 million years old.
This species first appeared in the Late Miocene period beginning around 9 million years ago. As is typical with echinoids, they exhibit 5-fold symmetry which is visible in the star pattern on their surface.