All Echinoids have spines attached to their exterior skeletons for protection or mobility. Often they are separated from the body after death but occasionally fossils can be found with the spines still articulated with the body. The plate below features such fossils with Acrosalenia hemicidaroides Echinoids and their spines preserved together.
Here is a single Acrosalenia hemicidaroides that is preserved with some Brachiopods. Note that there are spines present in the matrix around the Echinoid but that none are in life position like the above specimen.
These specimens come from Landville, France and are Jurassic (Bajocian) in age.