A spiny skinned invertebrate is called a sand dollar. That is because they are are echinoderms (a type of invertebrate),
A spiny-skinned invertebrate that lives on the ocean bottom floor is called a sea urchin.
Echinoderms
Echinoderm
Echinoderms
Sea urchin
No, while crabs are indeed invertebrates thy have a carapace not a skin.
Hedgehog or porcupine
their spiny skin
A sea cucumber is a soft-bodied animal, not a spiny-skinned animal.
no
Echinoderm is the scientific name for spiny-skinned animals. Spiny-skinned animals include sea urchins, sand dollars, brittle stars, starfish, and sea cucumbers.
Starfish