Details: Sea Urchin are Echinoderms whose body is contained in a shell made up of numerous plates of the same shape. They appeared during the Ordovician period, about 500 million years ago, and are still present in seas all over he world. The star shaped patterns on the shell surface are due to many small holes from which projeced defensive spines to various shapes and sizes. Sea urchins are useful paleo-ecological indicators because by studying their shapes it is possible to trace back and identify the environment in which they lived.
- Box measure 1.5"x1.5"
- Stone measure approx. 1.5"