Sea Urchin chemistry Average weight is roughly 0

Average weight is roughly 0

A small information card is also included

The final impact emitted a booming explosion that was heard and felt for nearly 200 miles

Our target size is approximately 1x1 cm

Sea Urchin chemistry Average weight is roughly 0Above: Front of the Specimen Card Ancient sea urchins, small and spiny creatures, have existed for millennia. These echinoids first appeared in oceans 450 million years ago, where they fed on algae and sponges. Their flexible spines purpose was two fold: to protect against predators and allow for the slow crawl towards the urchins next meal. Buried for millions of years, their fossils appear in many places where those oceans once were and have