What Is a Sea Biscuit Fossil? Sea biscuits are ancient echinoids, distant cousins of modern sea urchins, and are sometimes confused with sand dollars. They are beachcombers’ treasures because of their unique star-shaped pattern and rock-hard texture. However, how can you determine if that seemingly innocuous rock is actually a fossil dating back 30 million years? Fossilized Sea Biscuit Think about the source of a rock that has patterns resembling stars. Is it a fossilized sea biscuit, perhaps? Explore the field of paleontology more thoroughly and share your discoveries with other enthusiasts. Observing Sea Biscuit Fossils Together, we will examine sea biscuit fossils from a group viewpoint. They are windows into Earth’s past, not just curious objects. Their fortitude, tenacity, and the tales they whisper will astound us.