Findables

The bullet-shaped 'pencils' you find in Cretaceous creek gravel are belemnite rostra — the internal hard part of an extinct squid relative. They were the dominant shelled cephalopods of Mesozoic seas before ammonites took over. Easy first find for kids.

Fossilized poop. Less glamorous than teeth but tells us what predators were eating — coprolites often contain shark scales, fish bones, and shell fragments. Common in phosphate spoil piles and Aurora-area gravel.

Cetacean bone is the heaviest, densest non-tooth find on a typical hunt. Vertebrae are the most recognizable — round centra with the neural arch usually broken off. Ear bones (tympanic bullae) are the prize: dense, fist-sized, shaped like a cooked clam.

Tiny droplets and chips of fossil tree resin from the Raritan Formation occasionally wash into Big Brook and a few other NJ creeks. Many contain microscopic insects. Genuine NJ amber is rare enough that most people hunt a lifetime without finding a piece — bag it carefully.

Bright brassy cubes and clusters that fooled prospectors for centuries. In creek gravel it forms when iron-rich groundwater meets the sulfur left behind by decaying organic matter — which is why pyrite often replaces fossils, preserving belemnites and shells in metallic gold.

Coiled cephalopods that ruled Mesozoic seas alongside the dinosaurs and went extinct with them at the K-Pg boundary 66 million years ago. Complete specimens are rare; most NJ creek finds are fragments of the iridescent inner-shell layer or impressions of the suture pattern in chalk matrix.

Thick, gnarled oyster shells (typically Exogyra and Pycnodonte) that paved the floor of the Late Cretaceous seaway. Their durable calcite preserves them better than almost any other invertebrate — you'll find them in nearly every Cretaceous creek bed on the East Coast.

Fossil sand dollars and sea biscuits — the calcified skeletons (tests) of extinct echinoids. The five-petal flower pattern on the top side is unmistakable. Eocene through Pliocene worldwide; the Florida Tampa Member produces gorgeous flat Scutella by the bagful.

Modern, not fossil — but a steady consolation prize on tooth hunts and a kid's gateway drug to beachcombing. Decades of tumbling in surf gravel produces frosted edges and a soft satin finish. Brown, green, and clear are most common; cobalt blue and red are jackpot rare.