These include crabs, molluscs, sea urchins, starfish and polychaete worms. Starfish are abundant, as are sea urchins and limpets. Starfish, sea urchins, and sea anemones are also present. The seabed abounds in sponges, shellfish, sea urchins, crustaceans, fish etc. Commercially harvested echinoderms include sea cucumbers and sea urchins. Sea otters are hunters of clams, sea urchins and other shelled creatures. Sea otters eat shellfish and other invertebrates (especially clams, abalone, and sea urchins). Globotruncanid Foraminifera and echinoderms such as sea urchins and starfish (sea stars) thrived. Echinoderms are exclusively marine and include starfish, sea urchins, and sea cucumbers. The strata contain fossil corals, crinoids, sea urchins and ammonites. Mollusks, worms, sea urchins, and small fish are also taken. It feeds on hard-shelled mollusks, crustaceans, sea urchins, and fish. Fivefold symmetry is found in the echinoderms, including starfish, sea urchins, and sea lilies. Some sea urchins and clams can burrow into rock. Octopus, sea urchins and mussels feature heavily.