The first definitive echinoderms appeared near the start of the Cambrian. Echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so …

Echinoderm, any of a variety of invertebrate marine animals belonging to the phylum Echinodermata, characterized by a hard, spiny covering or skin. Living species include sea …

Together, these animals make up the Echinodermata, a word with Greek origins meaning “hedgehog skin.” Echinoderms live in every ocean, even off the coast of Antarctica. Well …

Jun 30, 2025 · Echinoderms are spiny-skinned invertebrates of the phylum Echinodermata, specifically recognized by the pentamerous body (five-pointed) symmetry in adults. The …

Dec 25, 2025 · Echinoderms are a diverse group of invertebrate marine animals that include starfish, sea urchins, sand dollars, sea cucumbers, and crinoids. The phylum contains about …

Echinoderms include several familiar organisms such as starfish (or sea stars), sea urchins, sand dollars, sea cucumbers, and brittle stars. These animals are found in oceans worldwide, from …

Whereas five major groups of echinoderms are living today (starfish, brittle stars, sea urchins, sea cucumbers, and sea lilies), more than 20 other, equally distinctive extinct echinoderms groups …

Echinodermata has approximately 7000 described living species and about 13,000 extinct species known from the fossil record. This phylum is the largest without any freshwater or terrestrial …

Sea stars (Figure 1), sea cucumbers, sea urchins, sand dollars, and brittle stars are all examples of echinoderms. To date, no freshwater or terrestrial echinoderms are known.

Aug 4, 2025 · Echinoderms are a group of marine invertebrates found across all the world’s oceans, from shallow coastal waters to the deepest abyssal plains. These organisms …