Echinoderm | Definition, Characteristics, Species, & Facts | Britannica
Nov 14, 2024 — Although all living echinoderms have a pentamerous (five-part) radial symmetry, an internal skeleton, and a water-vascular system derived from the coelom (central cavity), …
Echinoderm - Radial Symmetry, Tube Feet, Spines | Britannica
Nov 14, 2024 — Living echinoderms have a conspicuous five-rayed, radial symmetry that masks their fundamental bilateral symmetry. The skeleton is dermal and each skeletal unit consists of …
Echinoderm - Evolution, Adaptations, Paleontology | Britannica
Nov 14, 2024 — echinoderms. Because the phylum Echinodermata was already well diversified by the Lower Cambrian Period, a considerable amount of Precambrian evolution must have taken …
Echinoderm - Radial Symmetry, Tube Feet, Water Vascular System …
Nov 14, 2024 — Echinoderm - Radial Symmetry, Tube Feet, Water Vascular System: The water vascular system is characteristic of echinoderms. Most have cilia on their outer body wall and …
Species and distribution of echinoderms | Britannica
echinoderm , Any of various marine invertebrates (phylum Echinodermata) characterized by a hard spiny covering, a calcite skeleton, and five-rayed radial body symmetry.
Echinoderm - Asexual Reproduction | Britannica
Nov 14, 2024 — The gastrula develops into a basic larval type called a dipleurula larva, characterized by bilateral symmetry; hence the name, which means “little two sides.” A single …
Echinoderm - Marine, Invertebrate, Diversity | Britannica
Nov 14, 2024 — Echinoderm - Marine, Invertebrate, Diversity: Diverse echinoderm faunas are found in all marine waters worldwide except the Arctic, where few species occur. When …
Echinoderm - Locomotion, Tube Feet, Water Vascular System
Nov 14, 2024 — Echinoderm - Locomotion, Tube Feet, Water Vascular System: Echinoderm locomotion includes the use of spines, tube feet, and arms; when overturned, they exhibit a …
Echinoderm - Adaptations, Diversity, Characteristics | Britannica
Nov 14, 2024 — Echinoderm - Adaptations, Diversity, Characteristics: Some scientists believe that the higher classification of the echinoderms should be based upon a study of the embryology …
List of echinoderms | Sea Stars, Sea Urchins, Sea Cucumbers
An echinoderm is any of a variety of invertebrate marine animals belonging to the phylum Echinodermata, characterized by a hard spiny covering or skin. This is a list of significant …