Table of Contents
What classifies an echinoderm?
An echinoderm is an organism (all marine) that has a spiny skin. Most echinoderms have pentamerous radial symmetry, meaning they can be divided externally into five equal parts along a central oral/aboral axis. Echinoderms also have a water vascular system.
What is the most ancient class of echinoderm?
Kingdon Animalia
| Phylum Echninodermata Taxonomy | |
|---|---|
| Subphylum | Class |
| Subphylum Blastozoa | Blastoidea (Cambrian to Permian) |
| Subphylum Asterozoa (starfish and kin, also called Stelleroidea) | Asteroidea (True starfish or sea stars – Lower Ordovician to recent) |
| Ophiuroidea (Brittle stars – Lower Ordovician to recent) |
What is an echinoderm quizlet?
Echinoderm. A slow-moving or sessile marine deuterostome with a water vascular system and, in larvae, bilateral symmetry. Echinoderms include sea stars, brittle stars, sea urchins, feather stars, and sea cucumbers.
What organism would be classified as an echinoderm?
Echinoderms (Phylum Echinodermata) are a phylum of marine animals. The adults are recognized easily by their (usually five-point) radial symmetry, and include such well-known animals as starfish , sea urchins, sand dollars, and sea cucumbers.
Which feature would you find in an echinoderm?
Echinoderms have these features: A skeleton of plates. These are formed from calcite, a mineral made of calcium carbonate. Five-rayed (pentameral) symmetry. A water-vascular system. This is an internal system of tubes and bladders filled with water. Tube feet. These are extensions of the water-vascular system. Stenohaline. Entirely marine.
What are the four major kinds of echinoderms?
Holothuroidea. More commonly known as Sea Cucumbers,these echinoderms have no arms on their bodies.
What are some unique characteristics of echinoderms?
Characteristics of Echinodermata They have a star-like appearance and are spherical or elongated. They are exclusively marine animals. The organisms are spiny-skinned. They exhibit organ level of organization. They are triploblastic and have a coelomic cavity. The skeleton is made up of calcium carbonate. They have an open circulatory system.