Endoskeleton
Echinoderms are a phylum with usually 5 fold symmetry, spines and calcium carbonate plates.
Hardened plates of calcium carbonate form its endoskeleton.
Ambulacral plates are part of the skeletal system of echinoderms, such as sea urchins and sea stars. They are calcium carbonate plates that make up the tube feet and spines used for movement and protection. These plates are arranged in distinct patterns on the body surface of echinoderms.
Echinoderms have an Endoskeleton made up of 95 % calcium carbonate.
YES, but it is not the same "ossicles" that are found in the mammal ear. Echinoderm ossicles are small calcium-matrix plates that make up the dermis or endoskeleton of the echinoderm. They provide protection and support to the underlying tissue.
In echinoderms, the test refers to the hard calcium carbonate skeleton that provides structure and support to the organism. It is composed of plates called ossicles, which are often covered by a thin layer of skin. The test is a defining characteristic of echinoderms and contributes to their ability to withstand pressure in their marine habitats.
Calcium carbonate
Ossicles
Ossicles
Ossicles
The first organisms to develop a hardened endoskeleton were likely ancient invertebrates called echinoderms, such as sea urchins and starfish. Their endoskeleton is made of plates composed primarily of calcium carbonate. This adaptation provided structural support and protection as these organisms evolved to live in various marine environments.
Echinoderms such as starfish and similar marine animals with radially symmetrical bodies have bone-like calcareous skeletal plates in their skin