ⓘ Ossicle (echinoderm)

                                     

ⓘ Ossicle (echinoderm)

Ossicles are small calcareous elements embedded in the dermis of the body wall of echinoderms. They form part of the endoskeleton and provide rigidity and protection. They are found in different forms and arrangements in sea urchins, starfish, brittle stars, sea cucumbers, and crinoids. The ossicles and spines are the only parts of the animal likely to be fossilized after an echinoderm dies.

                                     
  • endoskeleton consisting of ossicles connected by a mesh of collagen fibres. A 2014 analysis of 219 genes from all classes of echinoderms gives the following
  • Astropecten and Goniaster that immerse themselves in sediment. They are ossicles composed of calcite microcrystals found on the aboral upper surface of
  • of the Echinoderm taxa, five arms extending from a central disc. The arms branch off into smaller and smaller subdivisions. The calcified ossicle endoskeleton
  • asymmetrical and consists of five arms attached to five radial ossicles The arms subdivide at arm ossicle I or II. The World Register of Marine Species includes
  • five double rows. The cuticle is leathery, stiffened by numerous smooth ossicles small irregular perforated plates which form part of the body wall. The
  • homologous with the body or disc of other echinoderms The base of the theca is formed from a cup - shaped set of ossicles bony plates the calyx, while the
  • echinoderms sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles or
  • Echinodermata or class Asteroidea and Edrioasteroidea. Echinoderms can have ambulacral parts that include ossicles plates, spines, and suckers. For example, sea
  • ossicles which are generally wheel - shaped with 8 or more spokes. They are abyssal sea cucumbers, and may be the deepest - living group of echinoderms :