Cidaridae
Cidaridae is a family of sea urchins, commonly known as slate pencil urchins or pencil urchins. These echinoderms are distinguished by their exceptionally long, stout, and often brightly colored spines. Unlike many other sea urchin families where the spines are relatively short and thin, the spines of Cidaridae are thick and have a calcareous, porous structure, giving them a resemblance to pencils or chalk. The apical system, which includes the anus and madreporite, is typically large and prominent.
The family Cidaridae is diverse, with numerous genera and species found in marine environments worldwide, from