Sea urchin - Wikipedia
WEBSea urchins or urchins (/ ˈ ɜːr tʃ ɪ n z /) are typically spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to 5,000 metres (16,000 ft; 2,700 fathoms). [1]
Sea urchin | Description, Anatomy, & Facts | Britannica
WEBJul 31, 2024 · sea urchin, any of about 950 living species of spiny marine invertebrate animals (class Echinoidea, phylum Echinodermata) with a globular body and a radial arrangement of organs, shown by five bands of pores running from mouth to anus over the test (internal skeleton).
ADW: Echinoidea: INFORMATION
WEBEchinoidea. There are approximately 940 species of echinoids distributed worldwide in marine habitats from the intertidal to 5000 meters deep. Their fossil record is extensive due to their test (an internal skeleton), and dates back to the middle Ordovician period.
Echinoidea - Digital Atlas of Ancient Life
WEBMay 27, 2020 · Class Echinoidea Snapshot. Examples: sea urchins, sand dollars, sea biscuits, heart urchins; Ecology: marine, mobile carnivores, herbivores, deposit feeders; Key features of group: calcitic test, aristotle’s lantern, spines; Diversity: ~4,221 living sp., ~10,375 extinct sp. Fossil record: Ordovician to Recent
Echinoidea - Animalia
WEBClass. Echinoidea. 22 species. Sea urchins are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin are distributed on the seabeds of every ocean and inhabit every depth zone from the intertidal seashore down to …
Echinoderm | Definition, Characteristics, Species, & Facts
WEBAug 6, 2024 · Echinoderm, any of a variety of invertebrate marine animals belonging to the phylum Echinodermata, characterized by a hard, spiny covering or skin. Living species include sea lilies, sea urchins, sea cucumbers, starfishes, basket stars, and sea daisies. Learn more about echinoderms.
Introduction to the Echinoidea - University of California Museum …
WEBThe Echinoidea. Introduction to the Echinoidea. Left: A long-spined sea urchins on a coral reef at Contadora Island, off the Pacific Coast of Panama. Center: Unidentified sand dollar skeleton with spines removed. Right: Living heart urchin, Brissus laticarinatus, from the eastern coast of Thailand. Echinoids are one of the more diverse and ...
Echinoderms - Smithsonian Ocean
WEBThere are about 7,000 species of living echinoderms and each of them falls into one of five categories. Though most people distinguish between sea urchins and sand dollars, the two are actually members of the same class, Echinoidea. Here, we distinguish them separately. Sea Stars (Asteroidea)
The Echinoid Directory - Natural History Museum
WEBThey belong to the Echinoidea, one of the five classes of the phylum Echinodermata, the others being holothurians, crinoids, starfish and brittlestars. Like all echinoderms, echinoids have a skeleton composed of calcitic plates embedded in their skin (their skeleton is internal, like ours).
sea urchins - Encyclopedia of Life
WEBEchinoidea (Sea Urchins) is a class of echinoderms. There are 3412 species of Sea Urchins, in 728 genera and 139 families. This class has been around since the middle ordovician epoch. Dead Sea Urchins form shallow marine sediment s. They are omnivores.