Starfish first appeared in the fossil record in the Cambrian. The first known asterozoans were the Somasteroidea, which exhibit characteristics of both groups. Starfish are infrequently found as fossils, possibly because their hard skeletal components separate as the animal decays. Despite this, there are a few places where accumulations of complete skeletal structures occur, fossilized in place in Lagerstätten — so-called "starfish beds". By the late Paleozoic, the crinoids and blastoids were the predominant echinoderms, and some limestones from this period are made almost entirely from fragments from these groups. In the two major extinction events that occurred during the late
Echinoderma rounded cells, and a brownish cap and stipe, with brown scales. The name comes from the Greek "echinos" (ἐχῖνος) meaning a hedgehog or sea-urchin and "derma" (δέρμα) meaning skin, referring to the spiny cap surface. The noun "derma" is neuter and therefore if the species name is an adjective, it needs to take the neuter ending (example: "Echinoderma asperum"). Echinoderma Echinoderma is a genus of fungi in the family Agaricaceae. Its members were for a long time considered to belong to genus "Lepiota" and the group was then circumscribed by French mycologist Marcel Bon in 1981 as a subgenus of