Animal mesoderm forms by enterocoelic pouching, through invagination of the endoderm. The main deuterostome phyla are the Echinodermata and the Chordata. Echinoderms are exclusively marine and include starfish, sea urchins, and sea cucumbers. The chordates are dominated by the vertebrates (animals with backbones), which consist of fishes, amphibians, reptiles, birds, and mammals. The deuterostomes also include the Hemichordata (acorn worms). The Ecdysozoa are protostomes, named after their shared trait of ecdysis, growth by moulting. They include the largest animal phylum, the Arthropoda, which contains insects, spiders, crabs, and their kin. All of these have a body divided into repeating segments, typically
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