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
Chloroflexi (phylum) Class Thermomicrobia Class Chloroflexia The name ""Chloroflexi"" is a Neolatin nominative case masculine plural of "Chloroflexus", which the name of the first genus described. The noun is a combination of the Greek adjective "chloros, -a, on (χλωρός, -ά, -όν)" meaning "greenish-yellow" and the Latin masculine passive perfect participle "flexus" (of "flecto") meaning "bent" to mean "a green bending". It should be therefore noted that the etymology is not due to chlorine, an element (dephlogisticated muriatic acid air) which was confirmed as such in 1810 by Sir Humphry Davy and named after its pale green colour. Another phylum with the same