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
Korarchaeota Korarchaeota In taxonomy, the Korarchaeota are a phylum of the Archaea. The name is derived from the Greek noun koros or kore, meaning "young man" or "young woman," and the Greek adjective archaios which means "ancient." They are also known as Xenarchaeota. Korarchaeota is regarded as a phylum, which itself is part of the archaeal TACK superphylum which encompasses Thaumarchaeota, Aigarchaeota, Crenarchaeota and Korarchaeota. Analysis of their 16S rRNA gene sequences suggests that they are a deeply branching lineage that does not belong to the main archaeal groups, Crenarchaeota and Euryarchaeota. Analysis of the genome of one korarchaeote that was