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
Subgroups of Amish affiliation as "a cluster of two or more districts with at least twenty years of shared history". They continue: "affiliated congregations share similar Ordnungs, which specify distinctive lifestyles and visible symbols that set them apart from other affiliations". When referring to affiliations Amish themselves speak of "our people" ("unser Leit") and "our way" to do things. By 2012 there were more than 40 affiliations, with smaller subgroups within some affiliations counted, there were more than 65. In addition to that, there were more than 130 fairly independent congregations. The majority of affiliations reflects mainly the different local "Ordnungen" (Orders) in