Endoskeleton three phyla and one subclass of animals, endoskeletons of various complexity are found: Chordata, Echinodermata, Porifera, and Coleoidea. An endoskeleton may function purely for support (as in the case of sponges), but often serves as an attachment site for muscle and a mechanism for transmitting muscular forces. A true endoskeleton is derived from mesodermal tissue. Such a skeleton is present in echinoderms and chordates. The poriferan 'skeleton' consists of microscopic calcareous or siliceous spicules or a spongin network. The Coleoidae do not have a true endoskeleton in the evolutionary sense; there, a mollusk exoskeleton evolved into several sorts of internal
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