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 Amish". In the following, subgroups of Old Order Amish are listed from conservative to progressive: The Nebraska Amish are perhaps the most conservative group of Old Order Amish. They live mostly in Pennsylvania but they also have one small settlement in Ohio. Around 1880, Bishop Yost H. Yoder led nine families from Juniata County, Pennsylvania, to Gosper County in south-central Nebraska, founding an "Old Order" settlement that would last until 1904. Yoder went back to the Kishacoquillas Valley in Pennsylvania in 1881 to assist a conservative Amish group. Because bishop Yoder was living in Nebraska for some time, and the