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
Branching order of bacterial phyla (Woese, 1987) was not based on molecular phylogeny. Eukaryotes are a mosaic of different lineages: Consequently, in Woese (1987) the group is referred to as urkaryote. The clade composed of Archaea and the nuclear genome of eukaryotes is called Neomura by T. Cavalier-Smith Branching order of bacterial phyla (Woese, 1987) There are several models of the Branching order of bacterial phyla, one of these was proposed in 1987 paper by Carl Woese. The branching order proposed by Carl Woese was based on molecular phylogeny, which was considered revolutionary as all preceding models were based on discussions of morphology. ("v." Monera). Several models