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
Bacterial phyla and NCBI lists 120 phyla, including 90 candidate phyla (AC1, Acetothermia, Aerophobetes, Aminicenantes, Atribacteria, Berkelbacteria, BRC1, CAB-I, Calescamantes, CPR1, CPR2, CPR3, EM 3, Fervidibacteria, GAL15, GN01, GN03, GN04, GN05, GN06, GN07, GN08, GN09, GN10, GN11, GN12, GN13, GN14, GN15, Gracilibacteria, Fermentibacteria (Hyd24-12), Hydrogenedentes, JL-ETNP-Z39, KD3-62, kpj58rc, KSA1, KSA2, KSB1, KSB2, KSB3, KSB4, Latescibacteria, marine group A, Marinimicrobia, Microgenomates, MSBL2, MSBL3, MSBL4, MSBL5, MSBL6, NC10, Nitrospinae, NPL-UPA2, NT-B4, Omnitrophica, OP2, OP4, OP6, OP7, OS-K, Parcubacteria, Peregrinibacteria, Poribacteria, RF3, Saccharibacteria, SAM, SBR1093, Sediment-1, Sediment-2, Sediment-3, Sediment-4, SPAM, SR1, TA06, TG2, TM6, VC2, WOR-1, WOR-3, WPS-1, WPS-2, WS1, WS2, WS4, WS5, WS6, WWE3,