Endoskeleton
From Free net encyclopedia
Image:Swordfish skeleton.jpg An endoskeleton is an internal support structure of an animal. Three phyla of animals possess endoskeletons of various complexity: Chordata, Echinodermata, and Porifera. the endoskeleton allows the body to move and gives the body structure and shape. 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.
