Assertion: living echinoderm | /r/HasAspect | internal skeleton
Facets:
Source sentences:
text: Although all living echinoderms have a pentamerous (five-part) radial symmetry, an internal skeleton, and a water-vascular system derived from the coelom (central cavity), their general appearance ranges from that of the stemmed, flowerlike sea lilies, to the wormlike, burrowing sea cucumbers, to the heavily armoured intertidal starfish or sea urchin.