Assertion: sand dollar | /r/Synonym | endoskeleton
Facets:
Source sentences:
text: The test of the sand dollar is its endoskeleton—it is called an endoskeleton because it lies underneath the sand dollar's spines and skin, and it is made of fused calcareous plates.
text: The test of the sand dollar is its endoskeleton-it is called an endoskeleton because it lies underneath the sand dollar's spines and skin, and it is made of fused calcareous plates.