Assertion: sea urchin | /r/PartOf | the class
Facets:
value: in the echinoderm phylum
type: LOCATION
Source sentences:
text: Sea urchins (Strongylocentrotus purpuratus) are small, spiny animals which make up the class Echinoidea in the Echinoderm phylum.
text: Sea urchins and sand dollars make up the class Echinoidea, and the variety of species in this class is quite impressive.