Assertion: coral's form | /r/HasProperty | solitary
Facets:
Source sentences:
text: Appearing as solitary forms in the fossil record more than 400 million years ago, corals are extremely ancient animals that evolved into modern reef-building forms over the last 25 million years.
text: Horn corals, which are named for the hornlike shape of the individual structures built by the coral animal, were either solitary or colonial forms.
text: The rugose corals existed in solitary and colonial forms, and were also composed of calcite.