Synset

from 544 million to about 230 million years ago
<noun.time>

semantic pointers

instance hypernym

era, geological era

part meronym

Permian, Permian period Carboniferous, Carboniferous period Devonian, Devonian period, Age of Fishes Silurian, Silurian period Ordovician, Ordovician period Cambrian, Cambrian period