Search Result for "silurian period":
Wordnet 3.0

NOUN (1)

1. from 425 million to 405 million years ago; first air-breathing animals;
[syn: Silurian, Silurian period]



WordNet (r) 3.0 (2006):

Silurian period
    n 1: from 425 million to 405 million years ago; first air-
         breathing animals [syn: Silurian, Silurian period]