inarticulates

Updated: May 5, 2025

Both of these genera have lived on during the millions of years of geological time since their introduction, handing down from generation to generation with hardly any change to their descendants now living off our shores the characters impressed upon them at the beginning. In the Cambrian the inarticulates predominate, though the articulates grow common toward the end of the period.

William Harmon Norton - The Elements of Geology