revolution in burrowing
... that a revolution in burrowing marks the base of the Cambrian period, and is followed by the Cambrian explosion of animal diversity?
... that a <b id="mwFuQ"><a href="./Cambrian_substrate_revolution" id="mwFuU" rel="mw:WikiLink" title="Cambrian substrate revolution">revolution in burrowing</a></b> marks the base of the <a href="./Cambrian" id="mwFuY" rel="mw:WikiLink" title="Cambrian">Cambrian</a> period, and is followed by the <a href="./Cambrian_explosion" id="mwFuc" rel="mw:WikiLink" title="Cambrian explosion">Cambrian explosion</a> of animal diversity?