100th anniversary of the discovery
... that this month celebrates the 100th anniversary of the discovery of the main Burgess Shale locality?
... that this month celebrates the <b id="mwC1I"><a href="./History_of_the_Burgess_Shale" id="mwC1M" rel="mw:WikiLink" title="History of the Burgess Shale">100th anniversary of the discovery</a></b> of the main <a href="./Burgess_Shale" id="mwC1Q" rel="mw:WikiLink" title="Burgess Shale">Burgess Shale</a> locality?