history of plesiosaur research
... that multiple Leptocleidus skeletons have been found preserved as gemstone quality opal over the course of the history of plesiosaur research?
... that multiple <i id="mwBS4"><a href="./Leptocleidus" id="mwBS8" rel="mw:WikiLink" title="Leptocleidus">Leptocleidus</a></i> skeletons have been found preserved as <a href="./Gemstone" id="mwBTA" rel="mw:WikiLink" title="Gemstone">gemstone</a> quality <a href="./Opal" id="mwBTE" rel="mw:WikiLink" title="Opal">opal</a> over the course of the <b id="mwBTI"><a href="./Timeline_of_plesiosaur_research" id="mwBTM" rel="mw:WikiLink" title="Timeline of plesiosaur research">history of plesiosaur research</a></b>?