Concavodonta
... that a fossil of Concavodonta described in 1843 has been lost?
... that a fossil of <i id="mwAZA"><b id="mwAZE"><a href="./Concavodonta" id="mwAZI" rel="mw:WikiLink" title="Concavodonta">Concavodonta</a></b></i> described in 1843 has been lost?