Oryzomys nelsoni
... that the extinct Mexican rice rat Oryzomys nelsoni has only been collected once?
... that the extinct Mexican <a href="./Oryzomyini" id="mwCEE" rel="mw:WikiLink" title="Oryzomyini">rice rat</a> <i id="mwCEI"><b id="mwCEM"><a href="./Oryzomys_nelsoni" id="mwCEQ" rel="mw:WikiLink" title="Oryzomys nelsoni">Oryzomys nelsoni</a></b></i> has only been collected once?