Extinct birds of Mauritius (5)
I believe the answer is:
dodos
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">extinct birds of mauritius</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dodos that I've seen before include "They never got up" , "Extinct flightless birds" , "Extinct birds of Mauritius" , "they're no more" .)