Platythelphusa
... that the genus Platythelphusa represents the only evolutionary radiation of crabs to have occurred in a freshwater lake?
... that the genus <i id="mwFBI"><b id="mwFBM"><a href="./Platythelphusa" id="mwFBQ" rel="mw:WikiLink" title="Platythelphusa">Platythelphusa</a></b></i> represents the only <a href="./Evolutionary_radiation" id="mwFBU" rel="mw:WikiLink" title="Evolutionary radiation">evolutionary radiation</a> of <a href="./Crab" id="mwFBY" rel="mw:WikiLink" title="Crab">crabs</a> to have occurred in a freshwater lake?