Mesotherium
... that Mesotherium ("middle beast") was so named because its discoverer believed it was an intermediate between rodents and pachyderms?
... that <b id="mwDLI"><a href="./Mesotherium" id="mwDLM" rel="mw:WikiLink" title="Mesotherium">Mesotherium</a></b> ("middle beast") <i id="mwDLQ">(skull pictured)</i> was so named because its discoverer believed it was an intermediate between <a href="./Rodent" id="mwDLU" rel="mw:WikiLink" title="Rodent">rodents</a> and <a class="mw-disambig" href="./Pachyderm" id="mwDLY" rel="mw:WikiLink" title="Pachyderm">pachyderms</a>?