interdigital webbing
... that possible traces of interdigital webbing have been preserved in fossils of pakicetids, the ancestors of whales?
... that possible traces of <b id="mwAUk"><a href="./Interdigital_webbing" id="mwAUo" rel="mw:WikiLink" title="Interdigital webbing">interdigital webbing</a></b> have been preserved in fossils of <a class="mw-redirect" href="./Pakicetid" id="mwAUs" rel="mw:WikiLink" title="Pakicetid">pakicetids</a>, the ancestors of <a href="./Cetacea" id="mwAUw" rel="mw:WikiLink" title="Cetacea">whales</a>?