Perhaps you should try some spelling variations:
"Extant faxon" » "Extant fanon", "Extant taxon", "Extant ftaxon", "Extant faon", "Extant faron"
"Extant ftaxon" » "Extant taxon", "Extant fttaxon", "Extant ftaon", "Extant ftaron"
"Extant axon" » "Extant taxon", "Extant aon", "Extant aron"
"Extant saxon" » "Extant staxon", "Extant saon", "Extant saron", "Extant salon", "Extant saxo"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("Extant faxon") OR ("Extant ftaxon"))) OR ((("Extant axon") OR ("Extant saxon"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"Extant faxon\") OR (\"Extant ftaxon\"))) OR (((\"Extant axon\") OR (\"Extant saxon\"))))".
• Removing quotes may allow a broader search: (((( Extant faxon ) OR ( Extant ftaxon ))) OR ((( Extant axon ) OR ( Extant saxon )))).
• Adding a wildcard symbol may retrieve word variants: (((("Extant faxon") OR ("Extant ftaxon"))) OR ((("Extant axon") OR ("Extant saxon"))))*.