Source : Webster's Revised Unabridged Dictionary (1913)

Shovelhead \Shov"el*head`\, n. (Zo["o]l.)
   A shark ({Sphryna tiburio}) allied to the hammerhead, and
   native of the warmer parts of the Atlantic and Pacific
   oceans; -- called also {bonnet shark}.

Source : WordNet®

shovelhead
     n : small harmless hammerhead having a spade-shaped head;
         abundant in bays and estuaries [syn: {bonnethead}, {bonnet
         shark}, {Sphyrna tiburo}]