Source : Webster's Revised Unabridged Dictionary (1913)

Potoroo \Po`to*roo"\, n. (Zo["o]l.)
   Any small kangaroo belonging to {Hypsiprymnus}, {Bettongia},
   and allied genera, native of Australia and Tasmania. Called
   also {kangaroo rat}.

Source : WordNet®

potoroo
     n : Australian rat kangaroos