Order Testudines is represented on Mount Desert Island by 3 species in 3 genera in 2 families:
   Chelydridae (1 species) - Chelydra serpentina (snapping turtle).
   Emydidae (4 species) - Chrysemys picta (painted turtle) and Glyptemys insculpta (wood turtle). Reports of Emys blandingii (Blanding's turtle) and Terrapene carolina (eastern box turtle) by the Acadia National Park e-nature web site are doubtful.

Chelydra serpentina (snapping turtle): This photograph was taken by Don Lenahan on 21 April 2007 in the inlet at the south end of the Tarn (Bar Harbor). Almost exactly one year later, 20 April 2008, Don saw a snapping turtle "swimming at the very south end of The Tarn [in the] early afternoon".