Unlike other sea turtles, green turtles only have one pair of prefrontal scales.
Green turtles have only one pair of prefrontal scales, although other species of sea turtles have multiple pairs. Hawksbill turtles, for example, have two pairs of prefrontal scales.
Sources: (Hersh, 2016; Witzel, 1982)
Image: Kris-Mikael Krister