[Campbell Biology P.780] Which of the following features of Tiktaalik represents a significa... | Practice Question

Which of the following features of Tiktaalik represents a significant evolutionary step towards tetrapods, differentiating it from earlier fish?

  • A: Presence of gills and scales
  • B: Having a full set of ribs and a neck
  • C: Being entirely aquatic throughout its life
  • D: Having pectoral fins instead of limbs

Explanation

The text explicitly states that 'unlike a fish, Tiktaalik had a full set of ribs that would have helped it breathe air and support its body. Also unlike a fish, Tiktaalik had a neck, allowing it to move its head about.' These features are key adaptations seen in tetrapods.