Chapter 19, Problem 4TYK

Why were the Tiktaalik fossils an exciting discovery for scientists studying tetrapod evolution?

a. They are the earliest frog-like animal discovered to date.

b. They show that tetrapods successfully colonized land much earlier than previously thought.

c. They have a roughly equal combination of fishlike and tetrapod-like characteristics.

d. They demonstrate conclusively that limbs evolved as lobe-fins dragged themselves from pond to pond during droughts.