Evolution of the Whale
by Emily Chan
Pakicetus
48 million years ago – foraged in streams, 1.75 meters long, nostrils for forward, forelimbs for walking, hind limbs function for walking, no tail flukes
Ambulocetus
47 million years ago - alligator like, fed in the water, 4.15 meters long, forelimbs for walking, hind limbs function for walking, no tail flukes
Maiacetus
46 million years ago - sea lion like, spent some time in land, 3 meter long, forelimbs function for swimming and walking, large hind limbs, no tail flukes
Dorudon
37 million years ago, completely aquatic, 4.5 meters long, nostrils further back on skull, forelimbs become flippers, elongation of the trunk, reduced hind limbs, evolution of tail fluke
Llanocetus
34 million years ago, 9-10 meters long, teeth reduced, first evidence of baleen for filter feeding, nostril far back on skulls, elbow immobile
Modern Whale
Many species including humpback, blue whale, killer and sperm. Mass, length, gestation and lifespan depend on whale species.