by William T. Kratz

 historical research of the whale  fossil records  related species geographic distribution  whale evolution video

 In 1693 John Ray classified whales as mammals  In 1859 Charles Darwin believes that whales have similarities to the black bear  In 1883 William Flower suggested whales evolved from ungulates  Philip D. Gingerich Ph.D. researched whale fossils in Pakistan and Egypt from1970s through 1990s  Hans Thewissen led the team that reconstructed the skeleton of the first land mammal ancestor of the whale

 Indohyus  Pakicetus  Ambulocetus natans  Rodhocetus  Basilosaurus  Dorudon

 Indohyus literally means India’s Pig  Fossil founded by Indian geologist Ranga Rao  Skeleton assembled by Hans Thewissen  Fossil dates back 60 mya  Even toed ungulate  Size of a modern house cat  Chemical tests on teeth and bone analysis revealed that Indohyus spent much of its time wadding in water as a hippo would  Bone structure around the ear revealed unique similarities to that of the modern whale

 First Archaeocete  Evolved 52 mya  Founded by Philip Gingerich in 1983 in Pakistan  Pakicetus was about the size of a wolf  Primarily was a land mammal but spent much time in the water.  Had sharp teeth of a carnivore  Like Indohyus, had similar bone structure around ear to that of modern whales

 Ambulocetus “walking whale” was found in 1992 by Thewissen  Fossil dates back 49 mya  3 meters in length, hind legs were well adapted for swimming  Skeleton suggests that it hunted like a crocodilian  Ambulocetus had no external ear, probably kept head close to ground to detect vibrations of land prey  Anatomy of spinal column-swam with tail going up and down  Had an adaptation in the nose that enabled it to swallow underwater, and its periotic bones had a structure like those of whales, enabling it to hear well underwater

 mya in Pakistan by Stromer 1908  Lumbar vertebrae-neural spines higher, more developed tail for swimming  Sacral vertebrae not fused- more flexibility, body developed for swimming  Femur was a third shorter than that of the Ambulocetus’  Skull elongated  Ears pushed further back  Smaller eyes  First ancestor to be more water orientated that land

 Basilosaurus “regal lizard”  First skeletal parts found in Louisiana and Alabama in the 1830’s  Fossil dates back mya  Could grow up to 20 meters  First ancestor that was all aquatic  Complete set of hind limb bones and a pelvis, but very small  Formation of blow hole-single large nostril to the top of the head  First to have tail fluke- due to structure of vertebral proportions

 Dorudon was founded by Gingerich in 1994  Fossil dates back mya  Found in North America, India, and Pakistan  Originally thought to be an intermediate Basilosarus, ranging from 4-5 meters  Carnivorous, feeding on small fish and mollusks  Looked very similar to modern whales, but lacked the melon organ  Also a completely water orientated mammal.

 Distribution of Basilosaurus and Dorudon widely spread vs. Ambulocetus and Rodhocetus restricted to one area in India, Pakistan region

 YlY&feature=related YlY&feature=related  WHALE EVOLUTION ANIMATION WHALE EVOLUTION ANIMATION