J. G. M. "Hans" Thewissen is Ingalls-Brown Endowed Professor in the Department of Anatomy and Neurobiology at Northeast Ohio Medical University. His main research interest is the study of whales, particularly their adaptations to life in water and their origin as land mammals. He discovered in 1994 the skeleton of the first-known whale that could walk on land (Ambulocetus), and he has led more than ten field expeditions each to Pakistan and India, collecting fossil whales. He is coeditor of Encyclopedia of Marine Mammals (2002), Emergence of Whales (1998), and Sensory Evolution on the Threshold (UC Press, 2008).

1. A Wasted Dig
Fossils and War
A Whale Ear

2. Fish, Mammal, or Dinosaur?
The King Lizard of Cape Cod
Basilosaurid Whales*
Basilosaurids and Evolution

3. A Whale with Legs
The Black and White Hills
A Walking Whale

4. Learning to Swim
Meeting the Killer Whale
From Dog-Paddle to Torpedo
Ambulocetid Whales*
Ambulocetus and Evolution

5. When the Mountains Grew
The High Himalayas
Kidnapping in the Hills
Indian Whales

6. Passage to India
Stranded in Delhi
Whales in the Desert
A 150-Pound Skull

7. A Trip to the Beach
The Outer Banks
A Fossilized Coast

8. The Otter Whale
The Whale with No Hands
Remingtonocetid Whales*
Building a Beast out of Bones

9. The Ocean Is a Desert
Forensic Paleontology
Drinking and Peeing
Fossilized Drinking Behavior
Walking with Ambulocetus

10. The Skeleton Puzzle
If Looks Could Kill
How Many Bones Make a Skeleton?
Finding Whales' Sisters

11. The River Whales
Hearing in Whales
Pakicetid Whales*
September 11, 2001

12. Whales Conquer the World
A Molecular SINE
The Black Whale
Protocetid Whales*
Protocetids and History

13. From Embryos to Evolution
A Dolphin with Legs 
The Marine Park at Taiji 
Shedding Limbs 
Whaling in Taiji
 
14. Before Whales 
The Widow's Fossils 
The Ancestors of Whales 
Indohyus* 
A Trust for Fossils 

15. The Way Forward 
The Big Question 
Tooth Development 
Baleen as Teeth 

Notes 
Index 
*These six headings summarize the biology of the six fossil groups that form the transition between whales and their terrestrial ancestors. Their relationships to each other and to the living families of cetaceans (whales, dolphins, and porpoises) are given in figure 66.

Hans Thewissen, a leading researcher in the field of whale paleontology and anatomy, gives a sweeping first-person account of the discoveries that brought to light the early fossil record of whales. As evidenced in the record, whales evolved from herbivorous forest-dwelling ancestors that resembled tiny deer to carnivorous monsters stalking lakes and rivers and to serpentlike denizens of the coast.

Thewissen reports on his discoveries in the wilds of India and Pakistan, weaving a narrative that reveals the day-to-day adventures of fossil collection, enriching it with local flavors from South Asian culture and society. The reader senses the excitement of the digs as well as the rigors faced by scientific researchers, for whom each new insight gives rise to even more questions, and for whom at times the logistics of just staying alive may trump all science.

In his search for an understanding of how modern whales live their lives, Thewissen also journeys to Japan and Alaska to study whales and wild dolphins. He finds answers to his questions about fossils by studying the anatomy of otters and porpoises and examining whale embryos under the microscope. In the book's final chapter, Thewissen argues for approaching whale evolution with the most powerful tools we have and for combining all the fields of science in pursuit of knowledge.