A newly updated exhibit, "Back to the Sea: The Evolution of Whales," opening April 9, 2011 at the University of Michigan Exhibit Museum of Natural History, presents the story of how whales evolved from typical land-dwelling mammals to creatures that spend their whole lives in the sea.
Photo by Nancy Ross-Flanigan
The exhibit showcases decades of scientific detective work by a team led by U-M paleontologist Philip Gingerich.
Photo by Iyad S. Zalmout
Since the 1980s, Gingerich and colleagues have located and mapped the fossilized remains of more than one thousand whales in an area of the Egyptian desert known as Wadi Al-Hitan (Valley of the Whales), now a UNESCO World Heritage site.
Photo by Philip Gingerich
Wadi Al-Hitan is desert now, but 37 million years ago, the area was under water. Whales, sea cows and other marine life flourished there. It is the remains of these ancient animals that Gingerich and his team excavate and study.
Photo by Philip Gingerich
One early whale that lived 37 million years ago was Dorudon. It swam like a modern whale, using its big, flattened tail and fluke to propel itself through the water. Its large, sharp teeth suggest it was a predator that probably preyed on fish. Dorudon, or a species of early whale much like it, probably was the ancestor of all modern whales.
Illustration by John Klausmeye
A virtually complete skeleton of Dorudon is on display as part of the "Back to the Sea" exhibit.
Photo by Dan Erickson
A long, snake-like whale called Basilosaurus also lived in the Wadi Al-Hitan area 37 million years ago. It probably swam more like an eel than like a modern whale. Like Dorudon, Basilosaurus was a predator. In fact, Basilosaurus may have preyed on Dorudon! The 50-foot-long Basilosaurus skeleton in the "Back to the Sea" exhibit is the latest addition to the Exhibit Museum's Hall of Evolution.
Photo by Dan Erickson
A member of Gingerich's team discovered the fossil in 1987. Eventually the whole skeleton was excavated and shipped to U-M for cleaning and study.
Photo by Alan McWaters
Replicas of the bones were made for the exhibit and for study and exchange with other institutions. Students pitched in to help with the painstaking work of cleaning the bones and molding and casting the replicas. Here, Karie Whitman works on a cast of the skull.
Photo by William Sanders
Gingerich and coworkers also have made significant fossil whale discoveries in Pakistan.
Photo by Iyad S. Zalmout
Pakicetus, discovered by chance in Pakistan in 1977, was a wolf-sized, early whale that lived 47 million years ago. This whale could swim but wasn't well-adapted to water and probably spent some of its time on land. It had ear bones like those of modern whales, but none of the skull modifications that would give it good hearing in water. Gingerich calls it "a very early experiment in whale evolution."
Illustration by John Klausmeyer
Maiacetus also lived around 47 million years ago. An 8.5-foot-long male Maiacetus skeleton is on display in the exhibit, along with a hands-on cast of the skeleton as it was before the bones were freed from the rock in the laboratory.
Illustration by John Klausmeyer
When Gingerich discovered the first Maiacetus fossils in Pakistan in 2000, he was confused by finding small teeth along with ribs that seemed too big to have come from the same animal. Further digging revealed the specimen was a female whale with a fetus -- a very rare find. The name Maiacetus means "mother whale."
Photo by Michigan Productions
The extraordinary fossil, which can be seen in a full-sized photo in the exhibit, shows that the baby whale's head was facing back toward the mother's pelvis, suggesting it was ready to be born head-first, like a land-dwelling mammal. Being able to give birth in water was one of the last adaptations early whales had to make before they became fully aquatic.
Photo by Michigan Productions
