The 47-million-year-old fossils, found by University of Michigan paleontology Prof. Philip D. Gingerich, graduate student Iyad Zalmout, and colleagues from the Geological Survey of Pakistan and the University of New Hampshire, also show how early whales swam.
"Whales are warmblooded animals like we are---that has been known for a long time," Gingerich explains. "Yet they're so different from other warmblooded, furry things that it's been a mystery, both how they came to live in the sea and what ancestors they might have come from on land."
Some clues have come from studies using immunological, molecular, and genetic techniques to explore relationships among groups of animals. As long ago as 1950, scientists using immunological methods on material from living animals came to the surprising conclusion that whales are most closely related to artiodactyls, a group of hoofed animals that includes cows, sheep, goats, deer, and hippos. But paleontologists, who piece together evolutionary stories from fossils, found the artiodactyl explanation hard to accept. Based on similarities in teeth, they maintained that whales probably evolved from mesonychid condylarths, meat-eating animals that resembled hyenas with hooves.
Gingerich has been searching since the late 1970s for evidence that would clear up the confusion. Working in Egypt in the early 1990s, he found Basilosaurus, a fossil whale with leg, foot and toe bones. Artiodactyls h
Contact: Nancy Ross-Flanigan
University of Michigan