The 48-million-year-old skeleton of Indohyus spent much of its life in water and is a close relative of whales. The cell phone is for size comparison.
Credit: NEOUCOM

Finding the Four-Footed Ancestors of Whales
News story originally written on December 20, 2007

Scientists have known for a long time that whales, the largest marine mammals, have distant relatives that lived on land millions of years ago. A team of scientists has been searching for fossils to better understand how whales evolved. In the past 15 years, they have found fossils that show how, over millions of years, these mammals evolved from small four-footed land animals to extra large marine animals.

Now the team of scientists has discovered the closest known fossil relative of whales that lived on land. This extinct species lived approximately 48 million years ago. The team studied hundreds of fossil bones and they found that the skulls and ears of the fossils are similar to whales living today.

It may have lived on land, but there is fossil evidence that the whales’ four-footed ancestor spent much of its time in the water. A fox-sized mammal that looked something like a tiny deer, its bones are similar to the bones of animals that wade slowly in shallow water, such as the hippopotamus today. And its teeth are similar to aquatic animals.

Last modified December 20, 2007 by Lisa Gardiner.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

What Is a Fossil?

Fossils are evidence of what life was like long ago. The oldest fossils are over three billion years old and the youngest fossils are about 10,000 years old. Scientists that study fossils know that creatures...more

Triggers of Volcanic Eruptions in Oregon's Mount Hood Investigated

Scientists have learned that Mount Hood, Oregon's tallest mountain, has erupted in the past due to the mixing of two different types of magma. Adam Kent, a geologist at Oregon State University, says this...more

Oldest Earth Mantle Reservoir Discovered

The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core. The mantle is made up of many different reservoirs that have different chemical compositions. Scientists...more

It’s Not Your Fault – A Typical Fault, Geologically Speaking, That Is

Some faults look strong and like they wouldn’t cause an earthquake. But it turns out that they can slip and slide like weak faults causing earthquakes. Scientists have been looking at one of these faults...more

Lower Solar Activity Linked to Changes in Sun's Conveyor Belt

The sun goes through cycles that last approximately 11 years. These solar cycle include phases with more magnetic activity, sunspots, and solar flares. They also include phases with less activity. The...more

Growth Spurt in Tree Rings Prompts Questions About Climate Change

Studying tree rings doesn't only tell us the age of that tree. Tree rings also show what climate was like while the tree was alive. This means that tree rings can tell us about climates of the past. Two...more

Did Life First Develop in a Mica Sandwich at the Bottom of a Primordial Sea?

Earth's first life form may have developed between the layers of a chunk of mica sitting like a multilayered sandwich in primordial waters, according to a new hypothesis. The mica hypothesis, which was...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA