Follow the Fossil: Unearthing Ice Age Mysteries

Two saber-toothed cats eating and standing on top of a zebra lying on the ground

General Info

On display beginning May 26, 2023
Free with Museum Admission
Free for Members

Fossils Tell Stories

If you were standing in the middle of Hancock Park in Los Angeles 40,000 years ago you might witness a family of saber-toothed cats triumphantly sharing a kill. How do we know they fed this way and were not lone hunters? Fossils! Fossil evidence can reveal how ancient animals behaved. Discoveries like this one, however, do not happen overnight. It can take many years and countless professionals to piece the story together.

This particular mystery began in 1914 when excavators at Rancho La Brea (now La Brea Tar Pits) started digging up an astonishing number of Ice Age fossils, from saber-toothed cats and mammoths to birds, snakes, and even ancient tree branches. One set of saber-toothed cat hip fossils—a pelvis and a thigh bone—appeared different from the others they had found. The left side of the hip was rough, jagged, and very strangely shaped.

A sketch of the saber-toothed cat pelvis. A mirror reflects the healthy side of the hip, while the contorted side faces outward.
A sketch of the saber-toothed cat pelvis. A mirror reflects the healthy side of the hip, while the contorted side faces outward.
Illustration by Roy L. Moodie, 1930

In the 1930s, a scientist named Roy Moodie took an interest in the strange fossils, noting that the pelvis was the most strikingly abnormal object in the collection of Rancho La Brea fossils. Based on the evidence available at the time, Dr. Moodie thought the cat might have suffered a hunting injury that became badly infected. He felt this could explain the dramatic shape of the bones and published a paper with his hypothesis.

Ancient Bones Meet Modern Medicine

Scientists decided to take another look at the fossils in 2017. By this time, exciting technology called computed tomography (CT) scanning was a popular way to learn more about a fossil without physically cutting it open. It is the same machine used to look inside human bodies at the doctor’s office. Paleontologist Mairin Balisi thought it might be interesting to CT scan the unusual hip fossils. And it is a good thing she did! Surprisingly, the imaging showed bone spurs caused by the bones repeatedly rubbing together. This happens from chronic disease, not from an injury. Through this new information, we learned that the saber-toothed cat had a lifelong condition called hip dysplasia, a disease commonly seen in modern cats and dogs.

A CT scanning machine taking X-rays of the pelvis fossil from multiple angles
A CT scanning machine taking X-rays of the pelvis fossil from multiple angles. Cedars-Sinai, Los Angeles, CA, 2023.
Courtesy Cedars-Sinai
CT scans are turned into a 3D model that shows the inner parts of the fossil.

The Softer Side of Killer Cats

This saber-toothed cat likely walked with a limp, so hunting large prey to eat would have been difficult. Amazingly, the cat somehow survived to adulthood. Dr. Balisi and her team realized a group of other saber-toothed cats might have helped it find food and protected it from harm. By re-studying these fossils using new technology, we learned that saber-toothed cats were probably social like lions, instead of solitary like tigers.

Dr. Mairin Balisi leaning against collection cabinets and holding a saber-toothed cat skull
Through her fossil research, Paleontologist Dr. Mairin Balisi and her team discovered that saber-toothed cats were likely social animals. Alf Museum of Paleontology, CA, 2022.

Staff members and volunteers really sunk their teeth into their work and made these discoveries possible. From careful digging by excavators to curators identifying fossils, to researchers sharing their observations, all efforts helped piece this prehistoric puzzle together.

Through a single set of hip fossils, the world now knows the story of an extraordinary saber-toothed cat that lived thousands of years ago. What is more, we know the preferred dining style of that cat’s entire species!

You can see these unique fossils on display at the museum at La Brea Tar Pits.

Black and white historical photo of two men in hats excavating fossils from a pit
Staff have skillfully removed fossils from the Tar Pits for over 100 years using many of the same tools and techniques used today. The saber-toothed cat fossils in this story were found in Pit 61 in 1914.
Closeup of hands in blue gloves gluing together a fossil
Storing a fossil indefinitely takes a lot of care. Staff in the Fossil Lab gently glue together fragile or broken fossils. The saber-toothed cat fossils have been kept intact since the early 1900s!
Black and white side-view of a dire wold skeleton
We can learn a lot about ancient animal behavior from studying fossils affected by injury or disease. After noticing most dire wolf injuries were to their head and feet, researchers determined they must have hunted by chasing their prey and biting at their legs. The wolves were likely kicked by prey as they tried to take them down.
An aisle of racks with some trays pulled out to show the fossils stored at La Brea Tar Pits
There are millions of fossils stored at La Brea Tar Pits—think of all the prehistoric secrets yet to be uncovered!

A Discussion with Dr. Klapper and Dr. Balisi