A Jaw-Breaking Existence : Science: A study of La Brea fossils shows that mealtimes were tough in prehistoric Los Angeles. Saber-toothed cats and other predators often broke their teeth scrambling for food.

Despite the rich abundance of animal life in California 30,000 years ago, a predator’s life on Wilshire Boulevard apparently was no picnic.

Pickings were so lean in prehistoric Los Angeles that the lions, saber-toothed cats and dire wolves who formed the local lunch rush in the eons before fast-food fajitas and buffalo wings literally broke their teeth in the fierce scramble for the catch of the day, a new study by two UCLA researchers shows.

By examining the fossil fangs in hundreds of ancient skulls from the La Brea Tar Pits, the paleontologists determined that the gnarling of bones and gnashing of saber-teeth was so frenetic that fractured dentures were three times more common than among modern predators, researchers Blaire Van Valkenburgh and Fritz Hertel found.

The research, published today in the journal Science, adds new detail to the picture of life in North America at a time when mastodons and giant running bears held sway along the avenues where today ragtops and pickups prowl.

“We know how the modern animals live and hunt, and we can infer any similarities from the fossils. It lends some insight into the interactions between the predator and prey,” said Hertel, a doctoral student at the UCLA Department of Biology.

“The animals at La Brea were probably feeding to a larger extent on bone, utilizing the carcasses more efficiently, which would suggest that competition would be more intense back then,” he said. “Instead of chomping on it and cruising off, the animals were probably guarding their kills more carefully, eating more, perchance they may lose it to something else.”

That is what the researchers deduced from something so simple, and revealing, as the worn stumps of broken teeth.

In all, the researchers examined more than 4,900 ancient teeth in collections at the George C. Page Museum and the Los Angeles County Museum, from the jaws of American lions, saber-toothed cats, coyotes and dire wolves trapped in the tar pits between 10,000 and 36,000 years ago.

They compared those fossil remnants of carnivorous smiles to teeth from modern leopards, jaguars, bone-cracking hyenas and cheetahs.

They found the proportion of teeth broken during the lives of the extinct predators ranged from 5% to 17%, compared to no more than 3% among modern meat-eaters.

Of all the extinct predators, the saber-toothed tiger, with its distinctive dagger-like fangs, would be expected to be most at-risk. The fossils showed that the animal was twice as likely as a modern lion to have fractured teeth.

Despite their prominence, however, the large fangs were no more likely to break than any other tooth in their mouths, suggesting that the large cats may have killed their prey differently than do modern big cats. The researchers speculate that the cats may have lessened the risk to their fangs by using their massive forelimbs to hold down their prey before ripping at it with killing bites.

Although modern coyotes differ little in most respects from their ancestors who stumbled ino the tar pits, their teeth are less likely to be fractured, leading the researchers to suggest that a change in eating habits might be responsible.

To ensure that the ancient dental problems were not simply a local problem, the researchers also examined the remains of dire wolves exhumed from a cave in Mexico and a tar seep in Peru. “We looked at dire wolf in those deposits and found they had significantly higher breakage. That suggests very strongly that it was not a local phenomena,” Hertel said.