With its seven-inch canines and 200kg (440lb) of muscle, the sabre-toothed tiger has long been thought of as the most ferocious of the big cats. But new research suggests the extinct predator was much more docile than we thought.
The latest study of the creature's skull has added weight to the suggestion that its jaw was too small to inflict lasting damage on its presumed prey. Writing in the Proceedings of the National Academy of Sciences, scientists claim the sabre-toothed cat had a bite only a third of the strength of a modern-day lion.
Using a computer simulation technique known as Finite Element Analysis (FEA) to compare the skulls of the two species, the scientists concluded that the sabre-toothed cat (Smilodon fatalis) did not have anything like the jaw strength of today's big cats.
"For all its reputation, Smilodon had a wimpy bite", said Steve Wroe of the University of New South Wales in Sydney, one of several Australian scientists who carried out the "reverse engineering" research. "It was a bit like a moggy".
The results gleaned from FEA, more commonly used to measure the structural strength of cars, adds to a growing body of evidence suggesting the sabre-toothed cat was a different kind of predator to what had been imagined.
With its short and bulky limbs, powerful neck, and long claws and teeth, it is likely the cat's killing method relied on ambush more than sprinting. Its legs weren't designed for running fast or far, but for sharp acceleration. Stalking until within striking distance, it would wrestle its victim to the ground and sink dagger-like canines deep into its veins. Many contemporary big cats, such as the lion, will chase prey over longer distances and have to use their jaws to sustain a killer bite for several minutes.
According to Mr Wroe, the modern-day lion is a better "all rounder" as a hunter. "Smilodon was massively over-engineered for taking small prey, but was a ruthlessly efficient hunter of big game", he said.
There were several different species of sabre-toothed cats, the last of which is thought to have died out around 11,000 years ago. They are known to have roamed the open woodland of North and South America, and had been thought to prey on much bigger animals.
"There are still many controversies surrounding Smilodon, even though as extinct animals go we know it reasonably well", said John Hutchinson, of the Royal Veterinary College. "Some theories suggest its jaw was too weak to kill, or its teeth would break if it bit something too hard, or it couldn't open its jaw wide. All of these could rewrite its history, but until we've done more research, the controversy will continue."