Bite of Ancient Saber-toothed Marsupial was Weaker than a Housecat, but it Killed with Precision

An ancient saber-fanged marsupial known as Thylacosmilus, one of the super predators of its time during the Miocene era, could not rely on its massive teeth alone to make a kill - its jaws lacked the power to deliver a bite stronger than a house cat, according to the latest research on the creature.

Thylacosmilus had two dagger-like teeth rooted so far into its head that they encroached upon its brain chamber, yet the creature lacked the muscular jaw strength to wield the fangs as flesh-ripping weapons, the latest research reports, suggesting the creature instead used the power of its forearms to wrestle prey to the ground and then, like a vampire, inserted its fangs into the windpipe or arteries of its victim to complete the kill in a precise piercing move.

"Frankly, the jaw muscles of Thylacosmilus were embarrassing. With its jaws wide open this 80-100 kg 'super-predator' had a bite less powerful than a domestic cat," said Stephen Wroe, a paleontologist and the leader of the Thylacosmilus research team at the University of South Whales.

To reach his conclusion, Wroe and his colleagues constructed three-dimensional computer models of the Thylacosmilus, the true saber-toothed cat Smilodon fatalis and the leopard, which has conical front teeth like Smilodon, albeit much smaller. The models were compared and contrasted in a "digital crash test" of simulated biting and killing behavior.

"We found that both saber-tooth species were similar in possessing weak jaw-muscle-driven bites compared to the leopard, but the mechanical performance of the saber-tooths skulls showed that they were both well-adapted to resist forces generated by very powerful neck muscles," Wroe said in a statement.

"Bottom line is that the huge sabers of Thylacosmilus were driven home by the neck muscles alone and - because the sabre-teeth were actually quite fragile - this must have been achieved with surprising precision," Wroe said.

"For Thylacosmilus - and other saber-tooths - it was all about a quick kill."

Wroe said the bizarre, pouched creature, with its enormous fangs and no jaw power to wield them, "looked and behaved like nothing alive today."

Wroe and his colleagues' research is published in the journal PLoS ONE.