How did Tasmanian tiger protected itself?

Answer 1

Believed to be extinct, the Tasmanian tiger, more properly known as the Thylacine, was unable to protect itself against humans, who literally hunted it to extinction.

However, the thylacine was the largest carnivorous marsupial, and at the top of the food chain. With no natural predators, it did not need protection beyond the strong, powerful jaws it had.