According to Pemberton, the possible ancestors of the devil may have needed to climb trees to acquire food, leading to a growth in size and the hopping gait of many marsupials.He speculated that these adaptations may have caused the contemporary devil's peculiar gait.The size of a small dog, the Tasmanian devil became the largest carnivorous marsupial in the world following the extinction of the thylacine in 1936.
In 1941, the devils, which were originally seen as implacably vicious, became officially protected.
As most of their prey died of the cold, only a few carnivores survived, including the ancestors of the quoll and thylacine.
It is speculated that the devil lineage may have arisen at this time to fill a niche in the ecosystem, as a scavenger that disposed of carrion left behind by the selective-eating thylacine.
Females average four breeding seasons in their life and give birth to 20–30 live young after three weeks' gestation.
The newborn are pink, lack fur, have indistinct facial features and weigh around 0.20 g (0.0071 oz) at birth.