Thylacine Adult
The thylacine had become extremely rare or extinct on the
Australian mainland before European settlement of the continent, but it survived on the island of Tasmania along with several other endemic species, including the Tasmanian devil.
Intensive hunting encouraged by bounties is generally blamed for its extinction, but other contributory factors may have been disease, the introduction of dogs, and human encroachment into its habitat. Despite its official classification as extinct, sightings are still reported, though none proven.
Like the tigers and wolves of the Northern Hemisphere, from which it obtained two of its common names, the thylacine was an apex predator. As a marsupial, it was not closely related to these placental
mammals, but because of convergent evolution it displayed the same general form and adaptations. Its closest living relative is thought to be either the Tasmanian devil or numbat.
The modern thylacine first appeared about 4 million years ago. Species of the Thylacinidae family date back to the beginning of the Miocene; since the early 1990s, at least seven fossil species have been uncovered[by whom?] at Riversleigh, part of Lawn Hill National Park in northwest Queensland. Dickson's thylacine (Nimbacinus dicksoni) is the oldest of the seven discovered fossil species, dating back to 23 million years ago. This thylacinid was much smaller than its more recent relatives. The largest species, the powerful thylacine (Thylacinus potens) which grew to the size of a wolf, was the only species to survive into the late Miocene. In late Pleistocene and early Holocene times, the modern thylacine was widespread (although never numerous) throughout Australia and New Guinea.