So is the "Marsupial Lion" really extinct?
The enormous number of reasonably reliable witness over more than a century really cannot be dismissed.
So, what if the Marsupial Lion (that had a number of different members in its family - the Thylacoleonidae) has a surviving nocturnal descendant?
Supposedly these animals have been extinct since the megafauna that they preyed on became extinct. If we believe the current bumff that was brought about by climate change or maybe their environment being changed by the use of burning by pre-aboriginals in the last thirty thousand or so years. Disputed aboriginal rock paintings in the Kimberley "may" show a marsupial lion rather than the easier explanation that it is a mainland Thylacine (recognisable as a Tasmanian Tiger) that is also reasonably reliably believed to be extinct in Tasmania now.
That might explain this animals presence rather than ideas that they are escaped panthers or puma, descendants of chinese cats brought in the goldrush, cats reverting to their pre-domestic ancestry or American military mascots left behind.
Bob