Bones from an owl pellet (sighting 4566395; 13/4/24). I'm assuming this was a possum/glider? Hoping the jaw and teeth are enough to ID? Have other teeth and bones as well, but not many.
Retained sectorial premolar, and size, support your ID as possum or glider. A small potoroid is another possibility (eg LN Potoroo). Owls and diurnal raptors often find animals we are not aware of in an area. Need comparison to reference material to go further.