The remains of a partially mummified possum carcass after being removed from the wall lining of a building being demolished. As Temperance Brennan would have commented - "The drying out processes that took place after death have created tension in the platysma extensor causing the marsupial's jaw to open in a long frozen screech". - End Quote There were half a dozen similar carcasses and several live ones which ran off blinking into the daylight. (Possums are nocturnal). The image uploaded has been heavily posterized however as it was almost unrecognisable as a thumbnail I have used a colored thumbnail.