Mummified Squirrel?

Okay - I now know that after I post these pictures people will think I'm a collector of dead animal photos...well...I am. I found this mummified squirrel right outside of Ole' Mexican Grill in Arlington, MA. Nature does a great job of preserving things. I can only imagine his demise - perhaps a slippery mid-winter branch...a fall to his death? Or was this a fatality of a secret squirrel war?