MINNEAPOLIS — Workers renovating the old Dayton’s department store in downtown Minneapolis have discovered a mystery: the mummified remains of a monkey.

Crews found the carcass last week in an air duct on the seventh floor of the century-old building.

Cailin Rogers is a spokeswoman for the Dayton’s Project, an office, retail and restaurant complex going into the building. She says developers don’t know where the monkey came from or how it ended up in the air duct.

A historic site called Old Minneapolis posted a photo of the monkey on its Facebook page and solicited answers.

Alan Freed is one of the site’s co-administrators. He says one likely answer came from someone who posted on the page saying a longtime Dayton’s employee told him a monkey escaped from an eighth-floor pet store into the air conditioning ductwork in the 1960s.