Rare behind-the-scenes tours of 18 million specimens

The Academy of Natural Sciences' visitors may associate the nation's oldest natural history museum merely with dioramas and dinosaurs, but behind the scenes world-renowned scientists conduct groundbreaking research and the academy is in possession of an enviable collection of some 18 million specimens representing all manner of animal, vegetable and mineral.

The Academy is celebrating its bicentennial this year. For what's believed to be the first time in 200 years, curators will bring the public into the labyrinthine museum's normally off-limits nooks and crannies for daily tours. These pictures were taken on March 23, 2012.

In Photo:

In this picture, Doug Wechsler, director of the Visual Resources for Ornithology, shows a pheasant in the collection at the Academy of Natural Sciences, Philadelphia.

Source: AP