A floorless roller coaster is a roller coaster with trains that ride above the track and allow the passenger's legs to dangle. It is a fairly new concept in roller coaster design brought forth by manufacturers Bolliger & Mabillard. The first ever floorless coaster debuted in 1999 at Six Flags Great Adventure in Jackson, New Jersey, USA. The coaster, Medusa now named Bizarro starting the 2009 season, opened to great reviews and continues to earn its place on the Amusement Today Top 50 Steel Coasters list. Recently, B&M have incorporated floorless trains on their Diving Machine roller coasters, such as Griffon and SheiKra. Though they contain floorless trains, the coasters are still not considered floorless coasters. Maurer Söhne had designed their own version of the floorless coaster, a variant of their X-Car, but currently do not have any installations.