Saurophaganax maximus

The "Reptile Eating Master" was an enormous allosaurid, possibly the largest ever found.  It lived during the late Jurassic period in the western United states. This theropod was probably 11-13 meters in length and somewhere around 4-7 metric tons in weight.  Saurophaganax was likely the only Morrison theropod large enough to tackle the immense diplodocids in its environment.