Allosaurus is a genus of large theropod dinosaur in the family Allosauridae. There are three known species: the type species is Allosaurus fragilis, and it is accompanied by the similar Allosaurus jimmadseni (distinguished based on the shape of its skull) and the European species Allosaurus europaeus. These dinosaurs lived during the late Jurassic period, with fossil remains dated between 155 and 145 million years old. Its remains are found in western North America and Europe.
