Suggestions as to how it arose include animals getting stuck in a bog, to becoming trapped in deep mud, to falling victim to drought-induced mortality around a waterhole, to getting trapped in a spring-fed pond or seep. Regardless of the cause, the great quantity of well-preserved "Allosaurus" remains means the animal is one of the best-known theropods. Individuals of almost all ages and sizes are found, from less than 1 meter (3.3 ft) to 12 meters (39 ft) long.