The largest carnivorous dinosaur ever recorded is the Spinosaurus, which measured 50 feet in length and weighed 7 ½ tons. However, recent examinations of skull fragments suggest that the Spinosaurus measured 17 m (56 ft) long and weighed 7-9 tonnes (15,400 - 19,800 lb), making it possibly the largest ever land-based predator ever known. The Spinosaurus roamed present-day Sahara, 100 million years ago during the Cretaceous period and fossil evidence suggests its main diet consisted of fish, as opposed to other dinosaurs. Other large carnivorous dinosaurs include Carcharodontosaurus saharicus, which grew to be about 39–44 feet long and weighed about 6.5 – 8 tonnes (7.2-8.8 tons) , and Tyrannosaurus Rex, which is among the largest theropods. However, the exact size of these dinosaurs is difficult to determine due to incomplete fossils.