Ceratosaurus

Ceratosaurus was a fairly large Theropod dinosaur of the Jurassic Period.  The other larger Theropods then living were Allosaurus and Torvosaurus.  Both of these other predators probably out competed Ceratosaurus and drove the species to extinction before the end of the Jurassic Period.

Ceratosaurus by a River

Ceratosaurus had three small horns that most likely were only for display.  That is, for showing off to the females of the species.  The nose horn was probably rather sharp and probably up to 20 cm long ...that would be about 8 inches.  (I should have drawn the nose horn longer... I am used to seeing the base or core on Ceratosaurus skulls, but there probably would have been a much longer keratin sheath.  I might fix this drawing tomorrow.)  The brow horns were kind of stumpy.  Ceratosarus' real weapons were sharp blade-like teeth.  The estimated size is about 17 feet or 5.3 meters long and perhaps up to 1500 lbs or 680 kg.  Notice that the Ceratosaur above had 4 fingers.  One finger was quite small and it's presence indicates a more primitive Theropod because that fourth finger evolved away in later more advanced Theropod dinosaurs of the late Jurassic Period.  Note that Ceratosaurus had a row of small armored plates going down its spine.

Allosaurus by a River

Compared to an Allosaurus with a length of up to 40 feet or about 12.5 meters...and a weight and mass of 8,800 lbs & 3992 kg. 

Torvosaurus and Rhamphorhynchus

Torvosaurus was possibly even larger with a length of possibly 40+ feet and a weight and mass of 9,900+ lbs and 4,4900+ kg.   This would have been even larger than Allosaurus