Tyrannosaurus and Tyrannosaur

Tyrannosaurus noun - Large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America.

Tyrannosaur is a synonym for tyrannosaurus. In some cases you can use "Tyrannosaur" instead a noun "Tyrannosaurus".

Tyrannosaur noun - Large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America.

Tyrannosaurus is a synonym for tyrannosaur. You can use "Tyrannosaurus" instead a noun "Tyrannosaur".