Tyrannosaurus rex and Theropod dinosaur

Tyrannosaurus rex 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.

Theropod dinosaur and Tyrannosaurus rex are semantically related. In some cases you can use "Theropod dinosaur" instead a noun phrase "Tyrannosaurus rex".

Theropod dinosaur noun - Any of numerous carnivorous dinosaurs of the Triassic to Cretaceous with short forelimbs that walked or ran on strong hind legs.

Tyrannosaurus rex and theropod dinosaur are semantically related. Sometimes you can replace phrase "Tyrannosaurus rex" with "Theropod dinosaur", this phrases are similar.