Triceratops is a dinosaur—and a cow is definitely not a dinosaur!

That one was pretty easy, let’s try something harder...

A duck is a dinosaur. That’s because it’s a bird, and birds are living dinosaurs.

Back in the Cretaceous period there were many types of dinosaurs, but they were all wiped out by the asteroid impact about 66 million years ago—all except the avian dinosaurs, that is.

Every bird alive today evolved from avian dinosaurs. Just as humans are mammals, birds are dinosaurs.

The woolly mammoth is an extinct mammal related to today’s elephants—it's definitely not a dinosaur!

A chicken is a type of bird and remember: birds are living dinosaurs.

Pterosaurs are an extinct group of flying reptiles. They are not dinosaurs, although they lived at the same time as dinosaurs. And even though they can fly, they are not related to birds.

A dodo is an extinct bird and birds are living dinosaurs.

The dodo was alive around 400 years ago on the island of Mauritius in the Indian Ocean. It couldn’t fly, which made the dodo easy to catch, and it was hunted to extinction by introduced predators.

Dimetrodon lived about 40 million years before the dinosaurs. Despite its appearance it is not a dinosaur. In fact, it’s more closely related to us than it is to the dinosaurs!

A penguin is a bird and birds are … that’s right, birds are living dinosaurs!

The komodo dragon is not a dinosaur. But it is the largest lizard on Earth today, which is quite impressive.

A peacock is a bird—just look at those feathers—and birds are living dinosaurs.

On the other hand, Champsosaurus is an extinct reptile, but not a dinosaur.

The sabre-toothed cat is a prehistoric mammal. It went extinct about 10,000 years ago.

The emu, however, is a bird and birds are … you guessed it, dinosaurs!

Anatalavis is a prehistoric bird related to ducks and geese. And, of course, because it’s a bird it’s a dinosaur!

On the other hand, Protungulatum is not a dinosaur. It’s an extinct mammal that lived alongside many dinosaurs during the Cretaceous period. Protungulatum is related to modern ungulates—animals with hooves like horses, sheep, deer and hippos.