恐竜って英語でなんて言うの？

Any of these answers can be used in English to describe 'kyoryu'.

The word 'ancient' is usually used to describe something that is usually no longer in existence or extinct and lived millions of years ago. It means something that was on earth before human beings existed, and did not cross over time with human species.

Dinosaur is the most common name for the creatures that roamed the Earth billions of years ago. There are many types of dinosaurs and many different eras/periods of dinosaurs, but the general term is always dinosaur. They were technically reptiles and belong to prehistoric times. To describe them, you could say an ancient reptile, like an alligator, crocodile, lizard, Komodo dragon. These are the only animals existing today that resemble dinosaurs.

Dinosaurs are reptiles that are now extinct or no longer in existence.
The dinosaurs are diverse which means there are different kinds of species. Tyrannosaurus rex which we often see as Viains in movies are also knowns are T-rex while Brachiosaurus or what we know as long neck are only two of the famous species we know. Some are herbivores or plant eating, some are carnivores or meat eating, while some are both otherwise known as omnivores. No one is certain as to what their real outside appearances are, because their exostence in this world was only discovered through their fossils or remails.

a dinosaur is a fossil reptile of the Mesozoic era, in many species reaching an enormous size. They are however now extinct .

eg. A dinosaur is a massive reptile!

I hope this helps :-)

The english word for the term "kyoryu" in Japanese would be "Dinosaur" or "Dino" for short term. A "T-Rex" for example is a very well known species of dinosaur which is commonly used in books and television shows.

Dinosaur:
The name dinosaur was given the to very large reptiles that
roamed (walked) the earth millions and millions of years ago.
The Greek name dinosaur literally means "terrible lizard"
because of its resemblance to a lizard.Terrible refers to its
very huge size and its savageness and ferocity.

"Dino" is the informal and casual reference to a dinosaur.

Dinosaur (a fossil reptile of the Mesozoic era, often reaching an enormous size) is an only word suitable for what you look for. For example - dinosaurs supposedly died because of the meteor.

You would like to know what the English word for "kyoryu" in Japanese, is. They were reptiles of the Mesozoic era, they were often very large. They are said to have been wiped out by an asteroid.
Eg "Earth was inhabited by dinosaurs before an asteroid hit the planet."