This is just my take on it, purely speculative and not based on any expertise on zoology, cosmology, or creation science:

Dinosaurs are no more than reptiles which were placed in the atmosphere most optimum for their flourishing, hence their attained sizes and seeming pre-eminence as a species. They require a hot, dry environment to maintain, but this environment ended as a result of the ice age (which, in my belief, came as a result of the Genesis 7-8 flood). I believe that The Holy Bible DOES acknowledge their existence but uses different nomenclature (Leviathan and Behemoth rather than mosasaurus or brontosaurus or Tyrannosaurus rex).

Non-believers have exploited the findings of certain fossils, paired with the seeming silence of believers concerning these creatures, and have championed their presence to an exaggerated extent, believing that dinosaurs render any Creation account obsolete fairy-tales. 

I don’t know where the foremost apologist of the Faith C.S. Lewis fell in this debate (I have no doubt that many on this website know very well), but my thinking is that for these children’s tales he just didn’t want to bother with it. But, Jasmine, I personally think it would have been cool to have a big dumb T-Rex in one of the books. 

Posted by: @reshpeckabiggle

I personally think it would have been cool to have a big dumb T-Rex in one of the books. 

That would've been interesting. Although I don't think it would go around and eat people like it does in Jurassic Park.

The closest thing to canon Narnian dinosaurs that I can think of were the sleeping reptiles that woke up at the end of the world and helped bring it about.  Of course, they were much more likely to be of the dumb variety, as they didn't enter Aslan's country afterwards. 

I don't know what Lewis's personal view on these issues was; I haven't read many of his writings apart from the Chronicles and I don't know if he ever mentions evolution or prehistoric life forms. But he was an Anglican, and the Anglican Church has certainly never made it a requirement of faith that every word in the Bible must be taken as literal fact (creation happening in seven literal 24-hour days, only a few thousand years ago, all living things appearing instantly in their current forms, Adam and Eve as actual persons rather than allegorical figures, etc.). In fact, the majority of Christians worldwide don't take that stance, or certainly don't see any major conflict between science and their faith, so I somehow doubt Lewis did. (And I'm guessing that if he did have very strong feelings on this matter, he would have written about it.)

That said, in The Magician's Nephew we do see Narnia being created all at once by Aslan (not in a series of days, though), with all the creatures emerging fully formed from the ground. But it's a totally separate creation from our world; it didn't begin at the same time and it doesn't end at the same time. And Lewis doesn't mention dinosaurs, or any other prehistoric beasts, as among the animals that Aslan calls into being. The two largest creatures that spring from the earth on that first Narnian day are elephants! (Not that all dinosaurs were huge; many weren't.) So if he doesn't portray dinosaurs as ever existing in Narnia, at the beginning or later, then they didn't. I really don't think it would add anything to the story to have them there, either; that wouldn't contribute anything important to the plot and would just look like a cheap gimmick (Narnia goes Jurassic Park?) that's totally out of step with what Lewis was wanting to portray.

I guess anything is possible in the world of Narnia.

According to the Narnian timeline, Aslan turned Calormenes in Telmar into dumb beasts for their wicked behavior. So what if dinosaurs were among the dumb beasts?

I think that's how dragons got to be in Narnia in the first place. There's no mention of dragons at the creation of Narnia, so it's most likely when Aslan turned Calormenes in Telmar into dumb beasts, dragons started appearing.

So it may be possible that dinosaurs were among the dumb beasts that Aslan turned Calormenes that settled in Telmar into.

Lewis was a man of his times, and dinosaurs were not a thing of interest back then. 

There was a great surge in interest from 1980s onward, if I remember correctly. I barely knew any dinosaur names until the 1990s (Jurassic Park did not generate any interest in me). It was little boys who were keen on them. Jst once I had to teach a unit on dinosaurs, and found it boring. 

Adding dinosaurs into Narnia would be putting in modern interests. It would be failing to follow the book.

Posted by: @coracle

Lewis was a man of his times, and dinosaurs were not a thing of interest back then. 

There was a great surge in interest from 1980s onward, if I remember correctly. I barely knew any dinosaur names until the 1990s (Jurassic Park did not generate any interest in me). It was little boys who were keen on them. Jst once I had to teach a unit on dinosaurs, and found it boring. 

Adding dinosaurs into Narnia would be putting in modern interests. It would be failing to follow the book.

Good point! I think the word "dinosaur" was first used in 1848. Imagine if a Narnia film or series adaptation was set in the future.

Since dragons were a popular thing in fairy tales, I've changed the topic to "Dragons in Narnia (Dumb or Talking?)"

Dragons are not mentioned in The Magician's Nephew at the Creation of Narnia, so most likely they would have appeared later.

The only mention of dragons we have are Eustace turning to a dragon and the same could have happened to Lord Octasian in Voyage of the Dawn Treader and Jewel telling the story of King Gale slaying the dragon in The Last Battle.

But is it possible that there are any talking dragons as well?