This Is Why Animals Today Don't Grow As Large As Dinosaurs Did

Evolution can be a cruel mistress.

While there were plenty of dinosaurs that were on the smaller side, many of those we recognize were enormous creatures that dwarf almost all the species of land animals we see today.* 

Since the mass extinction that wiped out the dinosaurs 65 million years ago, animals have been trending on the smaller side. Sure, there have been many large land animals since then, but none standing as tall as our favorite prehistoric beasts. 

So what changed? 

For one, the Earth did.

As DNews explains, the Earth that the dinosaurs lived on was much different than the one we know today. Not only were the continents in completely different positions than they are now, but differences in vegetation and gases meant the air was very different as well. 

Primarily, levels of carbon dioxide were astronomical, even by today's standards with our current climate crisis. Scientists disagree about how that actually affected their size, with a few main theories about food availability and body temperature. But after the mass extinction, new environmental conditions favored other body types.

That said, CO2 levels alone can't explain everything about why dinosaurs were able to reach such incredible heights. They had some handy evolutionary adaptations that contributed to their stature.

So what are the chances that we could see enormous land animals like dinosaurs again?

Find out here:

*The blue whale is not just the largest animal alive now, but likely the largest animal that has ever lived. Many other modern whale species are larger than dinosaurs as well, but when comparing modern land animals to dinosaurs, dinosaurs are the clear winners.

Cover image: Shutterstock