Millions of years ago, massive reptiles ruled our planet, and theropods were among the many dinosaur groups. Members of this family included the T. rex, velociraptor, allosaurus, and countless others. We no longer see these beasts lurking around each corner of the modern world. However, many of us do see daily the modern descendants of dinosaurs—birds! Explore the reason dinosaurs shrank and became birds.
Evolution Required Change
Every species relies on evolution to survive in our ever-changing world, and the same is true for theropods. This group of dinosaurs had to evolve into smaller creatures to access more areas of the earth for food and shelter. Flying from place to place is much more efficient than walking everywhere; flight provides access to higher sites.
Therefore, the primary reason dinosaurs shrank and became birds is because it gave them more opportunities for survival. Theropods had to shrink over millennia, meaning their two legs, snouts, and teeth became shorter. Scientists suspect many changes had already occurred by the time the asteroid hit Earth. Alterations in the species, such as developing the ability to fly and growing more feathers, allowed early birds to thrive as Earth entered the subsequent ice age.
Why’d They Shrink?
A bird the size of a large dinosaur wouldn’t be able to hide in many places to seek shelter. Plus, many massive dinosaurs weighed tens of thousands of pounds, which would make them too heavy to fly. How do we know this? One of the reasons many large birds—such as emus, ostriches, and cassowaries—cannot fly is due to their weight-to-wing ratio. Make this ratio even larger, and flight becomes a more definite impossibility. Therefore, dinosaurs had to shrink to be able to eventually fly.
Did All Theropods Become Birds?
While we say “theropods became birds,” that doesn’t necessarily apply to every species in the theropod family. Most of the theropods who followed this evolutionary route weighed 100 to 500 pounds, taking massive beasts like the T. rex out of the ring. Any dinosaur that couldn’t adapt to the changing world went extinct. Natural selection encouraged early birds to continue becoming smaller, as these avians thrived best—being big was no longer ideal.
Buy Dinosaur Action Figures
Nothing beats a realistic-looking dinosaur action figure, and Creative Beast Studio has a range of options for you! In collections such as our beasts of the Mesozoic Ceratopsian series, you can browse magnificent action figures of creatures that failed to evolve. We also have beloved theropod action figures like the T. rex and velociraptor. Add accurate dinosaur action figures to your collection today!