The Evolution of Chickens: What can we learn from chickens' dinosaur ancestors?
While it’s hard to imagine when looking at a Silkie, chickens are not just descended from dinosaurs. They are dinosaurs!
As crazy as it sounds, scientists agree that birds are a dinosaur species that survived the mass extinction. Since then, they have continued evolving and populating the globe.
While there are different theories about how birds evolved, why they survived, and how closely they resemble other types of dinosaurs, birds are living dinosaurs.
What evidence is there that birds are dinosaurs?
For a long time, people thought dinosaurs were closely related to reptiles. But since the 1960s, scientists have become convinced that dinosaurs are more closely related to birds than reptiles. There is even some genetic evidence to support this theory!
One study found that from 21 living species, the chicken and the ostrich had the most similar collagen to a Tyrannosaurus rex! Although this study has been questioned, similar results have been found by other scientists too. A more recent experiment showed that gene manipulation could create a chicken with a dinosaur-like snout, in the egg at least!
Other evidence of the link between dinosaurs and birds includes:
- Many dinosaurs walked on two legs and had a similar pelvic structure to birds
- Dinosaurs laid eggs and some species cared for their young in nests
- Certain dinosaur species had hollow bones, beaks and even wishbones!
- Some dinosaurs had feathers and we have even found fossilised dinosaur feathers!
- The Mei Long fossil shows a dinosaur sleeping with its head under its wing, just like a chicken!
Plus, have you ever watched your chickens run? They're totally channelling the Velociraptors in Jurassic Park!
How did birds evolve from dinosaurs?
Like mammals today, there used to be many different types of dinosaurs. Some were large, others small. Some were carnivorous and others ate plants. It’s no surprise that there were so many, given that dinosaurs ruled for 170 million years!
One group of dinosaurs, called the Theropods, includes the ancestors of today’s birds along with famous dinosaurs like the T. rex and the Velociraptor. The Archaeopteryx fossil is an example of a Theropod and one of the most bird-like dinosaur fossils we have found.
Birds (Aves) are a Family of Theropods, so the equivalent of Hominids, which includes humans and the great apes, in today’s mammals.
Birds survived the mass extinction of dinosaurs. Since then, they have evolved so much and formed so many new species that they have become their own Class of animal!
Why did birds survive the dinosaur mass extinction?
Amazingly, birds are the only type of dinosaur that survived the mass extinction caused by an asteroid 140 million years ago!
How closely related are chickens and dinosaurs?
Even though we don’t have a complete fossil record, scientists are convinced that all birds are descended from dinosaurs. So just as humans are mammals, chickens are dinosaurs. In fact, your chickens are the great-great-great… grandchildren of a dinosaur!
Even more interesting, a 2014 study suggests that chickens and turkeys could be the bird most closely related to its dinosaur ancestors!
What can we learn about chickens from their dinosaur ancestors?
Scientists have learned a lot about dinosaurs from chickens. One study even tried to understand how a T. rex moved by using chickens with fake tails!
But what can we learn about chickens from their dinosaur ancestors? Don’t underestimate them!
Understanding their past helps us understand our chickens' omnivorous diet and hunting instinct. If you’ve ever seen your flock in the middle of a pecking order brawl, going after a mouse, you will know that chickens aren’t that different from their Velociraptor relatives!
So don’t underestimate your chicken's resilience or their survival instinct. They are just feathered dinosaurs, after all!
Happy chicken keeping!
Rachael at Dine a Chook Australia