How did chickens evolve? From dinosaur to jungle fowl, chickens have an amazing story.

Let’s start this story back during the time of the dinosaurs. Yes, our large combed feather legged friends go back that far, to a group of theropods. 230 million years ago it split into two groups: The Ceratosauria and the Tetanurae. Later, the Ceratosauria split into another two groups: the ceratosaurus and the coelophysoids. The coelophysoids was the line that produced the tyrannosaurus rex.

In 2003, a paleontologist named Jack Horner found a 68 million year old T. (tyrannosaurus) rex fossil in Montana. (US) It was a thigh bone, and inside it scientists found a blood vessel. Even though it was almost 70 million years old, they were able to analyze it and learned, genetically, the chicken is the closest living relative of the T. Rex.
So, does that mean that we have a bunch of little feathered dinosaurs running around our backyards? Does that mean whenever a chicken comes begging for a treat on our poop stained porch I give a theropod a sprinkling of yummy oatmeal? In a way, yes, I do.

You know what, when they are running they do look a bit like dinosaurs, fluffy butted dinosaurs, but still.

But, it’s not like some T. Rexes just got together, had babies, and they all were chickens. No. Let's look at some more recent ancestors of chickens: Jungle Fowl. It is believed that though the modern chickens’ closest relative is the Red Jungle Fowl (Gallus Gallus), the (average) chickens’ skin color was inherited from the Gray Jungle Fowl, Gallus Sonneratii. Like chickens, Red Jungle Fowl are poor fliers, both have combs, and the roosters have a similar stance, (particularly to the Sumatra)

So, chickens are the closest living relative to the tyrannosaurus rex, and relatives of the Jungle fowl. But there's more.
Today's chickens most likely had multiple ancestors. But, according to scientist Michael Zody, because of a“ long history of interbreeding between wild and domesticated birds (that) has resulted in inconclusive DNA evidence”

But here’s what we do know: chickens originally became domesticated between 8,000 and 10,000 years ago in areas of Asia and India. “Archaeologists have recovered chicken bones from Lothal, once a great port on the west coast of India, raising the possibility that the birds could have been carried across to the Arabian Peninsula as cargo or provisions.” Once domesticated, chickens were used for fighting, food, and even religious purposes. Over thousands of years, chickens began to spread around the world from trade, human migration, and more. Polynesians brought chickens to South America around 1200 A.D. Soon after, the Spanish brought chickens to North America. Over several hundred years, mostly through the popularity of cock fighting, chickens began to spread throughout the Americas.
Chickens have been around forever, in some form at least.

Like all birds they started out as dinosaurs, they are close relatives of jungle fowl, and have spread throughout the world and are thriving. Once wild, once farm animals, now, for many, pets, chickens are amazing birds that have changed immensely during the last millennia.

Smithsonian Magazine