Over time and with meticulous attention to detail and ongoing research, paleontologists have been able to determine more clearly that while dinosaurs of the Jurassic and Cretaceous periods may appear to have more in common with animals such as crocodiles and alligators, they are in fact far closer to modern birds.
Research has found Amino Acids and DNA from Dinosaurs, in particular T Rex, that modern chickens were the animal that shared the most similarities. Making it one of the close relatives of dinosaurs. However the chicken is classified, scientifically as a bird, which makes it not a dinosaur.
This fact has led to significant research that determined that the humble chicken is actually the closest living relative to the Tyrannosaurus rex. At least, that’s what DNA profiling has shown to be true, which gives rise to an important question, are chickens dinosaurs?
On the surface, this question might seem completely ridiculous, but the fact is that, as we mentioned in the introduction, chickens and T-rex dinosaurs do share a great deal in their DNA.
Studies have been conducted in which amino acid sequences from discovered T-rex collagen were compared to a number of modern species of animal. The results showed that it was the chicken that was closer to the T-rex DNA profile than any other animal alive today.
Does that mean that the chicken is a dinosaur? In fact, no it does not. As you may have thought to yourself when seeing this question for the first time, a chicken is a bird, not a dinosaur.
Just as Crocodilians — alligators, crocodiles, caimans, etc. — share some common characteristics and ancestry with dinosaurs but are not dinosaurs, the same can be said for chickens and birds.
We actually have an article on T Rex’s closest relative today on the site which you can find linked here and below.
Even for those who accept that a chicken is not technically a dinosaur, they like to throw around the “fact” that chickens are some kind of relative of the T-rex. This actually is not the case at all.
The confusion surrounding this stems from the fact that both chickens and the T-rex fit into a larger family classification, “Theropoda.” Similarly, alligators and many dinosaurs fit into the “Archosaur” category, which is why people think alligators are dinosaurs when they’re not.
The Theropoda family is made up of many theropods, a very diverse group of animals. Within the Theropoda group is a smaller classification: coelurosauria, which further confuses things and creates false facts about chickens and T-rex because both animals are part of this subgroup as well.
In fact, the main thing that Coelurosaurs have in common is that they have feathers. Research has shown that many theropods had feathers in some form, which is now supported by fossil evidence, too.
Therefore, it’s easy to see where the confusion regarding chicken and dinosaurs’ relationship comes from, but also that the reality remains that chickens aren’t dinosaurs. When we break down the Coelurosauria family further, we get to the bifurcation point, namely the two subgroups Tyrannosauroidea — that of the T-rex, as the name suggests — and the Maniraptorformes, which includes chickens and other birds.
A common ancestry these creatures do share, but as we’ve mentioned in other articles on our blog, a common ancestry does not a dinosaur make. In fact, the split between these above-mentioned subgroups happened all the way back in the Jurassic Period.
Randy’s Chicken Blog has a more novel way of expressing the relationship between a chicken and a T-rex, using candy as an analogy.
- Chickens, eagles, and swans are all kinds of birds, so you can think of them as jelly beans.
- Chickens are lemon, eagles are orange, swans are strawberry, for example. They are different flavors, but share common traits that make them jelly beans, or birds.
- T-rex, on the other hand, is a Snickers bar. It’s part of the candy family, but not in possession of anything like the same number of common traits as the jelly beans do among each other.
So, there’s a relationship, but they’re clearly not as closely related as humans and chimps with their 96-percent matching DNA, and to be clear no one really would suggest humans are chimps, well not seriously anyway. We Split from our common ancestor about 7 million years ago ( can read more about that here) .
The Cretaceous-Paleogene Extinction Event that occurred some 65 million years ago wiped out most of the familiar dinosaur species that we have come to know, but it wasn’t a “total extinction.”
A number of smaller animal species survived, including Crocodilians that eventually evolved into the alligators and crocodiles that we know today, and also smaller theropod species that evolved into the ancestors of the modern chicken.
Modern birds evolved from surviving relatives of the pre-extinction Archosaurs that had already started to show some bird-like features, such as sporting feathers. These smaller surviving feathered creatures spent the following 65 million years following the K-Pg extinction evolving into modern birds, including the chicken.
In fact, the period following the extinction event and recovery saw an explosion of bird species emerging from these smaller surviving groups. Including some that you can be forgiven into thinking were basically dinosaurs, the terror birds. These survived from around 62 million years ago to about 1.8 million years ago and may, only may, have been alive with early humans.
About 115 million years ago, birds had lost their teeth, instead forming toothless bills — their beaks — that we now recognize as a common feature of birds we see around us.
Beaks themselves were a result of bird species losing their need for ripping flesh from dead prey and instead having to peck at the ground to forage for food in a world changed by the extinction event. The once-powerful dinosaur-like jaws rescinded, and beaks grew longer and even more functional and tool like.
The key to properly understanding the evolution of modern birds was the discovery of the first-ever before-seen fossilized remains of a feathered dinosaur in China. It was only then that people began to see that despite the thought that dinosaurs were exclusively reptilian in nature, they actually contained species that were more bird-like, not just in build as was always evident, but also in their feathers.
For some, the technical definitions may be irrelevant and they would like to continue referring to chickens as “modern dinosaurs” as they have been erroneously doing for some time already. The fact is that there is a definite relationship, and for those less interested in scientific accuracy than they are a “cool factoid,” the chicken-dinosaur is too precious and engaging to ignore.
Can we devolve a chicken into a Dinosaur.
Although this sounds like something better suited to a scifi novel or dinosaur movie it is actually still being attempted by scientists at the moment. We take a longer look at his and if dinosaurs will ever come back in the article links here and below but we will explain a little about devolution of chickens here as well.
So we know that a chicken is currently thought to be the closest living relative of a T Rex, and therefore dinosaurs, and with this knowledge and some gene splicing, reverse engineering and adaptation it might be possible to discover what made the chicken evolve into a chicken and stop that happening.
Finding these genes is hugely complex though, and requires years of trial and error. In theory if you can find them and modify them you will be able to revert the chicken to an earlier time. If successful it would not be a dinosaur in the conventional sense, it would a reverse engineered chicken.
This has already been achieved to some degree, Dr Jack horner who consulted on the Jurassic Park movies has been active in the field of reverse engineering as has Bhart-Anjan Bhullar who with his team of scientists were studying the evolution of the beak on birds and created a chicken with what can only be described as the mouth, snouth and palate of a Velociraptor
The ethics of this are debatable but the fact remains that it i clearly possible, but as Ian Malcolm warned in Jurassic Park
How long till they manage to go further back in a chicken’s evolutionary journey, say 65 million years ago, remains to be seen. You can read more about these in the links above and below.
We have a few in a series of articles about other animals that may or may not be related to dinosaurs on the site, some are listed below. Feel free to take a look.
- Are Crocodiles related to dinosaurs?
- Are Alligators dinosaurs
- Are Sharks related to dinosaurs
- Are Turtles related to dinosaurs
- Are Lizards related to dinosaurs
- Is a rhinoceros a dinosaur?
For the moment however, despite being on the family tree chickens are not considered to be dinosaurs and chickens are not close enough members of that family to be seriously considered a close family member, not close enough to even be invited home for christmas, probably for the best considering what we traditionally eat at Christmas!
So, chickens aren’t technically dinosaurs, but they’re not far off, in evolutionary, genetic and other respects. Perhaps further research will bring the connection even close together in the future.
Hi, I am Roy Ford a General Studies and English Teacher who has taught all over the world. What started as a fossil collection became a great way to teach, motivate and inspire students of all ages and all over the world about dinosaurs and from that and children’s love of dinosaurs came the site dinosaur facts for kids, a resource for all ages.