The Peta Association joked about the descent connection between the chicken and the terribe Tyrannosaurus Rex on Twitter. The opportunity for paleontologists to deny this common idea and to reestablish the true lineage of hens.
“Think twice about ordering a chicken sandwich… The T-Rex wouldn’t approve of you eating their descendants”, launched the animal rights association Peta on Twitter Thursday, June 1. A tweet seen six million times on the social network which caused a lot of reaction, mainly meat eaters taunting the association, but also paleontologists who stepped up to the plate to restore a scientific truth: no, chickens do not descend from T-Rex.
Think twice before ordering that chicken sandwich… T-Rexes wouldn’t approve of you eating their descendants 👉 https://t.co/cxlUXI2HhY #DinosaurDay pic.twitter.com/GauRbTwjju
—PETA (@peta) June 1, 2023
An old common ancestor
Chickens and T-Rex are actually very, very, very distant cousins and, as Vincent Reneleau, volunteer paleontologist at the National Museum of Natural History in Paris, pointed out to franceinfo, we are not descended from our cousins, we have just a common ancestor. In this case, the common ancestor of chickens and T-Rex goes back a very long time.
In the 2nd degree (but I’m afraid it’s 1st degree😬), the message is funny, but it’s doubly wrong:
– current birds are not descended from T. rex
– T. rex themselves probably ate the ancestors of today’s birds!And it’s spelled T. rex, not T-Rex(es)! https://t.co/ibu9oxaFrP
— Vincent Reneleau 🦕 (@VincentReneleau) June 4, 2023
A scientific study published in the PalArch Journal of Vertebrate Paleontology in 2015 presents a kind of family tree that helps to better understand the error. Chickens and T-Rex belong to the large family of theropods, two-legged dinosaurs, which appeared about 235 million years ago. Over the centuries, this family split into several branches, and about 180 million years ago the coelurosaur branch appeared, literally “hollow-tailed lizards”. It is the last common ancestor of T-Rex and Chickens.
A few million years later, the coelurosaurs in turn split into two branches, long before T-Rexes and chickens existed. On the one hand, this appeared the line of Tyrannosauroids, which would give rise to the T-Rex tens of millions of years later and, on the other side, there was the line of Maniraptoriformes, winged dinosaurs and feathered, which will give birth to all the birds we know today, including chickens. It is the only branch of theropods that is still active today.
A frequent misinterpretation
The error made by Peta is quite common in popular science. To support its point, the association shared an article from the Guardian of 2008 on a study which was able to prove thanks to a molecular analysis that the hens and the T-Rex had a bond of “kinship”. This confirmed the intuitions that specialists had had for decades after visually comparing their skeletons.
When it came out, this study received wide media coverage and, as Peta did a few days ago, shortcuts, even misinterpretations, were often made. This gave several press headlines saying that the hens were descended from the T-Rex, when it was only a simple relationship, very old and distant.
In summary: hens and T-Rexes have a common ancestor as we sometimes have distant cousins, but hens do not descend from T-Rexes, which died out without any heirs.