Yes — birds are dinosaurs!

More specifically, birds are the direct descendants of a group of theropod dinosaurs, which includes famous species like Tyrannosaurus rex and Velociraptor. In fact, modern science identifies birds as the only living dinosaurs today.

🦖 How Is That Possible?

Here’s how it works:

  • Dinosaurs were a diverse group of reptiles that lived millions of years ago.
  • They split into two main groups: ornithischians (like Triceratops) and saurischians.
  • Within the saurischians were the theropods, which walked on two legs and were often fast and predatory.
  • Over millions of years, a small group of feathered theropods evolved into early birds during the Jurassic period.
  • Archaeopteryx, often called the first bird, is a famous transitional fossil that shows both dinosaur and bird features (like feathers, teeth, claws, and a long bony tail).

🪶 What Links Birds and Dinosaurs?

Modern birds share many features with their dinosaur ancestors, including:

  • Feathers
  • Hollow bones
  • Laying eggs
  • Three-toed limbs
  • Wishbones (furculae)
  • Similar lung and respiratory systems

These similarities are so strong that paleontologists now classify birds within the dinosaur family tree. They belong to a group called Avialae, which falls squarely within Theropoda branch of the dinosaur family tree.

🐦 So… Are Chickens Tiny T. rexes?

In a way, yes! Chickens, pigeons, ostriches—every bird you see today is a modern, living dinosaur. While they’re obviously very different from something like T. rex, the evolutionary line connecting them is clear.

Ranger David, who has many birds of prey in his Animal Club gives us insight:

Birds evolved from a branch of theropod dinosaurs during the Jurassic period, around 150 – 165 million years ago. Many features we associate with birds today—such as feathers, hollow bones, and air sacs—were actually shared by numerous non-avian dinosaurs as well. There is evidence that smaller relatives of triceratops had quill like feathers on the back and tail, and sauropods like brachiosaurus had a network of airsacs throughout their body. Most theropods were fully covered in feathers, and animals like Velociraptor likely resembled long-tailed, flightless hawks rather than the scaly, bipedal lizards depicted in Jurassic Park.

The line between birds and dinosaurs is not clear, with many species like archaeopteryx and microraptor showing features of both groups. These animals were fully feathered, with large wings and fan-like tail feathers that allowed them to glide and flutter between trees. However, they still retained long, bony reptilian tails, clawed fingers, and jaws lined with sharp teeth. The first birds that closely resemble modern species appeared during the late Cretaceous period, shortly before the mass extinction that wiped out all other dinosaurs, along with three quarters of life on earth. They are the only group of dinosaurs that survived.

Ranger point of view:

Whether you consider birds to be dinosaurs depends on your point of view. They are undoubtedly descended from dinosaurs, but are birds now different enough to be considered their own group? It’s a fair question—modern classifications were designed for modern animals, and we often treat birds and reptiles as separate categories. Yet, biologically, they clearly evolved from reptiles and, more specifically, from theropod dinosaurs. So while birds form a distinct and highly specialized group, they still fall within the reptile lineage, not outside of it. In evolutionary terms, birds are reptiles—and more precisely, they are the last surviving dinosaurs.

Personally, I do consider birds a type of dinosaur, but by the same logic I would also consider snakes a type of lizard. Despite reptiles often being thought of as ancient, prehistoric animals, birds are actually much older than snakes.

More from Ranger David:

The feet of Syrus, my Harris’ Hawk. Seeing this leaves little doubt that birds are dinosaurs. The reptilian scales are obvious, but notice the enlarged sickle claw on the inside toe, used in exactly the same way as their dromeosaur cousins would have to pin down and hold onto prey. Dinosaurs like Velociraptor and Deinonychus are well known for this trait—fittingly, the name “Deinonychus” literally means “terrible claw,” highlighting this distinctive feature.

In Summary

Birds are dinosaurs—the only branch of the dinosaur family tree that survived the mass extinction 66 million years ago. So the next time you see a robin, crow, or parrot, remember: you’re looking at a tiny, feathered dinosaur still ruling the skies.

Last Updated on June 3, 2025 by Author