How are birds like dinosaurs?
Evolution of birds timeline
How did birds survive the extinction of the dinosaurs?
What bird is most closely related to dinosaurs?
Birds are one of the most successful groups of animals on Earth today. Depending on the time of day, you may see or hear birds anywhere you read this! It seems almost unbelievable that these busy bipedal flying creatures could be related to the large scaly dinosaurs we see in books and movies.
Birds aren’t just related to dinosaurs, they’re technically dinosaurs. More than 150 million years ago, the first birds evolved from theropod dinosaurs. Their evolution was not a single event, but a gradual process of adaptation and mutation involving many species that became more and more bird-like.
Paleontologists and ornithologists agree that birds lived alongside dinosaurs before the mass extinction event 66 million years ago, and were the only ones to survive the catastrophe. Simply put, birds are a group of living dinosaurs!
The first flying reptiles were pterodactyls. They’re not technically dinosaurs, and have nothing to do with the evolving birds they’ve shared on Earth for millions of years. Theropods looked very different from modern birds. However, they also share many undeniable similarities.

Illustration of a Pterodactyl, commonly known as Pterodactyl
Some dinosaurs developed feathers and small wings long before they gained the ability to fly. But why would dinosaurs give up arms for wings that couldn’t sustain flight?
Flight may have evolved in dinosaurs in some surprising ways. Research from the University of Montana shows that even stunted wings can be useful.
For example, ground birds can run on near-vertical surfaces without actually flying. Other examples include ducks that can use their wings to move faster across water, or chicks that can jump from heights to the ground by using their wings to parachute and coordinate their landing.
Read on to learn more about how birds evolved to become what they are today and how they survived the asteroid that killed all the other dinosaurs.

Tufted ducks flying low over the water
How are birds like dinosaurs?
Birds evolved from a suborder of two-legged dinosaurs known as theropods.This group of dinosaurs contains well-known species such as Tyrannosaurus rex and Raptor.
Birds are technically modern dinosaurs and thus share many characteristics with their extinct ancestors. Some of the most striking similarities lie in the structure of hands and feet, metabolism, gait, and even the presence of feathers.
Let’s look at some of the things that dinosaurs and modern birds have in common:
passionate
Dinosaurs were considered warm-blooded (warm-blooded animals), like modern birds today. This differs from reptiles, amphibians and fish which are usually cold-blooded (ectotherms).
biped
Birds are bipedal, which means they walk, run and jump on two legs like us. Theropods were also bipedal, although many other groups of dinosaurs walked on quadrupeds.
feather
Some theropods even had feathers, though they couldn’t fly. Feathers have excellent insulating properties, so they may have been developed to keep dinosaurs warm. However, their plumage does not necessarily cover the entire body, and is usually limited to the tail and forelegs. Dinosaur feathers also had a display function in some cases, used to attract mates or intimidate rivals.
foot structure and hand structure
theropod dinosaur like Tyrannosaurus rex There are three forward toes and one backward pinky. Sound familiar? That’s because most modern birds have the same arrangement. The pod sac, the scaly covering on the feet of birds, also first evolved in theropods.
Although theropods may not have wings, their forelimbs bear a clear resemblance to the wings of birds. Later theropods also had only three fingers on their hands, just as modern birds have three fingers on their wings.
special bones
Theropod dinosaurs also had hollow bones and wishbones (wishbones), like modern birds do today.

Foot structure is one of the greatest similarities with dinosaurs
Evolution of birds timeline
Birds as we know them today did not evolve overnight. Selection pressure from competition with other animals, their surroundings, their food sources and other factors have shaped them over hundreds of millions of years of natural selection and evolution.
Our insights into their evolutionary progress come largely from the fossil record. Here are some major milestones in the evolution of birds:
- 230 million years ago: edromanthe first known theropod to hunt in modern-day Argentina.
- 150 million years ago: Archeopteryx lithographthe dinosaur that many believe was the first bird, flew over the forests of present-day Germany. archeopteryx There’s a long tail and a mouth full of teeth, but it’s undeniably birdlike.
- 120 million years ago: Confucius bird, the earliest toothless bird lived in present-day China. It was about the size of a crow and looked very much like a modern bird.
- 66 million years ago: Chicxulub Crater was formed when an asteroid about 6 miles in diameter hit Earth from Mexico’s Yucatan Peninsula. Some birds survived the impact and aftermath, but all other dinosaurs went extinct.
- exhibit: Birds have differentiated (evolved) into 10,000 to 18,000 species of birds. They didn’t grow to the size of other extinct dinosaurs, but were a very diverse and successful group of animals, present on every continent and in the skies and seas.

Archeopteryx, a late Jurassic bird-like dinosaur about 150 million years ago
How did birds survive the extinction of the dinosaurs?
About 66 million years ago, a massive asteroid slammed into the ocean near Mexico’s Yucatan Peninsula. This asteroid strike is known as the Cretaceous-Paleogene (K-Pg) extinction event.
Dust kicked up by the impact smothered and killed plants, the base of the food chain. Dust clouds hung in the sky, blocking sunlight and cooling the ground.
Up to 75 percent of species are thought to be extinct, but some birds have found a living in this inhospitable wasteland. These avian dinosaurs are the only ones that survived.
The vast majority of bird-like dinosaurs went extinct, as did many of their species—the pinnacle of millions of years of evolution. However, some ground and water birds did survive.
We don’t know why birds were the only dinosaurs to survive the K-Pg extinction event, but the following factors may provide an answer:
- Birds were small and reproduced and reproduced faster than non-avian dinosaurs.
- Birds can survive on little food. This is important when resources are scarce.
- The birds are highly mobile, which means they can forage at greater distances and move out of the hardest-hit areas.
- Birds have adapted to eating a variety of different food types. Fresh plants, insects, and small animals will become very scarce, but the seeds will persist, providing a very long-lasting food source that birds can utilize.

Cretaceous-Paleogene (K-Pg) boundary of Zumaia (Spain)
What bird is most closely related to dinosaurs?
Not only are modern birds closely related to dinosaurs, they are technically dinosaurs too. The mass extinction event that occurred about 66 million years ago wiped out all non-avian dinosaurs, as well as most of the birds that survived at the time. All modern birds evolved from those few survivors, and there are more than 10,000 bird species on Earth today.
However, some birds do indeed look more primitive than others. This topic is a great conversation starter because it’s entirely open to interpretation, but the following birds certainly look pretty close to the classic description of a dinosaur:
- bald eagles and bald eagles -The large size and bare head and neck of these birds make them look very much like dinosaurs. The California condor and the vertical-faced condor are good examples.
- Cassowaries and other ratites – Many of these giants of the bird world have bare heads and necks, walk upright on two legs, and lack the ability to fly. If you squint your eyes a little, they look just like modern theropods! Interestingly, these ground birds evolved from flying birds.
- Hoatzins – These lumbering South American birds have no face feathers. Adults can fly, while larvae use the well-developed claws on their wings to climb across branches.

Close-up of a perched California Condor
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I am broadly interested in how human activities influence the ability of wildlife to persist in the modified environments that we create.
Specifically, my research investigates how the configuration and composition of landscapes influence the movement and population dynamics of forest birds. Both natural and human-derived fragmenting of habitat can influence where birds settle, how they access the resources they need to survive and reproduce, and these factors in turn affect population demographics. Most recently, I have been studying the ability of individuals to move through and utilize forested areas which have been modified through timber harvest as they seek out resources for the breeding and postfledging phases. As well I am working in collaboration with Parks Canada scientists to examine in the influence of high density moose populations on forest bird communities in Gros Morne National Park. Many of my projects are conducted in collaboration or consultation with representatives of industry and government agencies, seeking to improve the management and sustainability of natural resource extraction.