Are crocodiles dinosaurs?
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Dinosaurs and alligators lived at the same time and share a common ancestor. But are crocodiles dinosaurs?
Crocodiles are not dinosaurs, although they once belonged to the same order as dinosaurs. Their ancestors were closely related to dinosaurs while walking the earth.
When the dinosaurs became extinct, the ancestors of crocodiles continued to evolve into the crocodiles we see on Earth today. They haven't even changed much since the Mesozoic.
In this article, we'll discuss why alligators aren't considered dinosaurs, the relationship between the two, and how alligators evolved (and didn't) over time.
What Are Dinosaurs: Do They Exist Today?

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Dinosaurs are extinct reptiles that lived in the Mesozoic Era. They belong to the order Archosaurs, which includes pterosaurs, dinosaurs, and crocodiles.
Dinosaurs shared many characteristics with crocodiles, including being cold-blooded, laying eggs and having a similar skull shape. Both dinosaurs and crocodiles are reptiles.
Because dinosaurs are extinct by definition, we only know about them from fossils. No extant (or still living) creatures are considered dinosaurs, even if they existed at the same time as dinosaurs.
Are crocodiles dinosaurs?
To sum up, we can conclude: no, crocodiles are not dinosaurs.
We know they are modern creatures, not fossils that we have dug up and pieced together over time.
However, they are closely related to dinosaurs and lived in the same era. The alligators we know today are not that different from their ancestors either!
Another interesting consideration: If alligators went extinct at the same time, would they be considered dinosaurs?
If alligators went extinct, we'd probably think of them as dinosaurs and lump them together!
There is no difference between the way scientists distinguish crocodiles from dinosaurs today, in part because we know more about crocodiles now that we have been able to witness them.
Master Dragons: Prehistoric Creatures of the Period

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Archosaurs are prehistoric creatures belonging to the order Archosaurs . They can be divided into three groups:
- Pterosaurs were flying reptiles.
- Dinosaurs were a diverse group of reptiles that included the bipedal, short-armed Tyrannosaurus rex, spinosaurus, and long-necked brontosaurus. All these animals are now extinct.
- Alligators are the group that includes crocodiles and alligators. Some species have become extinct, but two crocodiles, two crocodilians, 17 crocodile species and six caiman species still exist today.
The only archosaurs alive today are birds and crocodiles. This means that birds and alligators are closely related to each other despite their huge differences!
They're also the closest living relatives of dinosaurs — though they weren't dinosaurs themselves.
Today's Crocodiles vs. Prehistoric Crocodiles

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Most living things evolve slowly over time, and we can see huge differences between the animals we know today and their ancestors millions of years ago.
However, alligators seem to have been perfectly designed – as they haven't changed much in the 80 million years they've lived on Earth!
If you could see the ancestors of today's alligators, you'd recognize them instantly. Not only that, but scientists have found evidence that species today may be much older than we originally thought.
We don't know why the ancestors of crocodilians survived the extinction of the dinosaurs, but they may simply have been more adaptable.
Evan Whiting, who has published several studies on crocodiles, believes their ability to adapt may be why they are in trouble today.
When humans enter crocodile habitats, we see them climbing fences, swimming in swimming pools, and not having a good relationship with humans—whether it’s human hunting or crocodile attacks.
Whiting believes that understanding alligators can improve our relationships and lead to peaceful coexistence, which includes protecting alligator habitat rather than taking over or destroying it.
Plus, today's alligators face another adaptation challenge: climate change. It is thought that crocodiles may begin to migrate north as the natural environment changes and northern areas become more habitable. For now, frigid northern temperatures keep them from venturing too far.
Brachychampsa: The first crocodile species
The first crocodile species was called Brachychampsa. They are about 8-10 feet (2.5-3 meters) long and have powerful jaws with rounded teeth adapted to eat shells.
Thanks to studies of their jaws and teeth, researchers believe the crocodile ate turtles.
This is not dissimilar to today's crocodiles, which ate turtles along with fish, birds, snakes and small mammals.
Today's crocodiles, however, have sharper teeth and weaker jaws—although they still have a jaw-dropping force of over 2,000 pounds per square inch!
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I'm an animal writer for four years with a focus on educational pet content. I wish our furry, feathered and scaly friends the best care! In my free time, I'm usually outside gardening or spending time with my nine rescue pets.
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