Are Alligators Dinosaurs? The Truth About These Ancient Reptiles

Alligators are massive reptiles that strongly resemble the dinosaurs we all love to imagine and learn about. But are they really related? Could alligators actually be the modern version of living, breathing dinosaurs?

Alligators are not technically dinosaurs. However, they are descended from crocodilian species that once lived among the dinosaurs. Because alligators are so adaptable, their evolutionary history is remarkably steady and could explain how their ancestors withstood prehistoric mass extinction.

You may be disappointed with such a blunt answer, but keep reading. You may yet be surprised at what you learn about alligators’ fascinating evolutionary history.

Did Alligators Evolve From Dinosaurs?

Did alligators evolve from dinosaurs?

Alligators evolved from archosaurs, one of three major classes of dinosaurs during the Triassic period, which occurred about 250 million to 200 million years ago. Archosaurs, also known as “ruling reptiles,” are the massive, reptilian ancestors of a wide range of modern reptiles, including all alligators, crocodiles, and even many birds.

Archosaurs began to appear during the Middle Triassic Period, evolving from what are prehistoric diapsid reptiles. Diapsids are characterized by having two openings in their skull, right behind each eye, as well as short front legs and long back legs.

Their teeth are set in sockets, and their skull tends to have a snout-like opening near the base of the eyes. Typically, diapsids are recorded as laying eggs when they mate, but some species give birth to live young.

A major distinguishing characteristic of archosaurs is locomotion, or how each species has evolved to be able to move around. Crocodilian species evolved to have flexible ankles that allow each leg to twist as needed when the creature walks.

This is not only a defining physical attribute, but it’s also evolutionarily necessary for a reptile whose body is so incredibly close to the ground. If a reptile with this kind of ankle wants to walk more quickly, it can lock the ankles in place for the added advantage of slightly higher elevation.

With versatile features like these, the alligator has a long history of being adaptable to changes in the environment. It survives even the most dramatic changes in climate, sea level, and topography. It’s also why the alligator so strongly resembles some of its more recent, though still ancient, ancestors.

A scientist who specializes in the study of alligators recently discovered an ancient skull that almost exactly resembles the skulls of alligators alive today. This ancient skull indicates that the alligator species has been largely untouched by evolutionary changes for up to 8 million years!

Alligators Have A Different Skeletal Structure Than Dinosaurs

Most land dinosaurs fall into either of two categories: two-legged and four-legged. Each category contained a wide array of diverse reptilian species, but, for the most part, their legs shared the same vertical joint design. One of the reasons that alligators do not classify as dinosaurs in our world today is that their skeletal structure differs so completely from that of their archosaur ancestors.

The Teleocrater, a prominent alligator ancestor, strongly resembled what we would recognize as alligators today. It was between 6 and 10 feet long, 20 and 65 pounds heavy, had a long, thick tail, and had powerful clamping muscles at the back of its jaw. Compared to more birdlike archosaurs, the Telocrater walked with a low, wide stance.

The main difference between Telocraters and modern alligators is height, due to variations in leg structure. Scientists estimate that Telocraters was about two feet tall since their four legs were secured mostly beneath their torsos.

Today, alligators’ legs are in a wide, outstretched stance, situated horizontally rather than vertically beneath their bodies. From this distinction and many others, we can tell that alligators did indeed evolve from archosaurs, but that they have also changed so much over the millennia that they are no longer the same species.

So yes, alligators have a strong evolutionary and historical correlation with ancient species, but remember: Dinosaurs lived up to 250 million years ago. Even compelling evidence like a skull that is 8 million years old is not sufficient enough to indicate that alligators’ genetics date all the way back through the fossil record to the Jurassic period.

The resemblance is striking and the history is fascinating, but the reality of alligators’ evolutionary distinction all comes down to their current skeletal structure. Above all other species, there’s one reptile that’s even more closely related to dinosaurs than alligators are. It’s called the Tuatara.

The Tuatara Lived Amongst The Dinosaurs

You may be wondering whether other reptiles such as lizards are dinosaurs? They are, after all, seemingly our closest living visualization of what the enormous reptiles must have looked like millennia ago. But the Tuatara easily surpasses all other reptile species in how closely it resembles its ancient ancestors.

Tuataras have been around for over 250 million years, and yes, that’s exactly how long ago dinosaurs lived. Native to New Zealand, these reptiles are particularly elusive.

Their grey, green, and brown colors allow them to blend in easily with their environment, but survival has not always been easy. Though at first glance you might think the tuatara is a lizard, it is actually a different species altogether.

Though it is debated among paleontologists and biologists whether or not this creature truly is a “living fossil,” the general consensus is that, regardless, Tuataras must be protected and preserved. Thanks to Zealandia, the Karori Wildlife Sanctuary, species like the Tuatara have been brought back from levels of borderline extinction.

This haven is home to hundreds of precious creatures and critters and is a major tourist attraction. So if you ever find yourself in New Zealand, stop by and say hello to the world’s oldest reptilian species!

Even though alligators are not technically dinosaurs, it’s pretty amazing that so many prehistoric species have managed to survive this long on the planet. From sea turtles and sharks to birds and lizards, traces of the past are all around us, here in the present. As long as we conscientiously observe and preserve the inhabitants of this planet, we can continue to enjoy existing with and learning all about them.

Are Any Dinosaurs Alive Today?

The answer to that question depends on who you ask. To many scientists, the answer is yes, there are dinosaurs living today. These “living dinosaurs” roam the earth in large numbers, defy the forces of gravity, and live in bushes, burrows, and trees. Some of us even have them for pets.

Where are these “living dinosaurs,” you ask? Why, they’re everywhere. And you’ve definitely seen many of them yourself! What are they?

They’re birds.

Birds and dinosaurs share a remarkable level of genetic similarities, right down to nearly identical DNA gene sequences. Scales and feathers aren’t so different, in terms of evolution and biological properties. In fact, some paleontologists believe that theropods, or dinosaurs with three-toed feet, like the T-Rex and the Velociraptor, were actually coated in feathers.

Chickens Are Closer To Dinosaurs Than Alligators

Sure, we depict dinosaurs in drawings and diagrams as larger-than-life, scaly beasts, but feathers cannot be preserved in the geological record over time, so there’s no way to prove that dinosaurs weren’t covered in feathers that simply dissolved after their mass extinction.

“In the view of most paleontologists today, birds are living dinosaurs. The traits that we accept as defining birds—key skeletal features as well as behaviors including nesting and brooding—actually arose first in some dinosaurs. Most intriguing, and debated, is the evidence of feathers and featherlike structures on these dinosaurs…

The best explanation for the presence of these shared characteristics is that they existed in a common ancestor, from which both dinosaurs and birds are descended. As more fossils help fill in gaps in the bird-dinosaur family tree, scientists are reassessing their understanding of the origin of birds and acknowledging that the boundary is blurred between modern birds and their dinosaur ancestors.”

American Museum of Natural History

Since the 19th-century discovery of the Archaeopteryx, a feathery, bird-like dinosaur, paleontologists have worked tirelessly to bridge the gap between reptilian and avian species. Eager to learn more, they discovered that the Archaeopteryx, unlike any other bird, had grasping fingers on the joints of its wings and a long tail extending from its back. And unlike most other dinosaurs, it could fly. Some people believe that this was the first bird to have evolved on Earth.

Ever since this discovery, scientists have grown increasingly confident that birds are descended from dinosaurs. Even their eggs share a striking resemblance, and the way that they mate and lay eggs appear to be similar as well. So the next time you see a robin in its nest, a pigeon strutting down the street, or a magpie soaring over the fields, just remember that these diverse, winged creatures could be our closest connection to the dinosaurs that once roamed the Earth.

Which Species Are Related to Dinosaurs?

Besides alligators, there are a few animal species alive today that bear modern resemblance to, or ancestral connections with, dinosaurs. Some of these will completely make sense; others might surprise you:

  • Chickens: That’s right. The feathered farmyard friend we all know and love shares a significant amount of DNA with dinosaurs, specifically the Tyrannosaurus Rex. It might seem impossible to believe, but the world’s oldest and most dominant predator now exists in genetic fragments among all bird species. Two-legged dinosaurs, or theropods, are much like birds, especially because the genetic sequences for scales and feathers are incredibly similar!
  • Sea Turtles: The beloved, shelled icons of the ocean, sea turtles belong to the Archelosauria group. This means that their ancestors evolved in the water during the Jurassic period when dinosaurs roamed the earth. About 110 million years ago, a massive turtle called the Archelon dominated the seas; this underwater dinosaur was 4 meters long and 5 meters wide! Today, sea turtles aren’t nearly that size, but their shell structure and fins, designed perfectly for underwater cruising, are evidence of a long evolutionary history, interwoven with dinosaur connections.
  • Lobsters: If you think about it, lobsters and crabs are basically giant, underwater bugs. Yum! Fossil records indicate that these creatures have ancestral links to all kinds of massive, prehistoric crustaceans. They’ve been around this long, and it doesn’t look like they’re going anywhere any time soon!
  • Ostriches: Did you know that ostriches have roamed the Earth for over 66 million years? That’s not much compared to how long ago dinosaurs lived, but when you look at their gangly bodies and vicious talons, it isn’t hard to imagine the fact that they’re related to velociraptors. These enormous birds continue to thrive in even the harshest conditions, which may explain why they’ve lasted this long!
  • Snakes: Not all dinosaurs are giants. In fact, they don’t even have to have legs. Snakes have been around twice as long as the T-Rex, according to our fossil records. Tracing their ancestors back to long, fossilized vertebral bone structures, these strong, slithering reptiles continue to be one of Earth’s hardiest species today.

All of these species, and many more, collectively prove that Earth is an ever-changing sphere of wonder. As species evolve and adapt to the environment, we can be sure that many of them bear resemblance to the first signs of life on this planet. Many dinosaur-related creatures are endangered; it would be a shame to lose them after all of this time, so it’s worth learning whatever we can to spread awareness about their ways of life.

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