Ancient Reptiles 101: Origins & Top 15 Species


Source by:Narciso Arellano on Unsplash 

Ancient reptiles are one of science’s most fascinating creatures to study. Their unique and sometimes odd looks tickle the imagination. Their way of living, on the other hand, hooks our curiosity.

In this article, we’ll be indulging both your imagination and curiosity as we take a look at ancient reptiles. We’ll talk about their origins, evolution, species that lived in prehistoric days, and kinds that are still alive today.

We’ll also be tackling your most frequently asked questions about ancient reptiles to satisfy your curiosity. Here are the things you’ll learn in this post:

So if you want to see reptiles in a different light, this article is for you. Let’s begin!

The Origin and Evolution of Reptiles


Source by:  Only Dinosaurs 

When it comes to reptile origins, two things come to mind: the period and the species where it all began. These and your frequently asked questions about the evolution of reptiles like “are birds reptiles?” and “what reptile did humans descend from?” will be discussed here.

The First Reptile Era & The First Reptile

According to Britannica, the first reptile era began during the Late Carboniferous period, around 350 million years ago (MYA).

And the earliest species identified as the first reptiles are the Paleothyris and Hylonomus lyelli. These first reptiles’ origins are from ancient amphibians who became the amniotes from which reptiles evolved from.

So if you’re also wondering, “what were reptiles called?”, you now know them by name. They’re the Paleothyris and the Hylonomus lyelli who were “small lizard-like animals that lived in forested habitats”.  

Now, what’s the significance of the first reptiles? They’re important because those species gave way for other types of reptiles to exist in later years like turtles, dinosaurs, birds, and crocodiles.

This may seem like an oversimplification of the evolution of reptiles. But for our discussion, we’ll keep it short and sweet.

You can read more about the finer details of reptile evolution from Britannica and ThoughtCo. You can also watch the helpful video above about the evolution of reptiles to get a better understanding of it.

Dinosaurs, Birds, and Humans

Speaking of dinosaurs and birds, you’ve probably asked the question, “are birds reptiles?” The answer is yes according to the University of California-Santa Barbara. This is most likely because they descended from the first reptiles mentioned earlier who also gave rise to dinosaurs.

Additionally, birds are also considered feathered dinosaurs by the scientific community according to Britannica. Check out the cool video above from the American Museum of Natural History to get a better grasp of how dinosaurs evolved into modern-day birds.

On the other hand, what about humans? Did we evolve from reptiles too, and if yes, what reptile did humans evolve from? Evidence is still far from being enough to confirm it but new research is making significant discoveries that may prove this to be correct.

But findings like Swiss geneticist Michel Milinkovitch’s discovery of placodes in the Australian bearded dragon’s scales may finally prove or disprove the link between humans and reptiles.

Placodes are cells found in mammals and birds that produce hair and feathers respectively. These were known to be absent in reptiles until his discovery.

More research will be needed to come to a breakthrough though. So the answer to the question, “what reptile did humans evolve from” will have to wait until then.

Awesome discoveries, right? Let’s now check out ancient reptiles from prehistoric days and those who are still alive today to appreciate our newfound knowledge.

The Top 15 Ancient Reptiles


Source by: Adam Ford on Unsplash

We can think of ancient reptiles as the ancestors of today’s reptiles that we’ve come to know and love. Additionally, the 15 species we’ll be placing in the spotlight played a role in the evolution of reptiles one way or another. So in light of those thoughts, we hope you enjoy getting to know these ancient predators in the section below.

Ancient Reptiles #1: Hylonomus lyelli


Source by: Matteo De Stefano/MUSE

Scientific Name: Hylonomus lyelli

Time Period: Carboniferous Period (350 MYA)

Let’s start with the reptile that started it all, the Hylonomus lyelli. As we mentioned earlier, the Hylonomus lyelli was the earliest reptile known to have existed.

Its fossil was first discovered by geologist Sir William Dawson in Nova Scotia, Canada in 1842. It was named in honor of his teacher, the geologist Sir Charles Lyell, who was working with him at the time.

These first reptiles are important because they evolved into the four main reptile groups that gave rise to prehistoric and modern reptiles:

  • Anapsids – tortoises, turtles
  • Synapsids – pelycosaurs
  • Therapsids – the Triassic Period’s first mammals
  • Diapsids – evolved into archosaurs that evolved into dinosaurs. These, in turn, became the avian and marine dinosaurs and the modern crocodiles.

Ancient Reptiles #2: Silvanerpeton


Source by: Dmitry Bogdanov –

Scientific Name: Silvanerpeton miripedes

Time Period: Carboniferous Period (350 MYA)

Next on our list is an early reptiliomorpha called the Silvanerpeton. They’re reptile-like creatures that were aquatic. These may be the creatures from which amphibians and amniotes evolved that eventually became the true reptiles whose earliest ancestor identified was the Hylonomus lyelli. The significance of this is that it gives scientists a better picture of the evolution of reptiles.

Its fossils were first discovered by Jennifer A. Clack in 1994 in Scotland’s East Kirkton Limestone Formation.

Ancient Reptiles #3: Pareiasaurs


Source by: Nobu Tamura

Scientific Name: Pareiasauridae

Time Period: Permian Period (299-251 MYA)

Next in our list of first reptiles are the Pareiasaurs. Pareiasaurs are parareptiles who are the most closely connected ancestor of the turtles, according to the University of California Museum of Paleontology.  

These prehistoric creatures had stocky physical builts, bodies of up to 9.8 feet long, weights of up to 600kg, and hard armor-like plates. They’re characterized by slow and clumsy natures which give us a clue where modern turtles’ natures and physical forms took after.

Contrary to what you might be thinking, Pareiasaurs aren’t dinosaurs. They’re different creatures in the evolution of reptiles timeline whose extinction gave way for dinosaurs to flourish. How these came back in the form of the early turtles in the late Triassic Epoch is a point of interest that scientists are still working on like this study published in Research Gate.

Ancient Reptiles #4: Deinocheirus


Source by: FunkMonk (Michael B. H.)

Scientific Name: Deinocheirus mirificus

Time Period: Late Cretaceous Period (70-66 MYA)

We’re now moving on to one of your favorite ancient reptiles, the dinosaurs! And first up is the Deinocheirus who was the epitome of terrifying-looking arms to scientists for 50 years.

Its first fossils were just that, a pair of sinister-looking arms discovered by paleontologist Zofia Kielan-Jaworowska in Mongolia’s Gobi Desert. But a complete skeleton was finally discovered in 2014 by Young-Nam Lee and his team of paleontologists that revealed what these creatures looked like. They found fossils in Mongolia too.

The Deinocheirus was ostrich-like ornithomimosaurs that had a lean but heavily weighing physique and were nearly as tall as a T. rex. They fed mostly on plants, fish, and small vertebrates despite its terrifying arms that make it seem like it was primarily carnivorous.

Ancient Reptiles #5: Spinosaurus


Source by: Only Dinosaurs

Scientific Name: Spinosaurus aegyptiacus, Spinosaurus maroccanus

Time Period: Late Cretaceous Period (99-93.5 MYA)

This fierce-looking ancient reptile was a water-dwelling dinosaur that scientists believe preyed on ancient crocodiles. The spinosaurus is also capable of living on land too which makes them more formidable predators as animals would have to watch their backs whether they be on sea or land.

Scary, right? Nonetheless exciting! It’s also gigantic, measuring up to 18m in length and weighing about 4000 kg. This makes it one of the biggest reptiles in ancient times on top of being the scariest predator. So if you’re thinking of what type of dinosaur to bring to your next dino-themed party or amusement park, a spinosaurus will be a great choice!

Ancient Reptiles #6: Microraptor


Source by: David W. E. Hone, Helmut Tischlinger, Xing Xu, Fucheng Zhang – Hone DWE, Tischlinger H, Xu X, Zhang F

Scientific Name: Microraptor GUI

Time Period: Early Cretaceous Period (125-122 MYA)

You might be noticing different physical forms as we go about dinosaurs. From ostrich-like and spiny, we now look at dinosaurs with feathers. It’s bizarre and that’s why ancient reptiles pique the imagination of so many people.

A good example of one of the first reptiles who had feathers is the Microraptor. It’s a feathered dinosaur who had long feathers made for flight and had four wings.

Scholars like the ones from Boston University believe the family where the Microraptor came from could be the missing link between birds and dinosaurs. National Geographic also reports the same thoughts and shares that birds evolving from dinosaurs may be possible. And it’s that connection that may explain why birds and dinosaurs like velociraptors share similar physical traits like bone structure and plumage.


Source by: Only Dinosaurs

Watch this video from the Natural History of Museum to understand how birds evolving from ancient reptiles like the dinosaurs could have been possible.

Ancient Reptiles #7: Mary River Turtle


Source by: Clive Thompson on BoingBoing.Net

Scientific Name: Elusor macrurus

Years In Existence: 40 million

Now let’s move on to ancient reptiles who are still alive today. Here’s an odd-looking turtle, called the Mary River Turtle, who’s been in existence for over 40 million years.

It’s an endangered species native to the Mary River in Queensland, Australia. This ancient reptile breathes underwater not through its nostrils but its reproductive organs. This special ability lets them stay underwater for nearly 72 hours.

Ancient Reptiles #8: Giant Tortoise


Source by: Childzy at en.Wikipedia

Scientific Name: Aldabrachelys gigantea (Aldabra), Chelonoidis nigra (Galapagos)

Years in Existence: 55 million years

Turtles seem to be the stars of ancient reptiles, don’t you think? It may probably be because of their hardy physical bodies that contributed to their resilience.

And one of those ancient reptiles who’ve survived the years are the Giant Tortoises. However, they’re now endangered due to loss of habitat which is why we must take the necessary steps needed to safeguard the environment for the well-being of ancient reptiles like these. Giant Tortoises are also the world’s oldest reptiles because of their lifespans that reach up to 150 years.

Ancient Reptiles #9: Cantor's Giant Softshell Turtle


Source by: Dementia – Flickr: Pelochelys cantorii

Scientific Name: Pelochelys cantorii

Years in Existence: 140 million years

This softshell turtle from Southeast Asian countries like Borneo and the Philippines is a stark contrast in physical looks to its hard-shelled relatives. Cantor’s Giant Softshell Turtle has a broad head, small eyes, and a snout-shaped nose. Its shell is smooth and dark green, unlike other turtles who have ridges on its shell.

Despite its sluggish look, this ancient reptile is fast. So much so that it can ambush and overpower its prey.

Ancient Reptiles #10: The Gharial (Long-Snouted Crocodile)


Source by: Charles J. Sharp – Own work

Scientific Name: Gavialis gangeticus (Aldabra), Chelonoidis nigra (Galapagos)

Years in Existence: 4,000 years

The long-snouted crocodile, called the Gharial, is an ancient reptile that came from ancient crocodiles over 40 million years ago. It’s an amazing crocodile because of its unique snout it uses to prey on fish that sets it apart from the others. Populations of Gharials can be found in India such as the Corbett National Park, the Hastinapur Wildlife Sanctuary, and the Gandaki River.

Ancient Reptiles #11: Chinese Alligator


Source by: Stolz, Gary M

Scientific Name: Alligator sinensis

Years in Existence: 40 million years

Here’s another one from the first reptiles, the Chinese alligator. The Chinese alligator is a relative of the American alligator whose habitat is in China.

It’s a special gator that grows only up to 2 meters long and lives in burrows in wetlands. This unique ancient reptile is a creature you shouldn’t underestimate despite its size because it can eat animals like birds, rodents, and fish that can be bigger than itself when the opportunity strikes.

Ancient Reptiles #12: The Tuatara (Lizard-like Ancient Reptile)


Source by: Sid Mosdell from New Zealand – Tuatara

Scientific Name: Sphenodon punctatus

Years in Existence: 250 million years

If there was ever anything such as a living fossil, the Tuatara is a good representation. It’s an ancient reptile that’s endemic to New Zealand and is a cultural icon to the Maori tribe living in the country.

These ancient reptiles come from the first reptiles called the Sphenodontia whose lineage is over 250 million years old which is why the Tuatara is often called the living fossil. It’s a reptile that’s carnivorous, territorial, and lizard-like in appearance.

They make their homes in burrows and are nocturnal creatures too. But sometimes they come out in the day for a short sunbath (we’re not kidding). Odd creatures but fascinating, nonetheless.

Ancient Reptiles #13: Komodo Dragon


Source by: Danadi Sutjianto – Own work

Scientific Name: Varanus komodoensis

Years in Existence: 4 million years

Did you know dragons are ancient reptiles too? You read that right and you’ll find them in the form of Komodo Dragons. Fossils of Komodo dragons were found in Australia and were dated way back to the Pliocene period (3 MYA).

Though their fossils were found in Australia, these ancient reptiles eventually found their way to Indonesia which they now call home. As to how this happened remains a mystery.

The Komodo dragon is a venomous hunter who conquers its prey using its physical strength and venomous bite. They’re even known to cause fatal attacks on humans because of their predatory nature. Caution is advised when around these ancient reptiles.

Ancient Reptiles #14: Chapman's Pygmy Chameleon


Source by: Colin Tilbury on Mongabay

Scientific Name: Rhampholeon chapmanorum

Years in Existence: 40 million years

You might have noticed that several ancient reptiles like this one, Chapman’s Pygmy Chameleon, are considered rare and endangered. Populations are decreasing in number because of threats like climate change and the destruction of their natural habitats.

Some even become pets because ancient reptiles breeder make catching and breeding them their line of business. There’s no problem trying to make a profit or wanting to have a pet reptile but we must be mindful of these animal’s welfare too. Let’s think about whether their existence will survive if we continue exploiting their natural habitat and continue taking them out of the wild

On a lighter note, chameleons like Chapman’s pygmy chameleon are fascinating reptiles. They’re small lizards found in East Africa around the area of Malawi Hill whose uniqueness comes from its ability to mimic the color of leaves. That ability protects and camouflages them from foes. They’re also tiny, growing only as long as 6.2cm which adds to the wonder of beholding them.

These reasons are probably why reptile traders like them. They’re also reasons for us to uphold these ancient reptiles’ welfare and protect them from extinction.

Ancient Reptiles #15: Union Island Gecko


Source by: iWitness News

Scientific Name: Gonatodes daudini

Years in Existence: 30 million years

This ancient reptile’s got a bejeweled look because of its red black and white jewel-like pattern on its body. This surely caught the eyes of ancient reptiles breeder as these animals are now endangered because of their poaching.

These Union Island geckos must have inherited good genes from their ancient family line, the Sphaerodactylidae. Those first reptiles’ good looks have been running in the family for more than 30 million years which we see today in the Union Island Gecko’s features.

Bridging Ancient Reptiles & Modern-Day Humans


Source by: Narciso Arellano on Unsplash

Now we see how intricate the evolution of reptiles is and consequently, every living creature. Evolution is complex and also rich with meaning. And this is because it not only speaks about Earth’s prehistoric life, but it speaks about our own too as breakthroughs in research happen.

So we encourage you to look forward to the discoveries about ancient reptiles science will make this year. Because through those, we gain discovery of ourselves too. You’ll see life on earth, animals, and yourself under a new light.

And we have a hunch, you won’t look at those animatronic dinosaurs in theme parks the same way again. You’ll see them with a deeper understanding of their own unique story which in turn, will give you a different way of appreciating and enjoying them. There are also some other particular dinosaurs in the blog Top 8 Swimming & Water Dinosaurs, which you can click to read if you are interested in.

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