Most of us think of dinosaurs when we picture prehistoric life.
However, they weren’t the only creatures stomping, swimming, or slithering around back then. Some animals that existed during the time of the dinosaurs, or even before them, never actually left. They stuck around, evolved just enough to survive, and now we walk the same planet as living fossils. Here are 10 modern-day animals with seriously ancient roots.
1. Horseshoe crabs
These odd-looking creatures look like something out of a sci-fi film, but they’ve been crawling along the ocean floor for over 450 million years — long before dinosaurs ever showed up. That’s older than trees, if you can believe it. They haven’t changed much since then either, which is why they’re often called “living fossils.” Their copper-based blue blood is even used in modern medicine to test vaccines for safety. So prehistoric, but still relevant.
2. Coelacanths
Thought to be extinct for 66 million years, coelacanths shocked the scientific world when one was found alive off the coast of South Africa in 1938. These deep-sea fish are like ghosts from the past—slow, mysterious, and ancient. With limb-like fins and a massive size, they give us a glimpse into what fish were doing as they started inching toward life on land. They’ve changed so little that studying them feels like flipping through the pages of Earth’s oldest biology book.
3. Nautiluses
Looking like a floating snail inside a spiralled shell, the nautilus has been gliding through the oceans for more than 500 million years. It predates dinosaurs, fish with jaws, and possibly even your last houseplant. Despite their age, they’re still doing just fine, slowly rising and falling in the ocean by regulating gases in their shell. They’re one of the most graceful throwbacks we’ve got.
4. Crocodiles
Crocodiles are basically the original apex predators. They’ve been around for about 200 million years and once lived alongside (and probably ate) dinosaurs. Modern crocs haven’t changed all that much since those days. They’re perfectly adapted to life in water and on land, with powerful jaws, stealthy movement, and the kind of patience that lets them wait hours for prey to make one wrong move. Prehistoric and still terrifying.
5. Sharks
Sharks have been swimming Earth’s oceans for over 400 million years. That’s twice as long as dinosaurs lasted, and they’re still going strong. Some species, like the frilled shark, haven’t changed much at all in that time. These ancient fish have survived mass extinctions, drastic climate shifts, and millions of years of evolution. Their secret? Adaptability and attitude. Sharks don’t mess around.
6. Tuataras
At first glance, tuataras look like lizards, but they’re part of a completely different, ancient lineage. These reptiles from New Zealand go back about 250 million years, and they’ve stayed remarkably consistent ever since. They even have a “third eye” on the top of their heads, which is visible in juveniles. It doesn’t give them superpowers, but it does help them regulate their day-night rhythms. Weird, wonderful, and very, very old.
7. Jellyfish
With their soft, squishy bodies, jellyfish might not scream “prehistoric survivor,” but they’ve been pulsing through oceans for over 500 million years. Some fossil evidence even hints they’re older than that. They’ve managed to survive this long with no brains, no bones, and no blood. Just simple, efficient design that hasn’t needed much tweaking in half a billion years. Not bad for a blob.
8. Sturgeon
Sturgeon are often overlooked, but they’ve been around since the time of the dinosaurs, which is roughly 200 million years. They can live over 100 years and grow to the size of a small car, depending on the species. They haven’t changed much in appearance since ancient times, which makes them one of the more impressive freshwater holdovers from the past. If rivers had ghosts, sturgeon would be it.
9. Komodo dragons
These giant lizards have a prehistoric vibe, and for good reason. While they’re “only” about four million years old, they belong to a lineage that stretches much further back. They’re the largest living lizards and very much look the part. Komodo dragons can take down large prey with a toxic bite and have an intimidating presence that wouldn’t feel out of place in a dinosaur documentary. Modern predators, ancient legacy.
10. Lampreys
Lampreys are eel-like, jawless fish with circular, suction-cup mouths full of teeth, and they’ve been around for roughly 360 million years. That design might seem unsettling, but it clearly works. They haven’t changed much since the Devonian period, and while some species are parasitic, others live quietly in freshwater streams. Either way, they’re living proof that weird sometimes wins when it comes to survival.