18 Extinct Turtles That Once Ruled the Earth (And the Ocean)
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Turtles today are cute, chill, and occasionally grumpy if you interrupt their basking.
But millions of years ago?
They were giants, gladiators, world travelers, and straight-up weirdos.
Some had horns. Some had flippers longer than your arms. One was discovered in pieces—over 160 years apart.
I went deep into the fossil record (so you don’t have to) and dug up 18 of the most fascinating extinct turtles to ever waddle, swim, or stomp across this planet.
Each one had its own story, its own style, and sadly, its own extinction.
Get ready to meet turtles that could crush a crocodile, surf ancient seas, or eat plants like it was their full-time job.
Let’s bring them back to life — one shell at a time.
1. Archelon ischyros
Let’s kick things off with the turtle that makes all other turtles look like action figures. Archelon wasn’t just big — it was absurdly big. If sea turtles had a king, this dude wore the crown, the cape, and probably scared off anything that blinked.
Time Period
This big guy swam around during the Late Cretaceous, about 80 to 74 million years ago. That’s dino time — but Archelon dipped out before the asteroid showed up.
Location
Fossils popped up in South Dakota, USA. Back then, it was part of a shallow inland sea. Not exactly beach resort material, but good enough for a giant turtle.
Size and Appearance
Imagine a turtle the size of a small car. Up to 13 feet long and weighing over 2 tons.
Its shell wasn’t hard like your backyard tortoise — it was leathery and flexible. Think “softshell tank.” It also had long flippers, a small tail, and a sharp beak that screamed “don’t mess with me.”
Behavior and Diet
Archelon probably cruised through the sea like a slow-motion submarine, snacking on jellyfish, squid, and other soft-bodied sea snacks. It didn’t need teeth — that beak did all the work.
Causes of Extinction
Blame natural causes. Climate shifts, changing oceans, and the usual chaos of prehistoric life probably took it out. It didn’t stick around long enough to meet the asteroid.
Discovery History
Dr. George Reber Wieland found the first fossil in 1895. A giant sea turtle buried in South Dakota? Must’ve been a wild day at the office.
Interesting Facts
It’s the largest sea turtle ever known. Also, its shell was more of a skeletal frame than a solid dome — kind of like a turtle exoskeleton hammock.
Modern Relatives
The leatherback sea turtle is Archelon’s closest modern cousin. Same soft shell, same oceanic road trip vibes.
Fossil Locations Today
Want to meet Archelon? Head to the Smithsonian or Yale’s Peabody Museum and stare in awe.
2. Meiolania platyceps
You ever seen a turtle with horns? No? That’s because they went extinct. Meiolania looked like it got its shell from a tank, its head from a triceratops, and its tail from a mace. It didn’t live in the water much, but it sure made a splash in turtle history.
Time Period
Lived from the Late Pleistocene to the early Holocene — somewhere between 50,000 to 2,000 years ago. Which means it may have been walking around when humans were already throwing spears and starting fires.
Location
Found in Australia and Lord Howe Island. Its turf? Forests and coastal land. Not a water baby — this one liked dry ground.
Size and Appearance
These dudes were tanky. Around 8 to 9 feet long, with a tail club that looked like it belonged to a medieval knight. Oh, and it had horns on its head. Yes, horns.
Behavior and Diet
Moved slowly and munched on plants, fruits, and low shrubs. Think giant herbivore with a punk rock headpiece.
Causes of Extinction
Humans probably had something to do with it. Hunting and clearing out its home turf didn’t help its survival chances.
Discovery History
Fossils turned up in Lord Howe Island caves in the 1800s. Imagine hiking and stumbling upon a turtle skull with horns. Wild.
Interesting Facts
Couldn’t pull its head into its shell because of the horns.
And that tail club? Straight out of a dinosaur movie.
Modern Relatives
It’s part of a now-dead turtle family called Meiolaniidae. Closest living cousins would be land tortoises, but this one was a total oddball.
Fossil Locations Today
You can check out the fossils at the Australian Museum in Sydney or the Lord Howe Island Museum if you’re ever in the area.
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3. Carbonemys cofrinii
Meet Carbonemys — a turtle so tough, it shared its neighborhood with a 40-foot snake and didn’t flinch. This chunky beast ruled the swamps after the dinosaurs were gone, chomping anything that got too close to its snapping jaws.
Time Period
After the dinosaurs bowed out, this beast showed up. Around 60 million years ago, during the Paleocene.
Location
Discovered in a Colombian coal mine. It used to live in freshwater rivers and murky swamps.
Size and Appearance
Roughly 5.5 feet long. With a thick shell and jaws that looked like they could crush a pineapple — or a small crocodile.
Behavior and Diet
Probably ate anything it could bite — fish, plants, even unlucky animals. It wasn’t picky. It may have been the swamp boss, right under Titanoboa (the giant snake).
Causes of Extinction
Slow and steady didn’t win this race. Climate shifts and changing wetlands likely did it in.
Discovery History
Found in 2005 and officially described in 2012. The fossil team had a big “holy crap” moment.
Interesting Facts
It lived side by side with the Titanoboa, a snake so huge it makes anacondas look like garden hoses.
Modern Relatives
Part of the side-necked turtle gang. If you’ve seen South American river turtles today — that’s the family line.
Fossil Locations Today
Stored in Colombia’s Geological Institute and also at the Smithsonian Tropical Research Institute.
4. Stupendemys geographicus
This one’s for the people who think turtles are slow, small, and boring. Stupendemys was the SUV of freshwater turtles. Ten feet long, built like a kayak, and possibly using shell horns to settle scores — it made the Amazon its stomping ground.
Time Period
This mega-turtle lived during the Miocene, around 6 to 10 million years ago.
Location
South America’s tropical wetlands — Colombia, Venezuela, Brazil, and Peru. Basically, the ancient Amazon jungle’s turtle king.
Size and Appearance
About 10 feet long and over a ton in weight. Some males had horn-like bumps on their shells — maybe for wrestling matches or showing off.
Behavior and Diet
Strictly plant-based. This giant floated through rivers chomping on aquatic greens.
Causes of Extinction
The wetlands dried up, new turtle competition moved in, and Stupendemys checked out.
Discovery History
First found in the 1970s, but a fresh batch of fossils — including skulls — dropped in 2020 and gave us the full picture.
Interesting Facts
It’s one of the largest freshwater turtles ever. Also had to share rivers with massive crocs. Talk about awkward roommates.
Modern Relatives
It’s related to modern Amazon river turtles in the Podocnemididae family.
Fossil Locations Today
You’ll find specimens in the University of Zurich and Venezuela’s Natural History Museum.
5. Niolamia argentina
Horned, spiky, and armored like it was expecting a medieval joust, Niolamia was South America’s prehistoric bouncer. It didn’t hide in its shell — it showed up to the party looking like it invented the shell.
Time Period
Roughly 50 million years ago during the Eocene Epoch.
Location
Patagonia, Argentina. Dry land with possible water sources nearby — perfect for a big horned crawler.
Size and Appearance
Around 6.5 feet long, horned skull, and a tail that could pass as medieval weaponry. Thick shell armor sealed the deal.
Behavior and Diet
Mostly a plant eater, and built to survive predators with its armored body and spikehead.
Causes of Extinction
No humans around yet. Nature just got a bit too wild and unpredictable.
Discovery History
Discovered in 1899 by Florentino Ameghino, an Argentine paleontology legend.
Interesting Facts
Was one of the first horned turtles found in South America. Paved the way for learning about the Meiolaniidae family.
Modern Relatives
It has no living relatives. Its whole turtle crew went extinct.
Fossil Locations Today
If you’re ever in Buenos Aires, check it out at the Museo Argentino de Ciencias Naturales.
6. Psephophorus polygonus
Ever wonder what sea turtles looked like before they got their modern upgrades? Psephophorus was like the prototype leatherback — early, weird, and oddly stylish. It didn’t have a hard shell, but it had the moves to rule the open ocean.
Time Period
It swam through the Miocene seas, about 10 to 15 million years ago.
Location
Fossils popped up in Europe (Austria, Germany) and even New Zealand. It lived in open marine waters, riding waves long before surfers showed up.
Size and Appearance
About 6 to 9 feet long, with a leathery, flexible shell covered in bony plates that looked like a turtle mosaic. Sleek and built to cruise.
Behavior and Diet
Jellyfish fan, soft prey specialist, and a long-distance ocean wanderer. Basically the OG leatherback lifestyle.
Causes of Extinction
Changes in the ocean may have knocked it out. Newer, better-adapted turtles probably stole its lunch money.
Discovery History
First described in the 1800s from marine limestone in Europe. Yep — turtles have been fossil famous for a while.
Interesting Facts
Its shell structure is so similar to modern leatherbacks, you’d think they were roommates.
Modern Relatives
Direct ancestor of the leatherback sea turtle (Dermochelys coriacea). Grandma, is that you?
Fossil Locations Today
Natural History Museum in Vienna, and collections in Germany and New Zealand.
7. Leviathanochelys aenigmatica
With a name that sounds like a sea monster boss in a video game, Leviathanochelys was Europe’s largest marine turtle. And honestly, it wore that title like a champ — mysterious, massive, and kind of terrifying.
Time Period
Lived during the Late Cretaceous, around 83.6 to 72.1 million years ago.
Location
Its fossils came from northeastern Spain, a region once covered in ancient seas.
Size and Appearance
Estimated at 12.3 feet long. What really stood out? A pelvis with a bizarre protrusion — like nothing we’ve seen before.
Behavior and Diet
Probably floated around eating soft-bodied marine animals. Gentle giant energy with big swimmer vibes.
Causes of Extinction
Like many Cretaceous sea creatures, it got wiped out by big environmental changes — probably long before the asteroid showed up.
Discovery History
Discovered between 2016 and 2021. Scientists officially described it in 2022, and the paleontology world freaked out (in a good way).
Interesting Facts
Biggest marine turtle found in Europe. And that weird pelvis? Paleontologists still aren’t sure what it was for.
Modern Relatives
Linked to the leatherback family. Another ancestor with no time for a hard shell.
Fossil Locations Today
Currently housed in Spanish museums, though details are still hush-hush.
8. Cratochelone berneyi
Cratochelone was Australia’s gentle sea giant before it was cool. Massive, mysterious, and mostly known from fragments — but the size alone made it a local legend.
Time Period
Cruised the seas during the Early Cretaceous, between 100 and 113 million years ago.
Location
Found in Queensland, Australia. This place used to be an ancient ocean buffet.
Size and Appearance
Estimated length? Up to 13 feet. That’s a whole living room rug. Fossils suggest it had powerful limbs and a big sea turtle frame.
Behavior and Diet
Likely munched on soft sea creatures and drifted through marine currents. Classic sea turtle stuff, but with more drama.
Causes of Extinction
No humans to blame here. Just natural marine shakeups doing what they do best.
Discovery History
Discovered over 100 years ago and described in 1915 by Heber Longman. That’s some true paleontology vintage.
Interesting Facts
One of the biggest sea turtles of its time — and we barely know anything about it. Classic mysterious fossil energy.
Modern Relatives
Part of the Protostegidae family. Basically, the leatherback turtle’s ancient gang.
Fossil Locations Today
Queensland Museum has the goods if you want to meet this Aussie legend in person.
9. Santanachelys gaffneyi
Small but mighty, Santanachelys didn’t break records with its size — but it’s one of the earliest sea turtles we know. Picture it as the ancient cousin that got everything started.
Time Period
Early Cretaceous — around 112 million years ago.
Location
Brazil’s Santana Formation. Yep, named after that fossil-rich rock concert of a location.
Size and Appearance
Tiny, only about 8 inches long. Had digits on its flippers and salt glands near its eyes. Basically, a baby sea turtle with advanced features.
Behavior and Diet
Fed on small marine life and was fully adapted to ocean living. Cute but functional.
Causes of Extinction
Not a dramatic ending — just slowly phased out by evolution. Quiet turtle exit.
Discovery History
Discovered in the Santana Formation and described in 1998 by Hirayama.
Interesting Facts
It’s the sea turtle blueprint. Without Santanachelys, your beach selfies with sea turtles might not exist.
Modern Relatives
Early member of the sea turtle superfamily. A literal ancestor of today’s sea turtles.
Fossil Locations Today
Held in both Brazilian and Japanese museum collections.
10. Amabilis uchoensis
Tiny, adorable, and extinct — Amabilis uchoensis is the kind of turtle that makes paleontologists go “awww” before hitting them with a 100-million-year-old reality check.
Time Period
Late Cretaceous, roughly 86.3 to 83.6 million years ago.
Location
Brazil, in freshwater areas of what’s now São Paulo state.
Size and Appearance
Super small. Its skull was less than an inch long. One of the cutest fossils ever found.
Behavior and Diet
Probably fed on tiny aquatic creatures and just vibed in freshwater streams.
Causes of Extinction
Mother Nature flipped the climate switch again, and the little guy didn’t make the cut.
Discovery History
Found in the São José do Rio Preto Formation. Described in 2020 by Hermanson and crew.
Interesting Facts
Its name, Amabilis, means “lovable.” Paleontologists really do have hearts.
Modern Relatives
A side-necked turtle. Related to today’s South American freshwater turtles.
Fossil Locations Today
You’ll find this mini fossil at the Uchoa Museum of Paleontology in Brazil.
11. Aurorachelys
Turtles in the Arctic? Yep. Aurorachelys wasn’t just cold-blooded — it was cold-living. This ancient shelled wanderer proved turtles didn’t mind a little chilly travel now and then.
Time Period
Lived during the Late Cretaceous, around 90 million years ago.
Location
Found way up in the Canadian High Arctic, on Axel Heiberg Island. Back then, the area was way warmer and lush.
Size and Appearance
Exact size isn’t nailed down, but the fossils suggest a turtle built for freshwater life — not a sea cruiser, but a pond stomper.
Behavior and Diet
Likely munched on small aquatic animals and plants. Adapted to freshwater and maybe took long naps in sunlit Arctic pools.
Causes of Extinction
When the planet’s thermostat dropped, so did its chances. Climate change did its thing.
Discovery History
Discovered in 2009 by a team led by John Tarduno. Turns out, the Arctic had more than just ice and fossils of pine trees.
Interesting Facts
Its existence supports the idea that turtles once migrated across the Arctic during warm periods. Global travelers, even back then.
Modern Relatives
Ties to today’s freshwater turtles — the slow-and-steady crew.
Fossil Locations Today
Stored at the Royal Tyrrell Museum of Palaeontology in Alberta, Canada.
12. Chelonoidis alburyorum
This isn’t some distant ancient turtle — Chelonoidis alburyorum was still roaming around the Bahamas just 600 years ago. Yes, your ancestors might’ve walked right past it. And probably ate it, too.
Time Period
Late Pleistocene to early Holocene. It went extinct around 1400 CE.
Location
Lucayan Archipelago — Bahamas, Turks and Caicos. A true island tortoise.
Size and Appearance
About 19 inches long, with a strong domed shell. Not huge, but a chunky land-dweller.
Behavior and Diet
Herbivore vibes all the way — grass, fruit, leaves, the usual leafy buffet.
Causes of Extinction
Sadly, early humans showed up and started hunting it. Combine that with habitat damage and boom — no more island tortoise.
Discovery History
Named in 2017 after Nancy Albury, who led the cave fossil discoveries in the Bahamas.
Interesting Facts
It’s one of the most recently extinct turtles. We just missed meeting it by a few centuries.
Modern Relatives
Part of the Chelonoidis genus, same as the famous Galápagos tortoises.
Fossil Locations Today
Check the National Museum of The Bahamas if you want to see what we lost.
13. Proterochersis robusta
Let’s take a deep time dive. This one goes way back. Proterochersis wasn’t just an ancient turtle — it was among the first to ever sport a full shell. Respect your elders.
Time Period
Late Triassic. About 210 million years ago. That’s older than most dinosaurs.
Location
Found in Germany, in what’s now the Trossingen Formation.
Size and Appearance
About 2 feet long. It had a thick, rounded shell — but none of the fancy modern scutes.
Behavior and Diet
Probably ate plants and soft creatures. Moved slow, looked ancient, and didn’t care what others thought.
Causes of Extinction
The usual prehistoric drama — slow environmental changes that it couldn’t outlast.
Discovery History
Unearthed in the 1800s. It’s been blowing paleontologists’ minds ever since.
Interesting Facts
One of the oldest fully-shelled turtles ever found. A true trailblazer in the turtle timeline.
Modern Relatives
Possibly a distant side-necked turtle ancestor. But it’s a bit of a mystery.
Fossil Locations Today
Stuttgart State Museum of Natural History, Germany. Home to grandpa turtle.
14. Palaeomedusa testa
Take a turtle, give it paddle limbs, and throw it into Jurassic waters — you’ve got Palaeomedusa testa. This small marine wanderer kept things simple, sleek, and pretty darn old-school.
Time Period
Late Jurassic, about 150 million years ago.
Location
Southern Germany, in the famous Solnhofen limestone. Same place they found Archaeopteryx. Fossil hotspot alert.
Size and Appearance
About 1.6 feet long. Flat, oval shell. Paddle-like limbs for swimming, and a face that probably said “I eat fish.”
Behavior and Diet
Likely carnivorous — snacked on tiny sea animals. Swam like a champ, but maybe preferred shallow areas.
Causes of Extinction
Shift in marine ecosystems knocked it out. Nature hit refresh.
Discovery History
Found in the 1800s and became part of the earliest fossil turtle research.
Interesting Facts
One of the best-preserved Jurassic turtles. It fossilized in the same rocks that made Archaeopteryx famous.
Modern Relatives
Maybe tied to side-necked turtles. Scientists are still debating it.
Fossil Locations Today
Natural History Museum, Berlin. Historic fossil in a historic museum.
15. Mongolochelys efremovi
Mongolochelys sounds like a spell from a fantasy novel — and honestly, it lived in a landscape just as harsh. This turtle braved the Gobi Desert back in the dinosaur days.
Time Period
Late Cretaceous, around 70 million years ago.
Location
Mongolia’s Gobi Desert, back when it had more life and fewer sandstorms.
Size and Appearance
About 6 feet long, with a high, dome-shaped shell and legs made for walking, not swimming.
Behavior and Diet
Likely grazed on dry, tough plants. Built for life on land, not for lazy days in ponds.
Causes of Extinction
End-Cretaceous climate changes probably pushed it off the map.
Discovery History
Named in the 1970s after Russian paleontologist Ivan Efremov. Fossils came from deep desert expeditions.
Interesting Facts
It’s one of the largest land turtles found in Asia. And its fossils are rare — no turtle bones just lying around out there.
Modern Relatives
It has no direct modern match, but shares roots with early land turtle lineages.
Fossil Locations Today
You’ll find it at the Paleontological Center in Mongolia — if you can handle the journey.
16. Chrysemys idahoensis
Say hello to a turtle that looked suspiciously like the one basking on a log at your local pond… except this one’s been gone for millions of years. Chrysemys idahoensis was like the prehistoric prototype of today’s painted turtle.
Time Period
Hung around during the Miocene Epoch, about 6 to 12 million years ago.
Location
Western U.S. — Idaho and Oregon. Back then, it was freshwater paradise with streams, ponds, and no plastic waste in sight.
Size and Appearance
Roughly the size and shape of modern painted turtles. No color left in the fossils, but it probably had some nice racing stripes.
Behavior and Diet
Likely an omnivore. Think bugs, plants, small fish — the usual turtle smorgasbord. Also probably loved sunbathing like its modern relatives.
Causes of Extinction
Climate started cooling toward the end of the Miocene, and this little guy couldn’t keep up.
Discovery History
Fossils found in the mid-1900s around the Snake River region.
Interesting Facts
May have been a direct ancestor to Chrysemys picta, the modern painted turtle. Which means this one’s family still shows up in kids’ nature books today.
Modern Relatives
Painted turtles — its evolutionary grandkids are still doing turtle things all over North America.
Fossil Locations Today
Specimens live at the University of Idaho and other regional fossil collections.
17. Hadrianus majusculus
This guy took the scenic route — fossils have been found across three continents. Hadrianus majusculus didn’t just survive, it thrived during a time when tortoises were making global moves.
Time Period
Eocene Epoch, around 55 million years ago.
Location
Europe, North Africa, North America. Forested environments, warm climates, and no customs checks for tortoises.
Size and Appearance
Medium-sized, about 1.5 to 2 feet long. High domed shell, rounded — your classic tortoise silhouette.
Behavior and Diet
Herbivore with a leaf-eating habit. Slow, steady, and likely sun-loving.
Causes of Extinction
Global cooling near the end of the Eocene did them in. When the temperature dropped, these guys couldn’t adapt.
Discovery History
First fossils found in France, later in places like Wyoming and Morocco. This tortoise got around.
Interesting Facts
Helped scientists understand tortoise migration and the land bridges that made it all possible.
Modern Relatives
Related to Mediterranean tortoises — yep, the ones you see in pet shops today.
Fossil Locations Today
Natural History Museum in Paris and Denver Museum of Nature & Science.
18. Atlantochelys mortoni
Atlantochelys mortoni wins the prize for most dramatic fossil reunion. Two pieces of its limb bone were found 163 years apart. Imagine losing your leg and someone finding it over a century later.
Time Period
Late Cretaceous, around 70 to 75 million years ago.
Location
New Jersey, USA. Back then, it was coastal waters — not pizza and traffic jams.
Size and Appearance
About 10 feet long. Big flippers, smooth shell, sleek swimmer build.
Behavior and Diet
Likely fed on jellyfish and soft-bodied sea life. Cruised the coast like a prehistoric yacht.
Causes of Extinction
Wiped out as part of the marine crash around the time of the asteroid strike. Classic Cretaceous ending.
Discovery History
Part of its limb was found in 1849. Then in 2012, another piece was found — and matched perfectly. That fossil puzzle took generations to finish.
Interesting Facts
That 163-year gap between fossil halves made headlines. Basically the most patient turtle in fossil history.
Modern Relatives
Closest match: leatherback sea turtles. Same soft-shelled ocean drifter DNA.
Fossil Locations Today
You can visit the limb reunion at the Academy of Natural Sciences in Philadelphia.
About Author
Muntaseer Rahman started keeping pet turtles back in 2013. He also owns the largest Turtle & Tortoise Facebook community in Bangladesh. These days he is mostly active on Facebook.
