Ancient Giants: The Evolution Of Turtles Through The Ages

Written by: Neira Eclarinal

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Introduction: Why Are We So Fascinated by Turtles?

Have you ever wondered why turtles captivate our imaginations? From Aesop’s fables to the Teenage Mutant Ninja Turtles, these shelled creatures spark curiosity. But did you know turtles are much more than just cool reptiles? Their story began millions of years ago, surviving through epochs and monumental changes on Earth. And it’s not just any story. It’s a tale of giants, survival, and incredible adaptations.


In this blog post, we'll dive deep into the ancient world of turtles. You'll learn why their evolutionary journey is nothing short of a blockbuster movie. Stay tuned, because by the end of this article, you’ll know more about these incredible creatures and why they’ve stood the test of time.

Turtle Anatomy and Its Evolution: What Makes a Turtle a Turtle?

Photograph by Joel Sartore Dynamic wildlife photography

The Shell: A Unique Defense Mechanism

Turtles have this unique body plan that sets them apart. The shell! Imagine carrying your house on your back. That’s literally what turtles do. The shell is a fantastic piece of biological engineering made up of over 60 bones, including the spine and ribs! It’s not just a shield; it’s a part of their skeleton.


The shell itself consists of two parts – the upper carapace and the lower plastron. Both of these components even include parts of the shoulder girdle. Fascinating, right?


Dried and crushed skeleton of a turtle fused in a rock

Evolution of the Shell: From Broad Ribs to Complete Armor

In the beginning, turtles didn’t have the full hard shell we see today. Imagine some proto-turtle, around 260 million years ago, named Eunotosaurus, which had broadened ribs but no complete shell. Fast forward to Odontochelys around 220 million years ago, and we see a proto-turtle with a partially developed shell (plastron) but not the carapace. Then, about 210 million years ago, Pregonachelys emerged as the oldest fully shelled turtle. These ancestors show how the mighty shell evolved so intricately over time.


Cultural Significance: Why Humans Love Turtles

The earth

Myths and Legends: The Earth on a Turtle’s Back

Turtles aren’t just cool animals; they’re cultural icons. From ancient myths where the Earth rests on a giant turtle (think Hindu and Chinese mythology) to being major characters in quests and stories like George RR Martin's "Game of Thrones" inspiration, these creatures have always fascinated us.


Modern Media: Ninja Turtles and More

Fast forward to today, and turtles have entered modern pop culture in a big way. Ever heard of the Teenage Mutant Ninja Turtles? Or the wise, ancient turtle from "Kung Fu Panda"? Our fascination with these reptilian knights in shining armor continues. Who doesn’t love a good turtle story?


Biodiversity and Current Distribution: Where Are They Now?

intimate portrait photography of sea turtle

The Global Spread of Turtles

Today, there are over 356 living species of turtles. They live everywhere—oceans, rivers, lakes, and swamps. The largest biodiversity hotspot for these ancient giants? The Eastern United States. Isn’t that amazing?


Adaptations to Various Environments

Turtles are like nature's version of adaptable superheroes. Sea turtles slice through ocean waves with powerful flippers. Freshwater turtles swim gracefully in rivers and lakes, while land turtles lumber slowly but surely in forests and deserts. Their adaptations show why they’ve thrived for millions of years.


Fun Facts: Did You Know?

Longevity: The 175-Year-Old Tortoise

Ever met someone who’s 175 years old? Harriet, a giant tortoise who was one of Charles Darwin's pets, lived that long! Some turtle species can easily outlive humans, with lifespans reaching over a century.


Harriet, a giant tortoise who was one of Charles Darwin

Surviving Without Oxygen: Nature’s Miracle

Imagine holding your breath for 24 hours. Impossible, right? Not for turtles! Some species can live up to 24 hours without oxygen and survive submerged in cold water for up to six months. They achieve this with blood shunting and metabolic slowing—literally a slow-motion superpower.


Cloaca Respiration: Butt-Breathing Turtles

Here's a real kicker: some turtles can breathe through their butts! It’s called cloaca respiration. The Fitzroy River turtle, for example, can stay underwater for extended periods, breathing through its cloaca. Talk about an evolutionary twist!


Fossil Record and Evolutionary History: Where Did They Come From?

Early Fossils: A Snapshot of Prehistoric Giants

Fossils give us a window into the past. The oldest sea turtle fossil, dating back 120 million years, was found in Colombia. Another jaw-dropping discovery was the Odontochelys semitestacea, a 220 million-year-old fossil found in China.


Turtles Through Mass Extinctions: Natural Survivors

Did you know turtles have lived through three of the five major mass extinctions, including the colossal Cretaceous-Paleogene extinction that wiped out the dinosaurs? Their secret? Resilient physiology and the ability to hunker down during harsh conditions. When the going gets tough, turtles get going!


Notable Extinct and Living Species: Who Were the Giants?

Basemys: The Titan of the Cretaceous-Paleogene

One illustrious species, Basemys, unfortunately, met its doom during the asteroid impact 66 million years ago. But it left an indelible mark on the evolutionary story of turtles.


Yangtze Giant Softshell Turtle: Modern-Day Goliath

Even today, the Yangtze Giant Softshell Turtle is a living testament to the grandeur of ancient turtles. This modern giant can weigh up to 250 kg and is the superstar of its species.


Yangtze Softshell Turtle

Research Insights and Future Questions: What’s Next?

Ongoing Debates: Exoskeletal or Endoskeletal?

Scientists are still trying to decipher whether the turtle shell is an exoskeleton or an endoskeleton, or perhaps a mix of both. It’s a subject of much debate, feeding our insatiable curiosity about these creatures.


Unanswered Questions: What Will We Discover?

The story of turtle evolution is far from complete. Each new fossil discovery brings us a bit closer to understanding how these ancient giants evolved and adapted. What will we find next?


Conclusion: Why Turtles Are the Ultimate Survivors

To sum it all up, turtles have been through it all—meteor impacts, climate shifts, and more. Yet, their resilient nature adapted and evolved to keep them going. These ancient giants offer us a living glimpse into the past, fascinating us with their adaptability and long history.


Call to Action: Get Involved in Turtle Conservation

Want to be a part of this amazing story? Join turtle conservation programs. Spread awareness about protecting these ancient giants. Every small effort counts. Let’s make sure these incredible creatures can continue their journey through the ages for many more millennia.


Ready to dive deeper into the world of turtles? Check out these additional resources and references:


Additional Resources and References


- [Denver Museum of Nature & Science – Turtle Evolution Exhibit]

https://www.dmns.org/

- [National Geographic – Turtle Anatomy Insights]

https://www.nationalgeographic.com

- [Journal of Systematic Paleontology – New Turtle Fossils]

https://www.tandfonline.com/loi/tsyp20


Your journey through the history of turtles doesn’t end here. Keep exploring, stay curious, and most importantly, help protect these living relics!


There's still so much more to learn about these ancient giants. Engage with the turtle-loving community today and be part of the adventure that spans millions of years!


References:


- “Ancient Turtles.” National Geographic. [National Geographic: Ancient Turtles]

https://www.nationalgeographic.com/animals/reptiles/facts/ancient-turtles

- Nicioli, Taylor. “Scientists Discover a Giant Fossilized Marine Turtle in Spain.” CNN. [CNN: Giant Marine Turtle]

https://www.cnn.com/2023/04/14/world/giant-turtle-fossil-discovery-scn/index.html

- “Fossil Record Reveals Ancient Turtles.” Smithsonian Magazine. [Smithsonian: Ancient Turtles]

https://www.smithsonianmag.com/science-nature/ancient-turtle-fossils-reveal-the-origin-of-the-turtle-shell-13476547/