George Washington didn’t know that dinosaurs existed.

Washington with generals

Did George Washington know about dinosaurs? Most likely, no. Today, the existence of dinosaurs may seem like an immutable fact, but our knowledge of these ancient creatures is a relatively modern development. In fact, the very concept of dinosaurs is so recent that many of the founders of the United States lived most if not all of their lives without knowing that dinos existed. English naturalist Robert Plot described the very first fossilized evidence of dinosaurs, what we now know to be the femur of a megalosaurus, in 1677. But with no concept of dinosaurs in the mid-17th century, Plot theorized that the bone must have belonged to some ancient forgotten race of giant humans.

It’s likely that George Washington died in 1799 believing that such giant humans existed in the distant past. It wasn’t until the 1820s that geologists began to reexamine this theory and proposed that the mysterious bones belonged to an ancient reptile rather than a mammal. Even then, it took until 1842 for English paleontologist Richard Owen to offer up the word “dinosaur,” based on the Greek words for “terrible lizard,” to describe the ancient beasts (not entirely accurate, but close enough). This etymological creation arrived a full decade after Charles Carroll, the longest-surviving signer of the Declaration of Independence, died at the age of 95. The story of the dinosaurs is long and ancient, but our knowledge of them certainly isn’t.

By the Numbers

Did you know?

The T. rex lived closer to humans than to the stegosaurus.

When placed in context of Earth’s 4.54 billion years of existence, the entirety of recorded history is less than a blink of an eye; even Homo sapiens’ most distant ancestors lived only around 5 million to 7 million years ago. The age of dinosaurs, on the other hand, covers 165 million years, so long that the T. rex — the Cretaceous Period apex predator who went extinct around 65 million years ago ― is chronologically closer to humans than to the stegosaurus, the uniquely plated dino that roamed Earth during the late Jurassic, some 155 million to 145 million years ago. (And don’t even get us started on the chronological distance from the T. rex to the Triassic dinos.) Despite the stark differences between their respective moments in history, humans and dinosaurs still occupy the same 541 million-year-long Phanerozoic Eon, itself only a fraction of Earth’s entire geologic story.