Many ancient cultures have stories of fantastic creatures. Did all these people simply imagine dragons, gryphons, or giants?

Today, scientists believe they found fossils and, unable to explain them, gave them exaggerated features of the animals they knew and found places for them in folklore.

For instance, we know Greeks and Romans collected fossil bones. They believed these once belonged to their gods and warrior heroes, who were hailed as giants when the huge bones were found.

These fossils, now known to come from mammoths, were displayed in the Roman capital as late as AD 500.

Long before then, different cultures told stories of gryphons, which were part lion, part eagle and protected Earth’s gold.

Where might this story have come from?

In the Gobi Desert, gold would often erode into streambeds with fossils of Protoceratops. Their skulls somewhat resembled contemporary lions, but with a large eagle-like beak.

Earlier still, dragons appeared in Chinese mythology. While many experts today don’t see a direct fossil connection, there’s an ironic link to the present day:

Many villagers still believe in dragons and grind fossilized “dragon bone” into medicines, as they have for 2,500 years. Paleontologists can often follow the sources of apothecary “dragon bone” to find new fossil beds.

No doubt there are some cases where mythical beasts sprang purely from the imagination, not fossil discoveries. But on a future EarthDate, we’ll look at one famous myth that almost certainly did.