Around the world, people are celebrating the Chinese New Year and the start to the Year of the Dragon. This got us wondering: Where did the myth of the dragon come from in the first place? Scholars say that belief in dragons probably evolved independently in both Europe and China, and perhaps in the Americas and Australia as well. How could this happen? Many have speculated about which real-life animals inspired the first legends. Here’s our run-down of the likeliest suspects.

Dinosaurs. Ancient people may have discovered dinosaur fossils and understandably misinterpreted them as the remains of dragons. Chang Qu, a Chinese historian from the 4th century B.C., mislabeled such a fossil in what is now Sichuan Province. Take a look at a fossilized stegosaurus, for example, and you might see why: The giant beasts averaged 30 feet in length, were typically 14 feet tall and were covered in armored plates and spikes for defense.

The Nile Crocodile. Native to sub-Saharan Africa, Nile crocodiles may have had a more extensive range in ancient times, perhaps inspiring European dragon legends by swimming across the Mediterranean to Italy or Greece. They are among the largest of all crocodile species, with mature individuals reaching up to 18 feet in length—and unlike most others, they are capable of a movement called the “high walk,” in which the trunk is elevated off the ground. A giant, lumbering croc? Might be easy to mistake for a dragon.

The Goanna. Australia is home to a number of species of monitor lizards, also referred to as Goannas. The large, predatory animals have razor-sharp teeth and claws, and they are important figures in traditional Aboriginal folklore. Recent studies even indicate that Goannas may produce venom that causes bite victims’ wounds to develop infections after an attack. At least in Australia, these creatures may be responsible for the dragon myth.

Whales. Others argue that the discovery of megafauna such as whales prompted stories of dragons. Ancient humans encountering whale bones would have no way of knowing that the animals were sea-based, and the idea of such gargantuan creatures might well have led people to assume that whales were predatory. Because live whales spend up to 90 percent of their time underwater, they were poorly understood for most of human history.

The Human Brain. The most fascinating explanation involves an unexpected animal: the human. In his book An Instinct for Dragons, anthropologist David E. Jones argues that belief in dragons is so widespread among ancient cultures because evolution embedded an innate fear of predators in the human mind. Just as monkeys have been shown to exhibit a fear of snakes and large cats, Jones hypothesizes that the trait of fearing large predators—such as pythons, birds of prey and elephants—has been selected for in hominids. In more recent times, he argues, these universal fears have been frequently combined in folklore and created the myth of the dragon.