In 1677, the English naturalist Robert Plot published the first known illustration of a dinosaur bone. Only, he didn’t know what it was. At first, he’d wondered if the fossil—discovered in Oxfordshire, England—was an elephant bone from the Roman Empire. After examining a live elephant for comparison, he suggested the bone may have come from a giant.

Historically speaking, this wasn’t an unusual claim. Although researchers didn’t start to understand what dinosaurs were until the 19th century, stories of humans finding the bones of “dragons” or other large creatures go back centuries.

“I think it goes far back in human history that people found dinosaur bones, marveled at them, but probably didn’t have any idea what they were looking at,” says Hans-Dieter Sues, a paleontologist at the Smithsonian National Museum of Natural History.

So when did humans begin to figure out what dinosaurs were?

In 1824, the English palaeontologist William Buckland published a paper on a jawbone fossil from an English village called Stonesfield. Buckland described the creature it belonged to as a large reptile, which is why he used the Greek words for “big lizard” to name it Megalosaurus.

“But other than saying that it was a large predatory animal, he couldn’t really say much about it,” Sues says. This was because “there wasn’t really anything to compare it to.”

Megalosaurs was the first dinosaur to receive its modern name. The year after Buckland published his paper about it, an English palaeontologist named Giddeon Mantel proposed the name Iguanodon for another strange creature, whose fossilized teeth resembled those of a large iguana. In 1833, Mantell used recently-discovered bone fragments to identify another new genus, which he called Hylaeosaurus.

Now, there were three new types of unusually large creatures for scientists to compare to each other, and that’s exactly what the English paleontologist and anatomist Richard Owen did. In a seminal 1842 paper, Owen pointed out similarities between these fossils. Based on these similarities, he identified all three of these creatures as Dinosauria, a new term he coined by combining the Greek words for “fearfully great” and “lizard.”

Recognizing the Megalosaurs, Iguanodon and Hylaeosaurus as members of a new group called Dinosauria was “revolutionary,” Sues says. “It suggested that once upon a time there had been animals that were extinct now,” yet in life had been “the dominant players in their respective ecosystems.”

These new discoveries captured the British public’s imagination. One of the first major pop culture references to dinosaurs was in Charles Dickens’ novel Bleak House, first published as a 20-episode serial between 1852 and 1853. The first chapter opens with the observation that “it would not be wonderful to meet a Megalosaurus, forty feet long or so, waddling like an elephantine lizard up Holborn Hill.”

The American public became particularly fascinated with dinosaurs during a late 19th-century period known as the Bone Wars, in which two U.S. paleontologists competed to outdo each other with new dinosaur discoveries. The friends-turned-rivals at the center of the Bone Wars were paleontologists Edward Drinker Cope and Othniel Charles Marsh. Beginning in the 1870s, they used their wealth and resources to fund new excavations and sabotage each other’s work.

Despite the sabotage, Cope and Marsh managed to discover over 100 new dinosaurs, including the Stegosaurus and Triceratops. With all of these discoveries, museums began featuring dinosaur bones and even reconstructions of dinosaur skeletons, allowing the public to see dinosaur fossils up close.

Paleontologists continued to make new dinosaur discoveries into the 1920s, but funding for excavations declined during the Great Depression and World War II. Public interest in dinosaurs returned in the 1970s, when paleontologists began to make more exciting discoveries, and propose theories that changed our understanding of the mighty creatures.

Back in the 1860s, English biologist Thomas Henry Huxley was a fierce defender of Charles Darwin’s theory of evolution. He was also one of the first people to note the similarities between bird and dinosaur fossils, and suggest that there was an evolutionary connection. Over a century later, American paleontologist John Ostrom revived this theory by arguing that birds were directly descended from dinosaurs.

Work by Ostrom and other paleontologists helped spark a dinosaur renaissance, both in terms of dinosaur research and public interest. This included new theories about why dinosaurs went extinct—a question that not many 19th century scholars had been interested in.

In 1980, scientists Luis and Walter Alvarez suggested an asteroid’s impact with Earth could have triggered an extinction event that killed most of the dinosaurs. Though controversial at first, the Alvarez hypothesis has since gained wide acceptance among scientists, as has Ostrom’s theory that birds evolved from dinosaurs.

The dinosaur renaissance also resulted in dinosaurs gaining more prominence in pop culture. In 1988, Universal Pictures debuted the first in a long-running series of animated children’s films about dinosaurs called The Land Before Time. In 1991, ABC started airing Dinosaurs, a sitcom about a family of (you guessed it) dinosaurs. The next year, a purple singing dinosaur launched the long-running children’s show Barney & Friends.

Perhaps the most significant piece of media to come out of the renaissance was Jurassic Park, the 1993 movie based on the 1990 Michael Crichton novel of the same name. The film and its sequels continue to shape how many people view dinosaurs, even as our scientific understanding of them has shifted. In fact, because scientists estimate that most dinosaur species remain undiscovered, it’s likely that our ideas about them will only continue to change.