Hordes of tourists descend on Cambodia every year for the sole purpose of visiting the temples at Angkor. This magnificent series of temples, carved out of the jungle in the 12th and 13th centuries by Khmer devaraja, or god-kings, is still the largest group of religious complexes ever created. Yet most visitors miss one of its more intriguing mysteries.

At Ta Prohm, near Angkor Wat and built by the epic builder king Jayavarman VII in the late 1100s, a small carving on a crumbling temple wall seems to show a dinosaur - a stegosaurus, to be exact. The hand-sized carving can be found in a quiet corner of the complex, a stone temple engulfed in jungle vegetation where the roots of centuries-old banyan trees snake through broken walls.

After parts of Tomb Raider were shot here, the temple got a PR lift and has become one of the site’s top tourist draws. But many of the package tours are still ushered in and out without spotting the enigmatic dinosaur carving.

Several different theories have been advanced to explain its presence. Some maintain it’s a recently-carved hoax, while others say that the ancient Khmers could have unearthed a fossil and figured out what kind of creature it belonged to. One theory has it that the image actually shows a cow or rhino with a palm tree in the background - the palm’s fronds being easily mistaken for the fin-like blades running down a stegasaurus’ back.

Or maybe the carving is evidence that dinosaurs really did live on until much later than previously thought. (Creationists would certainly like to believe so.) Perhaps here in the humid, ancient jungles of Southeast Asia, where the climate has remained largely unchanged since the dinosaurs’ days, giant reptiles lived on well into the human era - long enough to persist in the Khmer folk-memory. If only these walls could talk, we might have a clue.