Newly Found Thai Lizard Species Named After ‘House of the Dragon’ Beast

Scientists Went Looking for One Lizard in Thailand and Found a Completely New Species Instead

Deep in the mountain forests of western Thailand, scientists discovered a brand-new lizard, and named it after a dragon from House of the Dragon. Meet Acanthosaura syrax, a small, spiky-backed lizard found living above about 4,265 feet in Mae Wong National Park. Its name was inspired by Syrax, the dragon ridden by Queen Rhaenyra Targaryen, chosen for the lizard’s yellowish color, its relatively small size compared to its relatives, and its unusually high reproductive output. Notably, researchers weren’t even looking for it.

Field surveyors visiting Mae Wong National Park had been searching for a known lizard species, one that wildlife records suggested should live in that stretch of forest. They came up empty, no matter how many trips they made. Instead, they kept finding something else: a lizard with unusually tiny spines along its neck and back, unlike anything formally recorded in the group. Physical measurements and DNA analysis confirmed what they suspected. This was an entirely new species, the 23rd in the genus Acanthosaura, commonly known as mountain horned dragons or pricklenape lizards, and the findings appear in the journal ZooKeys.

Even a well-studied, protected park had one more surprise left in it.

Tiny Spines, Big Difference

Among all 23 species in the genus, A. syrax holds a record for the smallest neck and back scales yet documented. It also has a scaleless, rounded ear opening, a minimally developed throat pouch, a distinctive black collar patch on its neck, and a tail slightly longer than its body.

Researchers collected eight specimens by hand during surveys in April and May 2025: one mature male holotype and seven paratypes, made up of five mature females and two mature males. Photographs captured their coloration in life before preservation. Males displayed a dark brown marbled pattern with pale greenish spots, while females showed large whitish-yellow patterns. Both sexes lacked the black eye patch seen in several relatives, and females grew noticeably larger, reaching about 4 inches from snout to tail base versus roughly 2.7 inches in males. All eight specimens were deposited at the Natural History Museum of the National Science Museum in Pathum Thani Province, Thailand.

Researchers then compared 51 physical traits, measurements, and scale counts across those specimens against every other recognized Acanthosaura species. The new species stood apart in every meaningful comparison. Its closest lookalike is A. lepidogaster, found across parts of Thailand, Vietnam, and southern China, but even against that relative, A. syrax showed shorter tail proportions, a different scale count between its neck and back crests, and fewer scales at the chin. The team even crossed paths with A. lepidogaster itself that same season, about 31 miles north at Khlong Lan National Park, living at lower elevations in much warmer conditions. That gap between where each lizard lives adds another layer of evidence that these are genuinely different animals.

The DNA Evidence Backs It Up

Looks alone can mislead scientists, since closely related species can resemble each other and distant relatives can too. So the team ran genetic tests on all eight specimens, checking two separate stretches of DNA passed down through the mother’s line, to see how this lizard’s genetic code compared with its relatives’.

The eight A. syrax specimens were nearly identical to each other genetically, which makes sense since they all came from the same small area. Against other species, the picture looked very different. On one of the two DNA stretches researchers checked, A. syrax differed from its closest relative, A. lepidogaster, by roughly 17%, and from its most distant relative tested by close to 28%, gaps as wide as the ones that separate other species in this group. When researchers used that DNA to build a family tree showing how all these lizards are related, A. syrax landed strongly on its own separate branch. A second, independent DNA analysis pointed to the same branch, though with a less definitive statistical grade.

A New Species Already Facing Threats

Even as researchers celebrate the discovery, they flag a serious concern. Acanthosaura syrax appears confined to restricted high-elevation evergreen forest within Mae Wong National Park, and field surveys found no individuals below about 3,280 feet. The rugged mountain terrain likely keeps its populations naturally fragmented, cut off from one another by the landscape itself. That isolation could make the species vulnerable if its mountain habitat changes, especially if its range turns out to be as limited as current surveys suggest.

Researchers are calling on local authorities to strengthen protection for these forests. They’ve also suggested A. syrax join a group of threatened animals, including the Asian forest tortoise, Oldham’s leaf turtle, grey-sided thrush, rufous-necked hornbill, and Indochinese tiger, as a public symbol for conservation in Thailand’s mountain ecosystems. Neighboring mountain ranges remain largely unsurveyed, so this newly named dragon may not be alone up there for long.

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