Nearly 130 years ago, Italian explorer Elio Modigliani arrived at a natural history museum in Genoa with a lizard he had reportedly collected from the forests of Indonesia.

Based on Modigliani’s specimen, the striking lizard — notable for a horn that protrudes from its nose — got its official taxonomic description and name, Harpesaurus modiglianii, in 1933. But no accounts of anyone finding another such lizard were ever recorded, until now.

In June 2018, Chairunas Adha Putra, an independent wildlife biologist conducting a bird survey in a mountainous region surrounding Lake Toba in Indonesia’s North Sumatra, called herpetologist Thasun Amarasinghe. Near the lake, which fills the caldera of a supervolcano, Putra had found “a dead lizard with interesting morphological features, but he wasn’t sure what it was,” says Amarasinghe, who later asked the biologist to send the specimen to Jakarta.

It took only a look at the lizard’s nose-horn for Amarasinghe to suspect that he was holding Modigliani’s lizard. “It is the only nose-horned lizard species found in North Sumatra,” he says.

Wooden arts and folk tales of the Bataks — indigenous people native to the region — show that lizards have a special place in the people’s mythology. “But simply there was no report at all about this species” following Modigliani’s, says Amarasinghe, of the University of Indonesia in Depok.

He asked Putra to get back to the caldera to see if there was a living population. After five days, Putra found what he was looking for one evening, “lying on a low branch, probably sleeping,” the biologist says. He took pictures of the lizard and measured the size and shape of its body parts, such as the length of its nose-horn and head. He also observed its behavior before finally releasing it the same night.

Using this data, Amarasinghe compared the lizard with the one described in 1933, and concluded that the living lizard and the dead one that Putra had stumbled across were Modigliani’s nose-horned lizards. The Genoa museum’s dead specimen is pale blue due to preservation, but it is now known that the lizard’s natural color is mostly luminous green. Its camouflage and tree-dwelling behavior are similar to African mountain chameleons, Amarasinghe, Putra and colleagues report in the May issue of Taprobanica: The Journal of Asian Biodiversity.

The reptile belongs to the Agamidae family of lizards, which are commonly called dragon lizards and include species such as bearded dragons. Shai Meiri, a herpetologist at Tel Aviv University, has previously shown that many dragon lizards live in small, hard-to-access areas, making the reptiles difficult to study. There are 30 agamid species that have never been seen since they were first described, and 19 species that are known from just a single specimen, Meiri says.

While thrilled with their find, Amarasinghe and Putra are worried about the lizard’s future. “The living dragon was found outside a conservation area, and massive deforestation is happening nearby,” Amarasinghe says.

But the rediscovery offers a glimmer of hope for the lizard’s conservation, Meiri says. Before the reptile resurfaced, no one knew where Modigliani’s lizard lived, or whether it had gone extinct, he says. But now, “we can study it, understand its conservation needs and hopefully implement conservation measures.”