From Down Under to underground: Surprising daddy long-legs spiders discovered in Australia and Réunion

Australia's rich and diverse fauna never fails to surprise us, as a new spider species has been documented from the continent.

The novel species, a blind daddy long-legs, was found in boreholes in the arid Pilbara of Western Australia. It is the first cave-adapted daddy long-legs spider reported from the continent, with other blind species of its genus so far only found in Thailand, Laos, and Vietnam.

"It represents a subfamily that was previously thought to be restricted to the tropical north and east of the continent," says Bernhard Huber, one of the authors of a recent study published in the journal Subterranean Biology.

"The new species suggests that these spiders were widely distributed in Australia before the continent's aridification in the last tens of millions of years," he adds.

Together with it, another extraordinary daddy long-legs species was described as new-to-science from Réunion island. It was collected in the Grotte de La Tortue, a 300,000-year-old lava tube. Its closest known relatives are in eastern Africa, which begs the question how the species reached the island.

The researchers believe its ground-dwelling ancestor arrived to Réunion "relatively recently and by highly accidental means (such as rafts or storms)" but adapted quickly to subterranean life.

"If our generic assignment is correct, then the ancestor of Buitinga ifrit must have reached Réunion from East Africa within the last few million years," they write in their paper.

Curiously, both spiders were named after mythical underground dwellers: Belisana coblynau, after "the mythical gnome-like creatures that are said to haunt mines and quarries," and Buitinga ifrit, after "a demon in Islamic mythology that is often associated with the underworld."