Ancient Australian spiders feared extinct found alive

An ancient Australian spider species thought to have been wiped out by bushfires has been found alive.

Researchers from the South Australian Museum on Tuesday announced that they found two Kangaroo Island assassin spiders -- Zephyrarchaea austini -- at the end of September.

Discovered in 2010, the spider was only known to live in a small pocket in the north-west of Kangaroo Island off the coast of South Australia (SA).

When more than 200,000 hectares of the island including the spiders' habitat was burned in the 2019-20 Black Summer bushfires, the species was assumed to be extinct.

Researchers found the two individuals -- a female and a juvenile -- in a small patch of leaf litter outside the species' previously known range.

The announcement of the discovery was delayed until DNA testing could be conducted to confirm they were the right species.

"This is the first time the species has been found since high severity fires burnt their only known collecting locality. We have been surveying for the spiders since the fires, so it was an amazing feeling to finally find one," said Jessica Marsh, honorary research associate at the South Australian Museum.

"The spider lives in leaf litter that is suspended at around knee height in low lying vegetation - a habitat which is highly flammable, even in low severity fire.

"Like other species of assassin spiders, the KI (Kangaroo Island) species has a very small distributional range and restricted dispersal abilities making it particularly susceptible to major threats, such as prescribed and wild bushfires, feral pigs and increased fragmentation of native vegetation."

Assassin spiders, which were named for the way they hunt other spider species, date back to the Jurassic period.

Having discovered two individuals outside their known range, Marsh said her team will now expand their search on Kangaroo Island in a bid to guarantee the species' long-term survival.