The 50-millimetre (two-inch) spider found in Booderee National Park near Jervis Bay south of Sydney is believed to be from the Hadronyche genus, which typically lives in trees.
Until now, only the Sydney funnel-web, the ground-dwelling Atrax genus and one of the world’s most venomous, had been known to live in the park.
“It’s remarkable that we have found this… in the Booderee National Park,” said Australian National University biologist Thomas Wallenius.
“It shows we still have a lot to learn about what’s out there in the bush.
“It may even turn out to be a new species of funnel-web.”
Funnel-web spiders are feared in Australia, where there have been 13 recorded deaths from bites although none since the development of an anti-venom in the early 1980s.
Wallenius said he found the female funnel-web in the lair she had created inside a rotten log.
“They build a silk-lined burrow inside the hollow log, which can be up to two metres (yards) long. She had probably been living in there for 25 to 30 years,” Wallenius said.
“This was a big one,” he said, adding that there had been reports that there may even have been larger specimens in the area.
Wallenius said testing would be done on the spider to determine whether it fitted into current classifications.
He urged Australians not to be too alarmed, with other spiders often mistaken for their more lethal funnel-web counterparts.
“The males are more likely to be encountered in the summer months, and may be more aggressive, but contrary to common belief funnel-webs can’t jump,” Wallenius said.