A female Euoplos dignitas trapdoor spider. Supplied: Queensland Museum.
Paul Culliver and Erin Semmler, ‘Rare and giant’ trapdoor spider species, Euoplos dignitas, discovered in Brigalow Belt, ABC Capricornia, 20 March 2023
Researchers have officially described a new “rare and giant” species of trapdoor spider only found in central Queensland’s Brigalow Belt.
Key points:
- The female spiders live underground for their wholes lives and are larger and stockier than the males
- The males are more brightly coloured and spend years underground before venturing out to find a mate
- Arachnologist Michael Rix says it is likely the species is endangered due to land clearing
The nocturnal species can be found burrowed inside trapdoors about the diameter of a 50-cent piece in the black soil around Eidsvold and Monto, west of Bundaberg.
“The females, which are the larger trapdoor spiders of the two sexes, they’re almost five centimetres in body length,” arachnologist Michael Rix said.
“They’ve got these really cryptic trapdoors in these woodland habitats on the ground and most people wouldn’t even realise that they’re there.”
While the Queensland Museum‘s Project DIG team’s discovery is an exciting one, Dr Rix says the species is endangered.
“It’s rare and possibly quite threatened,” he said.
‘Dignity or greatness’
Dr Rix, the museum’s principal scientist and curator of arachnology, said the spider’s scientific name was a nod to the project and the sheer size of the animal.
“The scientific name is Euoplos dignitas,” he said.
“‘Euoplos’ is a group of trapdoor spiders – we call them the golden trapdoor spiders – and ‘dignitas’ is a Latin epithet that means dignity or greatness.”
Dr Rix said the spiders spent the first five to seven years of their lives in burrows, until the males came out and wandered the landscape to find female burrows.
“The males of this species are what we sort of call a really honey-red colour — they’re really quite stunning,” he said.
Dr Rix said the females were darker and stockier, because they spent their entire lives underground.
He said they posed no serious threat to humans.
“They have venom apparatus in the fangs, but none of the Australian trapdoor spiders in the group are known to be dangerously venomous,” he said.
“They might hurt if they bit you, but they’re not actually medically significant.”
‘A little bit concerned’
Dr Rix said scientists were concerned about the future of the species.
“Places like the Brigalow Belt have been really heavily cleared for agriculture and stock and other land uses,” he said.
Dr Rix said trapdoor spiders were suited to natural woodland remnants.
“They’re not very good at getting around the landscape and dispersing — for example, compared to a flying insect,” he said.
“They can take between five and eight years to mature and to start breeding.”
He said more surveys needed to be done in the general area.
“We’re a little bit concerned for it,” he said.
“It doesn’t seem to be doing too well in the natural environment, which is a bit of a worry.”
The confirmation of the new species was published in the Journal of Arachnology.
