'Almost certainly new' species of giant earthworms found in SA

Giant earthworms found in SA 'almost certainly' a new species Sun 19 Jul 2026 at 8:00am In short: An insect ecologist has been monitoring giant earthworm sightings across South Australia for 30 years, despite the species not formally being recognised in the state. According to a scientist and environmental consultant, the massive creatures are an "almost certainly new" species. What's next? Recognising a new species involves research and the publication of a scientific paper. Officially, giant earthworms do not actually exist in South Australia. Anecdotally, there have been dozens of encounters with the elusive creatures, according to ecologist Kristen Messenger. She has spent the past 30 years keeping track of giant earthworm sightings which, according to some accounts, are "more than a metre long" and as "thick as a garden hose". "Google will tell you that there are no species described in SA, but I don't think that's true,"Ms Messenger said. "As an ecologist, you get a lot of people telling you things that can't be true or that are probably a bit exaggerated." But then she found a few of the giant earthworms herself. And she had the photos to prove it. While common earthworms average less than 15 centimetres long, the worms Ms Messenger was hearing about were anywhere from 70cm to a metre-and-a-half long. The biggest one she had seen evidence of appeared to be about 2 metres long, and was found in the Mid North. South Australia is known to have one species of larger earthworm, the Giant Mount Lofty Earthworm, which was identified in 1887 and is known to live in the Adelaide Hills and Mount Lofty Ranges. But Ms Messenger's reports have come from all around the state, though were concentrated in semi-arid regions like the Flinders Ranges. A social media call-out by ABC North and West received reports of giant worms from across the state: the Mid North, Adelaide Hills, Southern Flinders Ranges, Yorke Peninsula, Murray region, Eyre Peninsula, Barossa, and Fleurieu Peninsula. What's in a species? CSIRO visiting scientist and environmental consultant Geoff Dyne identified a new species of giant earthworm in Broken Hill in 2021. He said some of the big worms found in South Australia are "almost certainly new" species. "We haven't got any records really in those more arid regions. So anything that we come across that's unusual and apparently not in the right sort of habitat, you … have a good chance of being an undiscovered or new species," Dr Dyne said. "The two-metre one would be certainly a new species… we haven't got anything on that scale known from South Australia. "Whereas, the smaller ones could be the same species as the Mount Lofty one. "That can only be ascertained by close examination, anatomical dissection, and then you know what you're dealing with." Under the International Code of Zoological Nomenclature, the recognition of a new species requires paper publication in an accredited journal. Loading...It is a process Dr Dyne went through for the Broken Hill earthworm (Aridulodrilus molesworthae), adding to the more than 700 known native earthworm species in Australia. "We have our fair share of giant earthworms in Australia, but the trouble is that they're rarely seen," he said. "There are doubtless more that we don't know about. "We need to know more about what we actually have before we lose it. "We've probably lost a lot already, which we don't know about, and never will, because of land clearing across the whole continent." The secret society of earthworms So how has such a big worm gone undiscovered for so long? A big part of it could come back to South Australia's environment, according to Dr Dyne. "South Australia has always been thought to be pretty depauperate as far as earthworm populations are concerned, because it is one of the driest states," he said. Ms Messenger thinks it is partly due the worms' elusive and hidden nature. "They're hiding down in the soil, they're doing all this incredible work, and no one sees them doing it. They're out of sight, out of mind," she said. Like other recognised giant worm species, the South Australian giant earthworms normally only come to the surface at night, spending their days in permanent burrows up to three metres below the soil. But recent heavy rains could lead to daytime sightings. "The only time you'll see them in the day is if the soil is so saturated that it's reached absolute saturation point, and then they have to come up because they'll drown," Ms Messenger said. "I have a gut feeling there is probably tonnes and tonnes and tonnes of giant worms in Australia and we've just never noticed them." Though she may be the most qualified to carry out the work required to get these giant worms recognised in an official capacity, Ms Messenger has no plans of turning to academia anytime soon. "A different person might preserve their giant worm in fluid and try to describe it, but that doesn't interest me," she said. "I'm just really interested in the intrinsic value of them as creatures. I just love them, they're so exciting."