Discovery on museum shelves hints at presence of 250 unknown scorpion species

Researchers initially thought they were looking at one species of scorpion, but they quickly realised there were crucial differences among the specimens.

Take a stroll through a museum anywhere in the world and you’ll catch adults and children alike gawping and marvelling at the creatures on display. But it was the genitals of one tiny West Australian scorpion that had researchers’ jaws dropping in disbelief — with a discovery that will spark wider ramifications for our understanding of the species.

It was only after studying the male scorpions’ genitalia that it became clear they were looking at two separate species, and not one as previously thought leading to newly described Urodacus uncinus and Urodacus lunatus scorpions species. It’s the first time scientists used male reproductive anatomy to distinguish scorpion species, and this hints there is likely more variability amongst Australian populations.

Jars on a shelf at the Museum of WA containing scorpions.
A discovery was made after scorpion samples were analysed by taxonomists. Source: Museum of WA

Despite both new species being the size of a human hand and brandishing massive venomous tails, very little is known about the rarely seen creatures, as like trapdoor spiders they live in burrows underneath the ground. The specimens had mostly been collected during mining surveys in a tiny corner of Western Australia’s remote Pilbara and no more than 50 individuals have been captured and stored over the last 20 years at the Museum of Western Australia.

Lead researcher and Flinders University evolutionary biologist Dr Bruno Buzatto told Yahoo News Australia he’s never seen a living example of either species, which belong to the Urodacus genus. The closest he's come to seeing one in the wild was a photo a miner showed him of a recently drowned Urodacus scorpion in a pool.

Only 47 species have been described in Australia, and there are countless specimens on museum shelves waiting to be examined around the country.

Buzatto and his team published their findings about the two new species in the Australian Journal of Zoology in November. In January, they revealed in The Conversation the discovery of the tiny detail separating the species led them to suspect Australia could be home to 500 species of scorpion, double what was previously thought to exist. That means there could be over 450 yet to be named.

Online scorpion trade a threat to species

It’s only after a species is described that governments can step in and protect them. It’s likely Australia has lost several species of arachnid and insect before they were known to science.

“Like trapdoor spiders and tarantulas, these scorpions have very poor dispersal ability. We show with this study that both species are only known in small areas, one only in a 50 square kilometre area between collection points,” Buzatto said.

Dr Bruno Buzatto holds a specimen jar containing a scorpion. Inset - a scorpion against a white background.
Dr Bruno Buzatto and scientists from Murdoch and Flinders Universities described the two new species of scorpion. Source: Supplied/Australian Journal of Taxonomy

“We need to go through the rest of the museum collection so that we know which areas contain a lot of short-range endemic species so we can preserve them. But we need the funding to do that.”

Background - the Pilbara desert. Foreground - Urodacus lunatus males compared with Urodacus uncinus males against white backgrounds.
Can you spot the difference? Urodacus lunatus (right) and Urodacus uncinus (left) were originally thought to be the same species. Source: Australian Journal of Taxonomy/Huon L Clark

Scorpion species that live in a small range are susceptible to natural disasters and habitat loss. Collectors who take them from the wild and sell them online or in pet shops are also a threat, and across much of Australia a permit isn’t required to do so, except for inside designated conservation areas.

That’s particularly concerning for the two newly described species of Urodacus, because two closely related scorpions from this family are among some of the most frequently traded online.

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