Here are 5 new species of Australian trapdoor spider. It took scientists a century to tell them apart


A female Euoplos variabilis from Mount Tamborine.
Jeremy Wilson

Mark Harvey, The University of Western AustraliaAfter a century of scientific confusion, we can now officially add five new species to Australia’s long list of trapdoor spiders — secretive, burrowing relatives of tarantulas.

It all started in 1918, when a species known as Euoplos variabilis, was first described. Since then, this species has been considered widespread throughout south-eastern Queensland.

However, in new research, fellow arachnologists from the Queensland Museum studied the physical appearance and DNA of these trapdoor spiders. They revealed this “widespread” species is actually several.

Many trapdoor spider species are short-range endemics, meaning they only occur in one small area. This makes them especially vulnerable to threats such as habitat destruction and degradation, which is why the discovery and description of these new species from Queensland is so important — they can now be protected from future threats.

Meet Australia’s trapdoor spiders

To many people, Australia’s spider diversity is a source of fear. To arachnologists like myself, it’s a goldmine.

Weird and wonderful new species are everywhere. While new discoveries are relatively common, it’s likely most Australian spider species are still yet to be named by science.

The crenate burrow of Euoplos crenatus, a recently discovered ‘palisade trapdoor spider’.
Michael Rix

Trapdoor spiders live in burrows that usually have a hinged door at the entrance that the spider constructs using silk, soil or other material from the surrounding area. Their burrows can be camouflaged, but to a trained eye they’re easily found on the soil embankments beside walking tracks in eastern Australian rainforests.

In the past few years, I’ve been part of a team studying the spiny trapdoor spiders — a group of relatively large (up to about seven centimetres long, including legs) but highly secretive spiders found throughout Australia. They belong to an ancient group called the Mygalomorphae that, alongside tarantulas, includes the infamous Australian funnel-web spiders.

Australian spiders of the group called the Mygalomorphae: left, a funnel-web spider; middle, a wishbone spider; right, a tree trapdoor spider.
Jeremy Wilson

Like other trapdoor spiders, adult male and female spiny trapdoor spiders look shockingly different. When males reach adulthood, their physical appearance changes: their legs get longer and thinner, and their first appendages (called “pedipalps”) develop into structures used for mating. In contrast, adult females remain short-legged and robust.

Male trapdoor spiders undergo this dramatic change because as adults they must leave their burrow and search for females to breed.

Their long legs presumably help them run faster and further in search of females, and also allow them to keep the vulnerable parts of their body out of harm’s way once they meet the (usually larger) female, who isn’t always happy to see them.

The mystery of the trapdoor spider from Mount Tamborine

This striking differences in appearance between male and female spiny trapdoor spiders (“sexual dimorphism”) was at the heart of the mystery regarding the true identity of Euoplos variabilis.

A male and female of the same species of trapdoor spider, showing the sleek, long-legged male and the robust female.
Jeremy Wilson

When the species was first described in 1918, it was based only on female spiders, which were red-brown, large and lived in the rainforest of Mount Tamborine, just south of Brisbane.

In 1985, a male spider, also from Mount Tamborine, was finally linked to the original females. Matching male and female trapdoor spiders of the same species can be difficult because they look so different.

This all changed when the Queensland Museum team began researching the spiny trapdoor spiders of eastern Australia in 2015. When they looked in the museum’s natural history collection, it seemed like males of the Mount Tamborine trapdoor spider were widespread, spanning Brisbane to the Sunshine Coast.




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But strangely, they found females from different locations looked different.

While females from the Mount Tamborine rainforest were large and red-brown, those from the lowlands of north Brisbane were small and tan. And in the rainforest of the D’Aguilar Range, north of Brisbane, the females were even bigger, with a bright orange carapace and red legs.

Could these really all be the same species?

One of the males originally thought to be Euoplos variabilis. It was later realised these males belong to an entirely different species, now called Cryptoforis hughesae.
Michael Rix

This mystery was solved in two steps

First, in 2018, the museum’s arachnologists discovered the seemingly widespread males were actually members of a completely different group of trapdoor spiders, which also occurs in eastern Australia. In other words, there had been a male/female mismatch!

Then, by collecting fresh trapdoor spiders around south-east Queensland and studying their DNA, they discovered the Mount Tamborine trapdoor spider actually doesn’t occur in Brisbane at all. In fact, it’s found only in the mountain ranges bordering New South Wales, with Mount Tamborine being its the most northerly location.

Surprisingly, the female spiders found in Brisbane, the D’Aguilar range, and in various other areas, turned out to be several completely different species, new to science.




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These species can be distinguished by subtle differences in size and colour, and by differences in their DNA. The different species seem to be adapted to different habitats, at different elevations.

So, alongside Euoplos variabilis, the original Mount Tamborine trapdoor spider, the new confirmed species are:

  • Euoplos raveni and Euoplos schmidti, both from the lowland forests of the Brisbane Valley, south of the Brisbane River
  • Euoplos regalis from the upland rainforest of the D’Aguilar Range
  • Euoplos jayneae from the the lowland forests of the Sunshine Coast hinterlands
  • Euoplos booloumba from the upland rainforest of the Conondales Range

These five new species put the total number of known spiny trapdoor spider species to 258.

Don’t be alarmed, bites from a trapdoor spider aren’t dangerous to humans.
Shutterstock

What happens now?

And so, the mystery was solved. Another small fraction of Australia’s beautiful biodiversity is known to science and can be preserved. But the story isn’t over just yet.

To properly conserve these species, we need to understand more about how they live. This is why the research team and I are undertaking a long-term study on one of these new species, Euoplos grandis from the Darling Downs. We hope to learn the intricacies of their lives and to track whether populations are declining from threats such as habitat destruction.




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We’re also continuing our mission to discover and describe new species of trapdoor spider, not just from Queensland, but from all around Australia.

The story of the Mount Tamborine trapdoor spider exemplifies the type of detective work Australian scientists undertake on all types of animal groups. But when it comes to invertebrates, we’ve barely scratched the surface, with new species of bugs, spiders, worms and more waiting to be discovered.

Working on discovering these invertebrates comes with a sense of urgency. These species need a name and formal protection, before it’s too late.

Who would win in a fight between a scorpion and a tarantula? A venom scientists explains for The Conversation.

Jeremy Wilson and Michael Rix from Queensland Museum were co-authors on this articleThe Conversation

Mark Harvey, Curator of Arachnology at the Western Australian Museum, Adjunct Professor, The University of Western Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Trapdoor spider species that stay local put themselves at risk



File 20190405 123397 omwexr.jpg?ixlib=rb 1.1
A palisade trapdoor spider of the new species E. turrificus walks across the rainforest floor near Maleny, Queensland.
Jeremy Wilson, Author provided

Jeremy Dean Wilson, Griffith University

Several new species of trapdoor spiders found in Queensland are finally described in an article published this month in Invertebrate Systematics.

But each of the new species occurs in only its own single, isolated patch of rainforest in southeastern Queensland, and nowhere else.

Because these species have such tiny natural distributions, they are especially vulnerable to extinction.




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Unique spider burrows

These newly described spiders have been given the common name palisade trapdoor spiders because of the strange and unique burrows they construct. The entrance to the burrow projects out from the surrounding soil like a miniature turret.

The remarkable palisade burrows constructed by two different species of palisade trapdoor spider. The burrow entrances project from the surrounding soil.
Jeremy Wilson (left), Michael Rix (right)

Not only that, but each of the four new palisade trapdoor spider species constructs its own unique type of burrow.

One species, found in national parkland near Gympie and known scientifically as Euoplos crenatus, constructs a particularly elaborate burrow. The hinged door that covers the burrow entrance is adorned with several rounded lobes which project from the door’s circumference.

This marvel of natural architecture is constructed by the spider using silk and soil. No other spider species in the world constructs something similar.

This species was originally discovered by local naturalists Kelvin and Amelia Nielsen in 1999, who then guided researchers back to the discovery location in 2016 to collect specimens so the species could be formally named.

The burrow entrance of Euoplos crenatus, with its peculiar ‘crenate’ burrow door.
Michael Rix

Another species, Euoplos thynnearum, constructs a burrow entrance with a thick lip within which the burrow door sits. It’s found in the Mary Cairncross Scenic Reserve, a 55-hectare patch of subtropical rainforest popular with visitors to the Sunshine Coast hinterland.

This species is named after Elizabeth, Mabel and Mary Thynne, who originally donated the reserve land to the local council in 1941 to honour their mother Mary Thynne (née Cairncross). Currently, this species is known to occur only within the reserve and in other rainforest patches in the immediate vicinity.

Burrow entrances of the new palisade trapdoor spider species Euoplos thynnearum. This species is largely restricted to a single rainforest patch, occurring within Mary Cairncross Scenic Reserve near Maleny.
Michael Rix

Short-range species at risk

Species that only only occur in a very small area, like these new palisade trapdoor spider species, are known as short-range endemic species.

Although scientists are naming new species at a faster rate than ever before, estimates of the total number of species on Earth still suggest that most animal species have not been formally named. With so much work still to do, some scientists have chosen to prioritise work on particular types of animals that are especially vulnerable to extinction.

In 2002, Mark Harvey, an arachnologist from the Western Australian Museum, proposed that scientists should prioritise the discovery and description of short-range endemic species.

He reasoned that the small ranges of these species make them inherently vulnerable to extinction, and that identifying, naming and studying them is the first step to protecting them.

The strange burrows of the trapdoor spider species Euoplos crenatus project out from between the roots and leaf-litter on the bank of a creek in a rainforest patch near Gympie, Queensland.
Jeremy Wilson

Staying local

For trapdoor spiders, short-range endemism is the rule, not the exception. These spiders live their entire lives in a burrow. Juvenile spiders walk only short distances from their mother’s burrow, before constructing a burrow of their own.

Usually, these spiders will then remain in the same burrow for the remainder of their lives, enlarging it as they grow.

Examples of different trapdoor spider species from eastern Australia. Top left, Arbanitis longipes; top right, Heteromigas sp.; bottom left, Cataxia sp.; bottom right, Namea sp.
Jeremy Wilson

Adult male trapdoor spiders will also leave their burrow to breed, but will only travel relatively short distances. Over time, this extremely limited dispersal ability has led to the evolution of many different trapdoor spider species, each of which occurs in only a very small area.

Since 2012, a research team, led by Queensland Museum researcher Michael Rix, has been trying to discover and name all species of spiny trapdoor spider – this group includes the palisade trapdoor spiders, as well as other strange trapdoor spider species such as the shield-backed trapdoor spiders of Western Australia.

A shield-backed trapdoor spider from Western Australia, showing the distinctive hardened disk on its abdomen which the spider uses to ‘plug’ its burrow as a protection from predators.
Mark Harvey

So far, this project has led to the description of more than 100 new species from throughout Australia, some of which are already classified as threatened by federal and state governments.




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The most iconic of these is Idiosoma nigrum (also a shield-backed trapdoor spider), which is a listed threatened species.

The discovery of all these weird and wonderful spider species should remind us that Australia has some of the most remarkable invertebrate species in the world, and new species are waiting to be discovered in the national parks and reserves which occur around, and even within, our towns and cities – under our noses.

Next time you visit a national park, or drive past a patch of forest while commuting along Australia’s east coast, think to yourself, what might be living in there? Do those species occur anywhere else? And above all, if we lose that forest remnant, what unique species might disappear along with it?The Conversation

Jeremy Dean Wilson, Ph.D candidate, Department of Environment & Science, Griffith University, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.