In Madagascar, scientists are learning about the pelican spider – a creature that looks like a bird and preys on its own kind.

On the island of Madagascar, scientist Hannah Wood is on the trail of a ruthless killer. First discovered encased in amber in the 19th century, it’s a creature that has fascinated Wood throughout her career. And now, she has managed to track it down – learning more about this strange species than ever before.

Located in the Indian Ocean, some 250 miles from the eastern coast of Africa, Madagascar was once part of Gondwana, a supercontinent that covered almost 40 million square miles. But 135 million years ago, the landmass split in two. And more than 45 million years after that, Madagascar separated from India to form an island of its own.

Because of its unique geological past, Madagascar has become a haven where unusual flora and fauna have flourished over eons. Evolving in an environment comparatively isolated from the rest of the world, many of the island’s plants and animals have developed traits and quirks that have fascinated scientists for generations.

Today, Madagascar is home to some 200,000 animal species – of which around 150,000 are unique to the island. And according to experts, there are many more waiting to be discovered. Moreover, while some of the species are instantly recognizable, others appear so weird and wonderful that they might as well have come from an alien planet.

With so much diversity, it comes as no surprise that scientists from all over the world dedicate their careers to studying the plants and animals that thrive on Madagascar. Among them is Hannah Wood, a biologist with the prestigious Smithsonian Institution in Washington, D.C.

Growing up in the rural community of Sky Forest, California, Wood had an interest in animals and the great outdoors. And after studying English Literature at the University of California, she went on to gain a PhD from the college’s Environmental Science, Policy and Management department.

Apparently, it was while Wood was working on her masters that she first encountered a strange type of arachnid found on Madagascar. Known as the pelican spider, at the time it was thought to consist of just one genus. That would be the Eriauchenius, a creature sometimes referred to as an assassin spider.

In 2015 Wood joined the Smithsonian as Curator of Arachnids and Myriapods, specializing in creatures such as scorpions, spiders, millipedes and centipedes. There, she began to study how arachnids have diversified over the centuries. In particular, she looked at the ways in which they have changed their feeding habits as they have evolved.

Image: Jeremy Miller via Smithsonian.com

Three years later, Wood published a paper in ZooKeys, a journal dedicated to zoology and related topics. And in it, she revealed the details of Madagascarchaea, a genus of pelican spider believed to be quite distinct from Eriauchenius. In fact, the paper is the first time that the creatures have ever been described.

Image: Nikolaj Scharff via Natural History Museum of Denmark

During Wood’s research, she drew upon an inventory of Madagascan arthropods – the category to which spiders belong – assembled by the California Academy of Sciences in 2000. Additionally, she also conducted fieldwork on the ground in Madagascar, collecting examples of pelican spiders to help with her studies.

Typically less than 0.3 inches in length, pelican spiders get their name from their distinctive appearance. Equipped with a long carapace – the hard shell that sits on top of the body – and two extended mouth-parts known as chelicerae, these creatures bear a remarkable resemblance to the large-beaked birds.

Image: Nikolaj Scharff via Natural History Museum of Denmark

Officially called Archaeids, experts believe that these creatures could have been around since the time of Pangaea – a supercontinent that once covered much of the southern hemisphere. And amazingly, this means that they might have been crawling the earth for at least 180 million years.

It’s thought, in fact, that pelican spiders have existed for longer than the big-beaked birds they’re named after. Back in 1854, researchers stumbled upon a specimen encased in amber, thought to date back to the Eocene Epoch some 50 million years ago. And later, some even older examples emerged.

After that first discovery, researchers uncovered more evidence of pelican spiders, this time in amber estimated to date from around 95 million years ago. Furthermore, experts believe that they may also be present in compression fossils dating back a staggering 165 million years. With this in mind, it seems entirely possible that the creatures could have existed while Pangaea was still whole.

It took almost 30 years, however, before the first living Archaeids were found in Madagascar in 1881. Interestingly, they have also been discovered in Australia and South Africa over the years – lending further weight to the idea that these creatures evolved while those regions were still connected by land.

Apparently, the unusual appearance of pelican spiders isn’t just for show. Their extended carapace and chelicerae, in fact, serve a practical purpose, enabling them to stalk their prey with ease. “These spiders attest to the unique biology that diversified in Madagascar,” Wood told Phys.org in 2018.

But what exactly does a pelican spider eat? Unlike many other arachnids, which feast on whatever they are able to catch, Archaeids maintain a strictly cannibalistic diet. In fact, they even steer clear of flies – a diet staple for many of their kin. Instead, they follow the silk drag-lines that other spiders leave behind to find their way to their next meal.

Once a pelican spider has honed in on a target, it then impales its victim on its chelicerae. From there, the arachnid keeps its prey at arm’s length until it expires. According to experts, this technique ensures that the hunter is protected from any venom that might be released as its prey fights for its life. Safe from harm, the Archaeid merely waits for an easy meal.

But while pelican spiders were classified over a century ago, Wood made some startling observations about these distinctive beasts. For example, while the Archaeids of Australia and South Africa tend to be quite similar in appearance, those in Madagascar display an impressive amount of diversity.

According to Wood, this diversity could be a direct result of the island’s interesting history. “Madagascar had many more ancient geological and climatic events,” she told Smithsonian.com in 2018. “Whereas in South Africa and Australia, it was very recently that you had some major climatic events, such as the aridification of Australia and the uplift of mountains in South Africa.”

Essentially, this means that the pelican spiders of Madagascar have had plenty of opportunity to develop their own biological niches in response to their altered environment. However, for the Archaeids of Australia and South Africa, these changes are still relatively recent – hence their homogeneous appearance.

Using an electron microscope, Wood applied various techniques in order to study and classify the pelican spider samples in her possession. For example, she often looked at the creature’s genitals to determine whether they were of compatible shape. If so, it’s strong indicator that they belonged to the same species.

In fact, the diversity of Madagascar’s pelican spiders is startling. In Wood’s paper, she described no less than 18 new species of Archaeid – four of which belonged to the new genus, Madagascarchaea. And when it came to naming them, the biologist resorted to some creative means.

One of the creatures, dubbed Eriauchenius miljaneae, was named after Wood’s daughter, Mila Jane. Elsewhere, E. wunderlichi paid tribute to a famous arachanologist, while E. rafohy’s moniker was inspired by a Madagascan queen from the 16th century. So far, however, Wood has yet to name a spider after herself – although there’s still time.

In fact, Wood believes that Madagascar has many more secrets left to reveal. “I think there’s going to be a lot more species that haven’t yet been described or documented,” she told Phys.org. Meanwhile, the pelican spiders that featured in her study have been moved to a new home.

The arachnids will soon find themselves as part of the Smithsonian’s National Entomological Collection. Wood’s specimens will, in fact, become part of one of the world’s biggest collections of insects. After preservation, they will be stored in the archives for posterity where future generations of researchers can learn from their unique biology.

Image: Andreas Kay via Twitter/Ferris Jabr

However, pelican spiders are far from the only creatures that take on the appearance of another, entirely different, animal. For example, on October 31, 2018, writer Ferris Jabr tweeted a photograph of a bunny harvestman – a type of arachnid that’s loosely related to spiders.

Equipped with eight spindly limbs, the bunny harvestman doesn’t look dissimilar to the harvestman known as a daddy longlegs. However, there is one major difference. On top of the creature is a mass that bears an uncanny resemblance to the head of a black dog – complete with sinister yellow eyes.

The effect is so startling that some social media commenters have, in fact, insisted that the image had been created using Photoshop. However, Jabr maintained that it showed a real creature. And this creepy harvestman was snapped by wildlife photographer Andreas Kay in 2017 in the Amazon.

But just like the pelican spider, the bunny harvestman’s strange appearance likely serves an evolutionary purpose. Experts, though, are currently unsure as to what that might be. In an online blog in 2017, Kay speculated that some of the creature’s markings might be used to confuse any potential hunters.

“Maybe the eye spots and ear-like protuberances are meant to fool predators into thinking the creature is larger than it really is,” Kay wrote. Also found in butterflies, fish and birds, eye-like markings aren’t that unusual in the animal kingdom. They create the illusion of something bigger – thus presenting a more intimidating challenge.

Interestingly, it’s not only arachnids that make a habit of disguising themselves as other creatures. The hawk-moth caterpillar, for example, utilizes a similar technique to the bunny harvester. The large eye-spots on its body are there to present the appearance of a snake to potential predators.

Perhaps the most well-known example of an animal that disguises itself to look like another is the mimic octopus. Discovered in 1998, this bizarre cephalopod is able to adapt its appearance to resemble a whole menagerie of creatures, including a lion fish, a jellyfish and even a sea snake.

For the mimic octopus, its ability to resemble other, often poisonous, creatures is an important survival tool. By convincing predators that it is far more dangerous than it really is, it can ensure that they give it a wide berth. Moreover, it has also been known to practice aggressive mimicry, lulling prey, such as crabs, into a false sense of security by taking on the appearance of a potential mate.

Weird mimicry in nature is not just limited to creatures that take on the appearance of other species, however. In fact, some of the animal kingdom’s strangest inhabitants are those that recreate completely inanimate things – such as the peanut bug, an insect found in the tropical regions of the Americas.

At less than four inches long, the Fulgora laternaria, or peanut bug, boasts a protuberance on its head that closely resembles the nut from which it gets its nickname. And although this gives it a rather cumbersome appearance, the peanut comes equipped with its own false eye-spots. As with other animals, this gives predators the impression that the creature is far larger than its actual size.

Elsewhere, other animals use a process known as mimesis to mimic their natural surroundings. This enables them to blend into the background and pose a frustrating challenge to any predators looking for a meal. For example, the forest leaf grasshopper perfectly recreates the appearance of foliage, while the tree stump orb weaver spider can easily disappear against a gnarled piece of wood.

Amusingly, there are even creatures that mimic some of the less salubrious elements of the animal kingdom. Celaenia excavata, otherwise known as the bird dropping spider, is notable for its somewhat gruesome markings. Believe it nor not, they recreate the appearance of, ahem, excrement in order to dissuade predators from tucking in.

Back in Madagascar, the discovery of new species of pelican spiders has served to remind experts just how fragile this island habitat can be. And according to the Western Australian Museum’s senior curator of arachnids and myriapods, Mark Harvey, it’s an indicator of the vital importance of preservation work.

“Each of the Malgasy species is found in a relatively small area of the island,” Harvey told National Geographic magazine in 2018, “highlighting that ongoing habitat loss is likely to significantly affect these fascinating spiders. Let’s hope that none of them become extinct due to ongoing logging and burning.”