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Arachnids: Pseudoscorpions

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Pseudoscorpions.

It probably does little to assuage the unsavory first impressions one has with the subject of the third group featured in this blog’s arachnid series, the pseudoscorpion, by noting that its name literally means “false scorpion.” Perhaps this is no surprise, given that without the proper context, pseudoscorpions are intimidating both in their name and in their generally “icky” appearance, armed with menacing claws, attached to a body that resembles a lightbulb made out of alligator skin. If nothing else, you’d at least be somewhat justified in being suspicious of them. Looks like a scorpion, has “scorpion” right in the name, but isn’t a real scorpion? Please. Just what is that tailless son of a bitch hiding? Maybe you doubt that there is such an animal, and the photo above simply depicts a normal scorpion, sans its stinging tail, removed by Photoshop. “What kind of rube do you take me for, blogger on the Internet?! I do not take kindly to unprovoked trickery!”, you howl, with language curiously more sophisticated than what is normal for someone so enraged.

The thing is, pseudoscorpions really are a unique group of arachnids distinct from “true scorpions.” They are partitioned off from the rest of the arachnids in their own taxonomic order, the predictably-named Pseudoscorpionida (also called Chelonethida). It is thought that in the Great Arachnid Family Tree, pseudoscorpions represent one of several springy arms forking off from a massive branch known as Dromopoda, which also includes potential sister groups like harvestmen (think daddy longlegs), “actual” scorpions (the nasty, pinchy, venomous kind), and solifugids (the infamous “camel spiders” of Internet renown, the subject of urban legends stemming from U.S. soldiers’ alleged interactions with them during the Iraq War…and a tasty snack for Bear Grylls). There is some disagreement within the scientific community about the Dromopoda division, and whether or not it is a true, monophyletic group (monophyletic meaning that it’s a defined grouping on a tree including a species and all of its descendants; for example, the grouping of “reptiles” excludes mammals and birds, and would exhibit something known as paraphyly…however “amniotes” includes ALL the descendants of the amniote common ancestor (birds, lizards, mammals, snakes, turtles, etc.) and would constitute a legitimate, monophyletic taxon), but even if Dromopoda isn’t a cohesive evolutionary unit, it is still likely that pseudoscorpions, based on a combination of morphological and molecular characters, are closely allied, evolutionarily, with many of those “Dromopodan” orders. So yes, pseudoscorpions are kissing cousins with desert-terrorizing nightmares like scorpions and camel spiders, and those gangly, spider-lookin’ things that collect as corpses in the lonely corners of your garage every summer.

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Arachnids: Amblypygids

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Arachnids.

Yes, arachnids; our eight-legged “friends” that cling to the shadowy, forgotten corners of our homes, under the damp seal of a rock, to the harsh, hot crust of the desert, and to their feathery webs, crafted overnight in our gardens. Arachnids, as a group, are not at all unfamiliar to us humans, and while, overall, the relationship between ourselves and these ubiquitous invertebrates is a bit complex, by and large in Western culture, arachnids are feared and reviled. The most familiar groups of arachnids, spiders, scorpions, ticks, and mites, have earned reputations as some of the most terror-inducing, retch-provoking, and spine-shuddering animals we encounter in our day-to-day lives. We cringe at the thought of ticks embedded in our skin, face first, bodies inflating into pulsating balloons of blood. We attempt to ignore the unsettling fact that millions of microscopic mites graze on our dead skin cells, both separated from our bodies and still attached. We regard scorpions, prehistoric beasts made of plates, claws, stingers, and venom, as symbolic of the uninhabitable desert wilderness.

And then, of course, there are the oh-so common spiders, creatures who receive reactions from humans ranging from praise for their beautiful, radial web architecture, to mild annoyance when encountering a surprise face and mouthful of this same web on a forest trail, to revulsion and a swift, life-ending blow with a shoe or newspaper (turning the hapless critter into a drab smear of entrails), to blinding, full-on arachnophobic panic. These last group of arachnids, in particular, are the animal kingdom’s ‘black sheep’ in our culture, becoming a fixture in our conceptualization of the spooky atmosphere of Halloween; curiously, along with bats, spiders are among the few living, non-fictional entities we set alongside the stereotypical ghoulish folklore characters like zombies, skeletons, witches, and sundry other monsters. Apparently, we consider spiders among the creepiest, darkest, and most unnerving of all living things.Those that fear spiders, and creepy-crawly arachnids in general, cite these creatures’ long, spindly limbs, soul-less eyes, hairy bodies, venomous fangs, fast movements, and a tendency to inhabit abandoned, abyssal areas where we are already at unease, as some the reasoning behind their prejudice. This instinctual aversion is strong enough, and prevalent enough, to inspire scores of films and literature where spiders are featured as agents of terror. Seriously. There are plenty. Of examples. Our overwhelmingly negative view of spiders, especially, obscures some of their talents, many of which are immensely useful to humans. These include the production of a silk that is tougher than Kevlar (which has instigated research into super-strong materials), and an inarguably critical ecological role that keeps populations of their prey items (insects) in check. Spiders, like most arachnids, in the immortal words of Rodney Dangerfield, “get no respect.”

Oh jeez. Are you guys happy now?

In the same way that spiders and other more familiar arachnids are misunderstood and have unrecognized, underappreciated roles in our lives, the very definition and realization of what arachnids, in the broadest sense, actually are typically is met with limited experience and knowledge. For example, most people, if prompted to “name an arachnid” would answer firstly (overwhelmingly so) with ‘spider.’ Some might follow up with ‘scorpion’, or perhaps ticks and mites…pretty much everything with eight legs and without insect-like antennae that comes to mind. However, the diversity of arachnids extends far beyond the web-bound orb weaver bobbing in the breeze in your front yard’s hedges, or the chigger causing lovely, itchy welts to form on your skin. While these groups are the most speciose, and most common accompaniment to our daily lives (good or bad), there are entire taxonomic orders of arachnids that go quite completely, and miserably, ignored.

This entry is to serve as the first in a series of explorations into the less-loved (or, perhaps, less-persecuted, simply out of unfamiliarity) arachnids.

But first, perhaps it is helpful to start with the following question: what is an arachnid, exactly?

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