44: Pseudoscorpions

I write to you from Arapahoe, Ute, and Cheyenne land. I am interested in learning about the different animals that live in the place where I was born. I want to mention that biological classification as taught by western science has its roots in racism, sexism, and transphobia – here’s a good explainer about why.

Pseudoscorpions are, as the name suggests, not scorpions at all – they are arachnids from the order Pseudoscorpiones. There are over 3300 of them, but they all are similarly shaped – tiny and with a body that resembles a scorpion lacking a tail. Most live in the tropics but they are found all over the world, including above timberline in the Rocky Mountains of Colorado. The oldest known fossil of a pseudoscorpion is 380 million years old, from the Devonian period, the time when fish first learned to walk on land. Like most arachnids, they have changed very little from their first appearance in the fossil record – I guess they are perfect and do not need to evolve?

The scorpion like “pincers” of the pseudoscorpion are actually the elongated pedipalps (second appendage on arthropods), which contain venom. The animal waits in a crevice and then grabs its prey, injecting it with the venom to incapacitate it. From there the animal drags in the prey, crushes it with another pair of limbs, and covers it in a digestive fluid that helps break down its own fluids until they are drinkable via extracellular digestion. This is likely happening every day in your home and you just aren’t observant enough to have noticed. Also you probably aren’t noticing because these arachnids really are very small.

Pseudoscorpions are in fact so tiny that they are known to grab onto the legs or other appendages of larger animals to travel – larger animals like, in Colorado, longhorned beetles. By the way, using another animal for transport is known as phoresy – a word you can remember because it contains the letters for “horsey”, an animal that humans love to practice phoresy with.

Back in 2011, a new species of pseudoscorpion was found at the Glenwood Caverns Adventure Park.