Texas is blessed with a rich diversity of eight-legged critters. Few people realize, however, the impressive array of very different arachnids that you can find in Texas. Specifically, of the 11 orders of arachnids currently alive, Texas is the only U.S. state where you can find them all (we’re number one!).
What does that mean? I think a few examples of orders of animals that we may be more familiar with will help add significance to the statement. First example: all snakes and lizards across the world, belong to a single order: the Squamates. Example two: dogs, cats, bears, raccoons, mongooses, hyenas, and walruses all belong to a single order: Carnivora. Whales and dolphins belong to a different order, and bats belong to a third. In all, there are just under 20 mammal orders in the world (if you don’t count weird egg-laying mammals like the platypus ), and you would have to travel to several continents (and the ocean) to see them all.
But for arachnids, you can see all 11 without ever leaving the state. That’s the Texas Arachno-Challenge. So, let’s look a little closer into what it takes to meet the Texas Arachno-Challenge.
Several arachnid orders are easy and we won’t spend much time on these. If you have ever seen a spider, a daddy-longlegs (also called harvestmen), or a scorpion, you have knocked out three orders already (Araneae, Opiliones, and Scorpionida). These are abundant and widespread across must of the U.S., so we’ll move right along. Chances are, if you go outside much at all, you’ve seen a tick or gotten chiggers: there’s your 4th order (Acari), which includes all mites. These are also widespread around the world so we won’t talk about them either.
Now we’re getting into what may be new territory for some folks. Pseudoscorpions (Pseudoscorpionida) are common and widespread across the U.S. but rarely seen. They are small (most could comfortably walk around on the tip of a pencil eraser) and typically found under rocks and especially in soil and leaf litter. Several species also occur in caves, and Texas is home to one federally endangered cave-adapted pseudoscopion: the Tooth Cave pseudoscorpion (Tartarocreagris texana).
If you want to check this order off of your list, go to your nearest vegetated greenspace with a magnifying glass. Get comfortable with your face as close to the soil as your eyes can focus (a plastic tray to put some soil in may help) and patiently look through the soil and under rocks. You’ll know it when you see it: a tiny scorpion with no tail.
Not all arachnids are small. For the next three orders, which include some of our largest arachnids, your best bet is a trip to the Chihuahuan Desert of the Trans-Pecos, but to learn what other strange Texas creatures are part of the Texas Arachno-Challenge, you’ll have to wait until next week for The Texas Arachno-Challenge II.