The Creatures of 'Primeval' -- Dino-Sized Spiders and Centipedes

Yes, the monsters of "Primeval" are real, for the most part. And every week, KCET is educating you -- and horrifying you -- about the once-real prehistoric monsters featured on the show. Watch "Primeval" every Wednesday at 8 p.m. and then check in online to learn more!

Are you uncomfortable around spiders and centipedes and other crawly things with as many legs as they have evil plots to bite you? Yes? Well, don't read this article, for it will give you nightmares.

If you watched this week's episode of "Primeval" and you wondering whether the prehistoric bug-like creatures featured in it are real, I'm sorry to report yes: Giant spiders and scorpions did once stalk the earth, though not necessarily in the way that "Primeval" portrayed them.

First up: the "carboniferous arachnids" that infested the London Underground. These large, spider-like creatures are members of the order Solifugae that once thrived in the shady fern forests of the late Carboniferous period. "Primeval" accurately depicts that these spider-like monsters fear light. Literally, Solifugae translates as "sun-fleeing." Also accurate? The way they appear to have ten legs. Being arachnids, they only have eight, but their large leg-like sensory organs -- pedipalps -- make it look like they have ten.

Now, remember when I cautioned you against reading this post if you're squeamish about multi-legged things? This is where I really must underscore that I'm not joking, because the following information will not make you happy. Members of the Solifugae order still exist today. In fact, here's a photo of one.

A "wind scorpion" photographed in Mesa, Arizona, in 2006, via Wikipeida under a Creative Commons license.

Stop crying. They're much smaller now -- six inches max, according to Wikipedia -- and they're of little danger to humans. Still, terrifyingly, they're known in South Africa by the names haarskeerders and baardskeerders -- literally "hair cutters" and "beard cutters" -- for their supposed tendency to steal hair and fur from mammals in order to plushify their nests.

Still with me? Great.

The other creature showcased in this week's "Primeval" is the Arthropleura, a.k.a. that big freakin' centipede.
Although "Primeval" depicts them as massive, they were in reality only half that size... which puts them between seven and ten feet. Still enough to get your attention, right? Indeed, these ancestors to modern-day centipedes and millipedes were the largest-known land-dwelling invertebrates on record. But breathe easy: They're all dead now, even when they were alive, they were herbivores, and they didn't have the deadly venomous bite.

See? Don't you feel so much better?

Click here to see all of the "Primeval" creatures of the week.