Each spider in this group boasts an extended, arching carapace and two extra-long mouthparts (called chelicerae), creating the illusion of a “neck” and “beak.” The resemblance to pelicans is uncanny.
Writes smithsonianmag
What a strange creature. Makes my skin itch even more than normal spiders. Looks like it is from an alien planet or something.
The extra long mandibles are adapted to the Pelican Spider's prey - other spiders. As the Smithsonian Magazine writes:
The unusual appearance of Archaeid spiders, like most traits selected for in the course of Darwinian evolution, has a very practical purpose: it makes spider-vs.-spider hunting, the specialty of the pelican spider, considerably easier. Most spiders aren’t picky eaters—they’ll feed on whatever they manage to catch in their webs. If that means a little cannibalism now and then, so be it. Archaeids, for their part, eat nothing but spiders (though they try to avoid making meals of their own species). Flies aren’t even on the menu.
Having stalked or lured out a target spider, an Archaeid will strike swiftly, thrusting its two chelicerae downward to impale the prey, then holding it at a safe distance (out of range of venom or web attacks) until dead. Archaeids are by no means the only spider-killer spiders out there—the “pirate spiders” of the widespread Mimetidae family, for instance, are well known for tugging on the webs of other spiders to coax them down, then feasting on them. The bizarre “pelican” morphology of Archaeidae is what sets them apart.
Amazing!
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