Is it possible that trapdoor spiders plug their burrow when it gets too dry to conserve water? Must investigate...
This differs from other trap doors I've found in that it's so obvious! There were two right next to each other, and both had this kind of "plugged" structure, with the door fitting nicely in the tunnel entrance. Previous trap doors I've found were in Las Trampas, and on both the door was a flap that covered the burrow entrance entirely (and making them almost impossible to see). Not sure if this is a significant difference or not. I guess the only way to tell would be to dig them out.
The wafer trapdoor spiders (superfamily Cyrtauchenioidea, family Cyrtaucheniidae) are a widespread family of spiders that lack the thorn-like spines on tarsi and metatarsi I and II (the two outermost leg segments) found in true trapdoor spiders (Ctenizidae).
