I made this graphic to showcase the incredible evolution of venom-injecting structures that these major groups of arachnids have independently arrived at.  The scorpion thru the telson, or the tip if the “tail”; the wolf spider (you can tell by the eye arrangement- check out the lower row of 4 eyes!) injects via fangs at the tip of its chelicerae.  Lastly the pseudoscorpion has venom administered via its vestigial pedipalps- it even evolved an opposable thumb to compliment it!  And we thought we were special?