Bark Crab Spider

In addition to Ground Crab Spiders (Xysticus), we also have Bark Crab Spiders (Bassaniana), so-called because of the extensive mottling on the legs and abdomen, as well as the black, flat carapace, which provides good camouflage against the bark of trees.

While walking the dogs in the front yard, I came upon an interesting sight in the driveway: a Bark Crab Spider (Bassaniana versicolor) was hanging from the smooth white bumper of our SUV. Spidey was having a hard time of it, however, owing to a missing second left leg, and was consequently twirling around, clambering up the side, and lowering itself down on a line, seemingly not quite sure what it wanted to do. What it expected to catch on the bumper, no one knows.

Just hangin' around...

At the moment I'm not ruling out Bassaniana utahensis, or a hybrid of that and B. versicolor. But I believe versicolor is the most likely species.

References:
http://bugguide.net/node/view/87495 (helpful info on how to ID Bassaniana spp.)
http://bugguide.net/node/view/59050 (B. versicolor)
http://www.pbase.com/tmurray74/crab_spiders_thomisidae (photo gallery of Thomisidae)