At first glance, the spider in this Instagram video looks as if it is possessed, its body contorting, twisting, and splitting open. While this image can be startling, there’s no need to alert the ...

The knotty sea spider, Pycnogonum litorale, is not actually a spider, but it does represent a significant early branch in the genetic family tree that includes spiders, as well as scorpions, ticks and ...