sentences:  However, a comprehensive fossil record of jumping spiders from erstwhile Gondwana is only known from long after the supercontinent's breakup in the late Mesozoic, even though fossils of ancient jumping spiders are not infrequently found on the northern continents.Thus, if the Amycoida originated by dispersal over a fairly short stretch of open ocean, the Salticoidea are almost certainly of North American origin.On the other hand, spiders, even if they spin no webs, are excellent at dispersing across extreme ranges by ballooning along the atmospheric circulation as juveniles.