Hermit crab on physical characteristics, genetic information, and combined data, support the longstanding hypothesis that the king crabs in the family Lithodidae are derived hermit crabs and should be classified as a family within Paguroidea. Other researchers have challenged this, asserting that the Lithodidae (king crabs) should be placed with the Hapalogastridae in a separate superfamily Lithodoidea. Six families are formally recognized in the superfamily Paguroidea, containing around 1100 species in total in 120 genera. The fossil record of "in situ" hermit crabs using gastropod shells stretches back to the Late Cretaceous. Before that time, at least some hermit crabs used ammonites'
Brown recluse spider attributed to the brown recluse in the West Coast are either from other spider species or not spider bites at all. For example, the venom of the hobo spider, a common European species established in the northwestern United States and southern British Columbia, has been reported to produce similar symptoms as the brown recluse bite when injected into laboratory rabbits. However, the toxicity of hobo spider venom has been called into question as actual bites have not been shown to cause necrosis, and no such occurrences have ever been reported where the spider is native. Numerous other spiders have been