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'
Stripe-throated hermit been considered a subspecies of the little hermit ("P. longuemareus"), but morphological data suggest it may be closer to the grey-chinned hermit ("P. griseolaris"). At present most, if not all, major authorities accept the split (SACC, the Clements check list, the Howard & Moore check list, etc.). It has been suggested that the mainly Central American taxon "saturatus", which typically is considered a subspecies of "P. striigularis", may deserve species status, in which case it would become the dusky hermit or Boucard's hermit ("P. saturatus"). The taxon "adolphi" is considered a junior synonym of "saturatus" by most authorities. It occurs