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'
White-browed hermit the very similar Reddish Hermit ("Phaethornis ruber") which generally occurs at lower elevations, and identification criteria between the two species is still not well known. White-browed Hermit may be slightly paler with more bronze coloration in the tail. The range extends along the base of the Andes from central Peru south to central Bolivia, in an elevational band from 350 m to 1400 m. The species is generally encountered most often within forest interior, although individuals occasionally forage along forest edge. Like most hummingbirds, it feeds mostly on nectar from a variety of flowers, but also consumes some small insects.