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'
Rufous-breasted hermit attached to the underside of a palm, fern or "Heliconia" leaf one or two meters (3–6 ft) above ground or so. The nests are often near a stream, waterfall or roadside, and are surprisingly easy to find. Incubation is 17 days with 23 more to fledging, and this species may nest up to four times in a season. The male of this aggressive and inquisitive hummingbird helps to build and defend the nest, but does not incubate the eggs. At least regionally (e.g. in Colombia), the species breeds all year. Rufous-breasted hermit The rufous-breasted hermit or hairy hermit ("Glaucis hirsutus")