Hermit crab shells instead, as shown by a specimen of "Palaeopagurus vandenengeli" from the Speeton Clay, Yorkshire, UK from the Lower Cretaceous. Hermit crab Hermit crabs are decapod crustaceans of the superfamily Paguroidea. Most of the approximately 1,110 species possess an asymmetrical abdomen that is concealed in a scavenged mollusc shell carried around by the hermit crab. Most species have long, spirally curved abdomens, which are soft, unlike the hard, calcified abdomens seen in related crustaceans. The vulnerable abdomen is protected from predators by a salvaged empty seashell carried by the hermit crab, into which its whole body can retract. Most frequently,
Spider wasp Spider wasp Wasps in the family Pompilidae are commonly called spider wasps or pompilid wasps. The family is cosmopolitan, with some 5,000 species in six subfamilies. All species are solitary, and most capture and paralyze prey, though members of the subfamily Ceropalinae are cleptoparasites of other pompilids, or ectoparasitoids of living spiders. In South America, species may be referred to colloquially as or , though these names can be generally applied to any very large stinging wasps. Furthermore, in some parts of Venezuela and Colombia, it is called , or "horse killers", while in Brazil some particular bigger and brighter