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,
Coastal peacock spider this display. Coastal peacock spider Maratus speciosus, sometimes called the coastal peacock spider, is an Australian species of jumping spider (family Salticidae). They are only known to inhabit the vegetation of the coastal sand dunes of southwestern Western Australia. Like other "Maratus" spiders, the males of the species engage in a courtship display during which they raise their third pair of legs and their abdomen, presenting their colorful opisthosomal plate to potential female partners. Unlike other "Maratus", however, the males of this species have a set of bright orange hairs (setae) along both edges of the opisthosoma which only become