Medical Definition of ARTHRODESIS. : the surgical immobilization of a joint so that the bones grow solidly together: artificial ankylosis. the surgical immobilization of a joint so that the bones grow solidly together. ADVERTISEMENT.
Trapdoor spiders are not particularly harmful to man however, like Tarantulas, the tiny hairs on the legs of some species leave tiny red marks where the toothed hairs on the spiders' feet have clung to the skin. Mouse spiders are also a type of Trapdoor spider with huge chelicerae and may measure up to 35mm in body length.
Two prime candidates for the most dangerously venomous spiders to people are the âBrazilian wandering spiderâ (Phoneutria spp.) and the âSydney funnelweb spiderâ (Atrax robustus). The âBrazilian wandering spider,â from Central and South America, can be very defensive when threatened.