Mesothelae Spider

ryuthela sasakii, member of liphistiidae

the living members of primitive mesothelae family liphistiidae, found in southeast asia, china, , japan. of liphistiidae construct silk-lined burrows thin trapdoors, although species of genus liphistius build camouflaged silk tubes second trapdoor emergency exit. members of genus liphistius run silk tripwires outwards tunnels them detect approaching prey, while of genus heptathela not , instead rely on built-in vibration sensors. spiders of genus heptathela have no venom glands although have venom gland outlets on fang tip.

the extinct families arthrolycosidae, found in carboniferous , permian rocks, , arthromygalidae, far found in carboniferous rocks, have been classified members of mesothelae.