We have a large variety of spiders archived from small jumping spiders to large tarantulas in amber. Apart from solitary spiders in amber we have numerous pieces of amber that contain spiders in various interactions with other insects and animals.
Spider vs Lizard in Burmite
A small but well preserved and well postured lizard and harvestman spider in amber.
Most arachnids lack extensor muscles in the distal joints of their appendages. Spiders and whipscorpions extend their limbs hydraulically using the pressure of their hemolymph. Solifuges and some harvestmen extend their knees by the use of highly elastic thickenings in the joint cuticle. Scorpions, pseudoscorpions and some harvestmen have evolved muscles that extend two leg joints (the femur-patella and patella-tibia joints) at once. The equivalent joints of the pedipalps of scorpions though, are extended by elastic recoil.