There are but three kinds of spider in the world:
fancy, modern ones, which includes all the really good web-builders
tarantula ones, which includes all the big hairies
and Mesotheles, an ancient race of spider-kin who maintain the lost ways of their ancestors into this, the modern age.
Mesothele spiders are now represented by less than 100 species, all found in southeast Asia.
Their most obvious tribute to the elders is a row of peculiar armour plates that adorn their abdomen, but don't quite cover it.
They use trapdoors and tripwires to ambush prey and for a long time it was thought they were non-venomous. It wasn't until 2010 that scientists finally found the tiny venom ducts in their fangs and similarly undersized venom glands.
Mesotheles don't bother with venom so powerful it can fell a cow or elegant webs covered in the latest adhesive chemistry. They just jump ya.