Theropod-eating spiders

[StephanPickering@cs.com]

       Throughout South America and Australia, in particular, are enormous, theropod-eating, "trap-door" arachnids of the family Theraphosidae Thorell 1870, in particular Avicularia avicularia (Linnaeus 1758), Theraphosa blondi (Latreille 1804), Selanocosmia crassipes (L. Koch 1874), and Xenesthis immensis (Ausserer 1875). My question is: has anyone done extensive work on these taxa's ecologies relative to the dinosaurs they eat?
       Another spider -- whose name eludes me -- is, as I recall, in the Amazon, as big as platter, hanging in tree limbs, its web almost like a fisherman's net, ensnaring bats and theropods. Any data on this taxon, as well, will be appreciated.
       Arachnids play an important role, along with ants, in the ecosystems extant forest/jungle theropods inhabit. Has there been anyone who has worked out the systematics of pre-K/T spiders? Sizes?