Archaeopteryx does have a wee-little hyperextendable killing claw, too, shown especially in the Thermopolis specimen. This is interesting because it may mean that the killing claws first appeared when these dinosaurs were small, and were not used to bring down/cut open large prey (that was a later use when the deinonychosaurs got larger).

(I just realized that I have these notions in my head with no clear understanding as to how they’ve got there. To paraphrase Robertson Davies, “I am, of course, a self-educated man.” “But your education is a mess!” “Ah, but it’s a rich, fruity mess.”)