As far as I can tell from the photos, it is just a lump of limestone; an irregular shape with some exfoliar weathering (causing what you might be taking as a shell or crust).
Dino bones are often black, and (like most bones) can be recognized by their cellular structure, though that's seen best in cross-section or on worn-down surfaces. Also, I'm pretty sure I can see shell fragments in it.
The rocks of Wharfedale are Carboniferous in age. The dinosaurs did not appear until the Triassic - at least 50 million years later. You have to go east to Bedale (for instance) before you come into Triassic terrain.