Complex sentence: Ron Dawson's children's story "Scary Bones meets the Dinosaurs of the Jurassic Coast" creates a myth of how Durdle Door came to be, whereby an as yet undiscovered dinosaur called "Durdle Doorus" which is magically transformed into Durdle Door.
Split into simpler sentences: Ron Dawson's children's story "Scary Bones meets the Dinosaurs of the Jurassic Coast" creates a myth of how Durdle Door came to be. The protagonists meet an as yet undiscovered dinosaur called "Durdle Doorus" which is magically transformed into Durdle Door.