I decided to comment because of the recent article saying that authors liked their readers to comment.  This one of my very favorite writings in the legendarium anywhere, including those by the Tolkiens.  I did not see any sensitivity, spelling, grammar, or mechanics issues, although I am not very good at looking closely.  If by mechanics you mean the structure of the story, it seems really nice - episodic, each episode feeling relevant (although I don't necessarily know why) starting with the dinosaurs and ending with what for me feels like the center of the story.