Congratulations on your Pseudopod debut, Nathan!! That's awesome. Now if you can crack Escape Pod you will have the Unholy Trifecta.
Most of the story I liked very much. The child's point of view seemed very authentic, reminded me of being a kid myself (which many supposed child POVs do not evoke). I liked the developing friendship between the boy with the T-Rex phobia and the girl with the octopus phobia. I expected the T-Rex to eat the bully, so there's some extra points for subverting expectations.
What I didn't care for as much:
-Patrick's rant about dinosaurs being everywhere, but hiding as fossil fuels and recycled organic matter seemed to fall out of the kid's point of view. It seemed to be there to foreshadow the ending, where Patrick becomes the T-Rex, but it seemed that the author's voice took over the kid's story to provide this foreshadowing.
-I'm not sure if I'm reading the ending right, but the way I read it, the dinosaur is entirely imaginary. Because, in Patrick's mind, the T-Rex has bowed down to him, he feels that he is more worthy than the tyrant king himself and will now become the dominant one. However, I didn't think he actually changed to a sharp-toothed monster, he just became another bully like his tormentor. That tyrant bully will be replaced by Patrick, and this is a tale of a rise of a bully. There's nothing wrong with that, but it's hard to compare with actual dinosaurs, and I have trouble having much compassion for Patrick when I think about what it seems he is choosing to become.