This is just so them, I loved it!

Jeez it's like Jurassic Park Doctor Who style.

So there's just a few things and I'm probably the only who noticed since I am in fact a paleontologist but here's a few things your should know:
First: ALWAYS capitalize a dinosaur name like Tyrannosaurus or Velociraptor. They are proper nouns.
Second: The proper way to shorten Tyrannosaurus rex is T. rex. You never capitalize the subspecies name.
Third: Pterodactyl is outdated. Always use pterosaur when speaking of the flying reptiles.
Fourth: This works for scientific names of living animals as well such as Gorilla gorilla.
Fifth: You were correct in keeping stegosaurs, and ankylosaurs lower-cased.
So now that you've had your dinosaur lesson for the day, loved the story!

Wow! Dare I say it, that that was a wild... *ahem* ride...