2. Periperatus - aka the Velvet Worm, which isn't a worm at all...it spits silk.
3. Pontic Coast - a bit chilly, but warmer than you'd think the area would be in the middle of winter.
4. Peri - they're a terrific concept, even as angels go.
6. Pell - one of many awesomely wonderful worlds created by CJ Cherryh.
7. Pas da dan, hahator - terrific phrase for a tyrannosaurid intelligence, created by Robert J. Sawyer.
8. Placodonts - armor-plated reptiles that crush molluscs with all the ease of our eating rice.
9. Pylons - without them, places like Karnak and Edfu wouldn't be half as impressive.
10. Precognition - only because of time travel (Sarah Connor Chronicles) and writing from Maia Rutledge's POV so much.