A plesiosaur can be seen swimming in the pool in the last shot of the library floor. In a later episode of the follow-on series, Jenkins mentions that the largest animal they have in the library is Nessie, a.k.a. the Loch Ness Monster. Nessie believers have speculated that the monster might actually be a plesiosaur.
Mentioned by Stana Katic's character is a pirate's "puffy shirt." This may be a reference to the Seinfeld episode (Season 5, Episode 2) in which Jerry unknowingly agrees to wear a puffy shirt on television.