R00K |
Yes you can. From the Bestiary 2, it is in the description of the monster:
"These dinosaurs [Compsognathus] can serve spellcasters as a familiar. A compsognathus familiar grants its master a +4 bonus on Initiative checks."
http://paizo.com/pathfinderRPG/prd/additionalMonsters/dinosaur.html#dinosau r,-compsognathus