synapsid: extinct reptile having a single pair of lateral temporal openings in the skull
reptile: any cold-blooded vertebrate of the class Reptilia including tortoises, turtles, snakes, lizards, alligators, crocodiles, and extinct forms
methylphenidate: central nervous system stimulant (trade name Ritalin) used in the treatment of narcolepsy in adults and attention deficit disorder in children