'Family Guy' -- BRIAN GRIFFIN DIES

Seems Brian Griffin won't get a shot at a 3rd novel ... 'cause the martini-swigging, chick-bangin' family dog DIED on "Family Guy" last night.

Brian -- who's been on the show for all 11 seasons -- was hit by a car in last night's episode ... and died from his injuries.

Stewie tried to save his pal by going back in time and preventing the accident -- but he had JUUUST taken apart his time machine, and was unable to rebuild it before Brian croaked.

Brian was replaced by a new dog, Vinnie -- voiced by "Sopranos" star Tony Sirico.

Unclear if Brian will somehow come back to life in future episodes -- but we wouldn't be surprised if he did.

Brian was a good dog. He was an Iraq war veteran. a porn director, coke addict, police dog and (of course) a passionate writer.

Brian was 7ish ... or 49ish in dog years.