"Bringing Up Baby" (1938) Katharine Hepburn, Cary Grant

From right smack in the Golden Age of Hollywood, "Bringing Up Baby" follows the romantic misadventures of would-be groom David Huxley (Cary Grant) as a disgruntled university paleontologist trying to recover the missing "intercostal clavicle" of a dinosaur for his exhibit in a natural history museum. Professor Huxley is also about to marry another dedicated scientist who is also, alas, the most career-oriented and asexual woman on the American Eastern Seaboard.

Who should come along to complicate his life but Susan Vance (Katharine Hepburn), a ditsy and love-hungry socialite with enough Life Force to power the Manhattan skyline.
Miss Vance proceeds to try and win David over after they have a strange series of chance meetings and predicaments that somehow convinces her that he's in love with her. Typical man, he doesn't realize it. It takes a bit of pursuit on her part to get him to comprehend his true feelings. But first, of course, David must endure many awkward social situations and near mental-breakdown before he, too, comes to see the possibilities in hitching his star to someone the polar opposite of his own nebbish personality.

Here is just one of those situations. Susan's dog has "stolen" the dinosaur bone and to get it David must follow the canine and his mistress to her aunt's country house. Did I mention that the aunt is also a rich benefactor of the university David works for? Things get dicey fast.

One of the funniest of the "screwball comedy" sub genre of American films, it was also a disappointment at the box office of the time. Perhaps there were just too many romantic comedies out there.

In any case, Cary Grant went on to bigger films like the great action film ,"Gunga Din" and "His Girl Friday" with Rosalind Russell (the latter directed by Howard Hawks, the fellow in charge behind the camera here).
Ms. Hepburn, however, had to wait another two years to get out of her slump at the box office. Her success in MGM's "The Philadelphia Story" (also with Grant, and co-starring James Stewart) gave her a new lease on stardom and one she never relinquished hereafter.

From Wikipedia:
"Bringing Up Baby"
Director: Howard Hawks

Katharine Hepburn ... Susan Vance, a ditzy but well-meaning socialite
Cary Grant ... Dr. David Huxley (alias Mr. Bone), a mild-mannered paleontologist
Charles Ruggles (credited as Charlie Ruggles) ... Maj. Horace Applegate,
Walter Catlett ... Constable Slocum, who arrests most of the cast
Barry Fitzgerald ... Aloysius Gogarty, a heavily stereotyped Irish-American gardener
May Robson ... Aunt Elizabeth Random, Susan's snobbish aunt
Fritz Feld ... Dr. Fritz Lehman
Leona Roberts ... Mrs. Hannah Gogarty, wife of Aloysius
George Irving ... Dr. Alexander Peabody, Mrs Random's lawyer
Tala Birell ... Mrs. Lehman
Virginia Walker ... Alice Swallow, David's shrewish fiancée
John Kelly ... Elmer
Asta ... George, a dog
Nissa ... both of the leopards
Ward Bond ... Motorcycle cop at jail (uncredited)
Jack Carson ... Circus Roustabout (uncredited)