Solution: When fur first came into fashion - NYT Crossword

The first and last Across entries enclose this puzzle beautifully. 1A, “When fur first came into fashion?,” had me thinking back to the Roaring Twenties at first, because of “fashion.” The entry recalls a much earlier starting point: the Cenozoic Era, which began over 65 million years ago and is known as the AGE OF MAMMALS. It turns out that 52A, “Live ostentatiously,” is the more modern reference point: It’s PUT ON THE RITZ. Irving Berlin ensconced this expression in the lexicon with a song that came along just after the 1929 stock market crash. Did you think of Fred Astaire, Young Frankenstein or Taco? Clark Gable did it, too.