| Answer | Crossword Clue |
|---|---|
| SIXTYDAY | Like some billing periods |
| PEAK | Like some airline travel periods |
| protoavis | a member of the genus Protoavis of the Triassic periods, with dinosaur-like tail and hind legs, but some anatomical features characteristic of modern birds |
| protoavises | PROTOAVIS, a member of the genus Protoavis of the Triassic periods, with dinosaur-like tail and hind legs, but some anatomical features characteristic of modern birds |
| STAR | Some billing |
| HOUR | Billing unit, for some |
