| Answer | Crossword Clue |
|---|---|
| TRIASSIC | Period bookended by extinction events |
| PERMIAN | Period marked by the largest mass extinction in earth's history |
| Answer | Crossword Clue |
|---|---|
| TRIASSIC | Period bookended by extinction events |
| PERMIAN | Period marked by the largest mass extinction in earth's history |
Crossword
a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.