| Answer | Crossword Clue |
|---|---|
| permian | relating to the last period of the Palaeozoic era |
| devonian | relating to a type of rock formed in the fourth period of the Palaeozoic era |
| jurassic | relating to the second period of the Mesozoic era |
| triassic | relating to the first period of the Mesozoic era |
| carboniferous | Of, relating to, or denoting the fifth period of the Paleozoic era, between the Devonian and Permian periods |
| triassic | Of, relating to, or denoting the earliest period of the Mesozoic era, between the Permian and Jurassic periods |
| quaternary | Of, relating to, or denoting the most recent period in the Cenozoic era, following the Tertiary period and comprising the Pleistocene and Holocene epochs (and thus including the present) |
