You searched for: “palaeozoic
Paleozoic, Palaeozoic (adjective), more Paleozoic, most Paleozoic
Relating to the geologic era extending from the end of the Precambrian to the beginning of the Mesozoic: The Paleozoic period, formally termed "Primary", dates from about 542 to 250 million years ago, from the era of trilobites to those of the reptiles.