Where are trilobites found?
Trilobites were most abundant during the Cambrian Period (545 to 490 mya), but after the middle Devonian (about 370 mya) they were in decline and they finally became extinct at the end of the Permian (251 mya). In Victoria, trilobites occur in Cambrian rocks in the Heathcote district and in Gippsland, and in early Ordovician rocks (about 489 my old) at Waratah Bay. However, they are most widespread in late Silurian to early Devonian (420-400 my old) siltstones and sandstones in the Heathcote, Kilmore, Lilydale and Kinglake districts.
