The Middle Miocene Flora of the Chalk Mountain Formation, Warrumbungle Volcano Complex, NSW, Australia

Abstract

A Miocene flora from the Chalk Mountain Formation occurring on a spur of the Warrumbungle Volcano Complex to the north-west of Coonabarabran, near Bugaldie is described. The flora consists of representatives in the families Equisetaceae (Equisetum sp. indet.), Isoetaceae and Araucariaceae ( Agathis sp.). Among the angiosperm families are Cunoniaceae (Ceratopetalum priscum), Moraceae, Myrtaceae (Eucalyptus bugaldiensis), Urticaceae (Dendrocnide sp. A aff. D. excelsa). This paper describes the first fossil record of Dendrocnide (Urticaceae) leaves from Australia and the second post-Cretaceous record of the genus Equisetum, the first from the Miocene. The flora includes rainforest, swamp and sclerophyll plant forms and indicates a warming and drying climate as the Australian plate moved northwards during the Middle Miocene.