Glossopteris Browniana leaf fossil 
11 x 6 inches
Permian age
265 million years old
Illawarra coal measures
Dunedoo, NSW 
 
This Paleozoic plant fossil from Australia, known as Glossopteris browniana because because of its tongue-shaped leaves is the largest genus of the extinct order of seed ferns known as Glossopteridales. The Pteridospermatophyta, also called seed ferns, is an extinct gymnosperm division of the Plantae kingdom. Members of this division were predominant at the late Devonian and met extinction at the end of the Triassic period.
The Glossopterids are significant to geological history as their fossils provided the first evidence of continental drift. The predominance of glossopterid leaves in Pennsylvanian to Triassic rocks of Australia, Africa, South America, Antarctica, and the Indian peninsula lead geologists to conclude that these continents had once formed Gondwanaland. Moreover, the plants producing these leaves were ecosystem dominants in the Southern Hemisphere for most of this period, particularly during the Late Permian.