Cycas revoluta
Sago Palm
CopyrightStone Museum of Geology

This specimen of the family Cycadaceae and known as the "Sago Palm" is one of a range of plants that originated in the Permian Period (290-248 mya). They became one of the most important plants of the Mesozoic until they were replaced by angiosperms (flowering plants) during the Cretaceous. Cycad reproduction is primitive with the pollen grains containing motile spermatozoa. Today, these plants are found in the wild only in South Africa and Australasia. They generally grow a single ring of 5-6 new leaf stems each summer. The oldest leaves die and fall off, leaving characteristics leaf scars on the plant's caudex (trunk).

The picture below shows a fossil cycad of the species Zamites feneonis. This specimen is from Orbagnoux, near Ain, France and dates from the Kimmeridgian of the Jurassic.

CopyrightStone Museum of Geology