Fossil Sphenopteris from Foxley, Tollcross.
Sphenopteris were seed bearing ferns dating from the Carboniferous Period (also known as the Coal Age) which lasted from 360-290 million years ago. As the name implies, they used seeds to reproduce, and were amongst the earliest seed bearing plants on the planet. Seed ferns are now extinct. True ferns, a group which have survived from the Carboniferous Period, reproduce by means of minute spores which are usually situated on the under sides of the leaves.
Reproduced with the permission of Glasgow City Council, Glasgow Museums
Carboniferous Period, fossils, geology, seed ferns, Sphenopteris