FOSSIL PLANTS/Gymnosperms 451 Figure 12 Thick, robust leaves of the extinct conifer Pagiophyl lum peregrynum (Upper Jurassic, Lyme Regis, Dorset, England) Foliage of this type could belong to several families of conifers including Araucariaceae and Cheirolepidiaceae Figure 14 Tongue shaped leaves of Glossopteris are character istic of the Permian and Triassic rocks of Gondwana: G browniana (Permian, Nagpur, India) the same species or individuals Some are known to have been large trees The leaves of Glossopteridales are highly characteristic They are large and tongueshaped with a conspicuous midrib and a network of veins (Figure 14) Pollen organs and ovules were borne on special branches on the upper surfaces of some leaves Some fructifications are foliar, whereas others are thought to resemble cones Czekanowskiales (Jurassic to Cretaceous) This is an extinct and poorly understood group The leaves of Czekanowskiales are distinctive They are highly dissected, in some species almost like a bundle of fibres Ovules are thought to have been borne in cones composed of capsulate appendages The habit of the plant remains poorly understood Ginkgoales (? Permian to Recent) Figure 13 Foliage of the Dawn Redwood Metasequoia was documented in the fossil record long before living specimens of these large conifers were discovered in the Chinese province of Szechuan in 1944 (Eocene, Driftwood Canyon, Smithers, British Columbia, Canada) This group contains one living species Ginkgo biloba, which is a large tree that bears distinctive fan-shaped leaves Pollen organs are loose catkin-like cones, whereas ovules are in pairs on stalks They are borne on short leafy shoots on separate plants The natural distribution of modern Ginkgo is restricted to a small area of China, but leaves of Ginkgo type are