The Earliest Fossils assignable to Taxaceae exhibit foliage and reproductive structures almost identical with those of extant forms. It is impossible to trace the origins of this group. The Paleotaxus had its first appearance in the Lower Jurassic. It has linear needles twisted near the base, and they lie in a single plane. Vegetative and ovulate parts have also been discovered.
Tomharrisia is from the Cretaceous. It has horizontally spreading vegetative shoots with two-ranked leaves. It has also been found in the Jurassic and has hypostomatic leaves with monocyclic stomata surrounded by 4-6 papillae. Poteridion is from the Jurassic and has a terminal ovule that is slightly enclosed by the scale leaves.
Vesquia is from the Cretaceous and the fossil seed is closely related to the Torreya. The megaspore membrane is smooth unlike the granulose texture present in most gymnosperms.
Amentotaxus is from the Tertiary. This genus was a common element in many mesophytic forests in the Tertiary. Fossil remains have been described in Europe and western Africa as well as east Asia. Vascular supply to the integement is completely lacking. The seed is borne at the tip of a penduncle. Amentotaxus is sometimes placed in the Cephalotaxaceae.
Hartzell, H. The Yew Trees: Biography of a Species. Hulogosi Publishers: Eugene, Oregon, 1991.
Sporne, K.R. The Morphology of Gymnosperms-The structure and evolution of primitive seed plants. Hutchinson University Library: London,1965.
Taylor, Edith and Thoomas N. The Biology and Evolution of Fossil Plants. Prentice Hall: Englewood Cliffs, NJ,1993.
