Abstract
Increasing fossil studies in recent years reveal the change in woody plant diversity from past to present and offer the opportunity to compare with today. The aim of the study is to examine the temporal and spatial distribution of gymnosperm genera and species identified in fossil wood studies in Türkiye. The oldest of the gymnosperm fossil woods identified in our country are from the Middle Jurassic period, and two of the three genera are Xenoxylon and Protelicoxylon, which have no representatives today, and Agathoxylon fossil genus, one of which has representatives in the Southern Hemisphere today. These three fossil genera also indicate the existence of a terrestrial coastline on the Erzurum-Gümüşhane line during the middle Jurassic period. The most common gymnosperms belong to the Oligo-Miocene period, and these are the fossil genera Pinuxylon, Cedrus, Taxodioxylon, Glyptostroboxylon, Cupressinoxylon, Ginkgoxylon, Juniperoxylon, and Podocarpoxylon. While some of these genera (Pinus, Cedrus, Cupressus, Juniperus) have representatives today, the representatives of others (Glyptosrobus, Taxodium/Sequoia, Ginkgo, and Podocarpus) have moved away from Türkiye.