Conifer Challenge

Conifers are a division of vascular land plants containing a single extant class, Pinopsida. They are gymnosperms, cone-bearing seed plants. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, but also in similar cool climates in mountains further South. Conifers are of great economic importance for coniferous sawnwood and paper products. The earliest conifers in the fossil record were in the late Carboniferous Pennsylvanian period about 300 million years ago. An important adaptation of these gymnosperms allows plants to live not so dependent on water. Other adaptations are pollen, so that fertilization can occur without water and seeds, allowing the embryo to be transported and developed elsewhere. Conifers appear to be one of the taxa that have benefited from the Permian–Triassic extinction, and were the dominant land plants of the Mesozoic era. They were disrupted because of the flowering plants that first appeared in the Cretaceous, and became dominant in the Cenozoic era. Conifers were the main food of herbivorous dinosaurs, and their resins and poisons would give protection from herbivores. Reproductive features of modern conifers evolved by the end of the Mesozoic era.