The Jurassic period was the second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 millions years ago, following the Triassic Period and preceding the Cretaceous Period. During the Jurassic Period, the supercontinent Pangaea split apart. Laurentia, the northern half, made up what would eventually form North America and Eurasia. The creation of these opened basins for the central Atlantic and the Gulf of Mexico. The southern half, Gondwana, drifted into an eastern segment that now forms Antarctica, Madagascar, India, and Australia, and a western portion that forms the present Africa and South America. This rifting, along with generally warmer global temperatures, allowed for ...view middle of the document...
A new method of plant reproduction evolved during the Jurassic. Gymnosperms, cone-bearing plants such as conifers, allowed for wind distribution of pollen. This bisexual reproduction allowed for greater genetic combination and by the end of the Jurassic, the gymnosperms were widespread. The gymnosperms were first seen in the Paleozoic era and were dividd in to cycads and cycadeoids, conifers, and gingkoes. Plants such as ferns and gingkoes were the dominant plants of the early Jurassic; these plants were complete with roots and vascular tissue to move water and nutrients and a spore system of reproduction. Also palm tree-like cycads were abundant, as were conifers such as araucaria and pines. Cycads are physically recognized by the presence of a thick and wooded trunk and a crown of stiff evergreen leaves; they are also seeded plants. Both male and females of this species are known to have a long life span. These plants thrived during the Jurassic period because they prefer to be in tropical or subtropical climates. Cycads make for very hardy trees and are apparent in multiple types of habitat including deserts, swampy bogs, shaded areas, sunny areas, salt rich areas and even on rocky surfaces. These plants prevailed because of their diversity and ability to grow in any number of habitats. A significant number of herbivorous dinosaurs fed on cycads because of their hardy nature, their bountiful presence, and the fact that they grow both close to the ground and high from the ground. Like cycads, conifers are cone bearing. Most of the conifer species are woody trees such as Douglas-firs, cypresses, junipers, and firs, while only a few are recognized as plants. Currently, conifers are extremely bountiful; however, this was not the case back in the Jurassic period. Ginkgophytes or simply ginkgo is known as a genus of plant that does not flower. The Jurassic period was particularly beneficial era for the ginkgo because it allowed these plants to not only begin but to diversify. This diversification carried on through the beginning of the Cretaceous period.
Many people question how the world can truly know anything about plant species that lived so very long ago, especially since plant life does not have any skeletal remains. Fossils are any evidence of past life, this evidence does not have to contain skeletal remains and as such plants can be fossilized as well. Not all plants underwent the preservation that fossilized elements did, but some where able to be exposed under just the right conditions which enabled them to be preserved in some type of element. Fossils of Jurassic period plants can confirm the many doubts that people have. Also because so hardy were a number of the plants that began life...
