The Mesozoic period was a time of great change on Planet Earth. The climate and plant life that saw the rise of the dinosaurs looked much different than it does today. The climate was generally hotter during this period, though warming and cooling periods frequently occurred. The many environmental changes of this period caused the fall of dinosaurs and the rise of small mammals.
The word Mesozoic means, “middle life.” The period was given this name because it is the middle period of three eons of animal life on Earth, between the Paleozoic era and the Cenozoic era. The period lasted from 250 million years ago to 65 million years ago. It includes the Triassic period, the Jurassic period and the Cretaceous period. This period spawned the rise of many new life forms, as well as the impact of the asteroid that struck near the Yucatan peninsula.
Climate of the Mesozoic Period
During the Mesozoic era, the climate on Earth was very warm and dry. These were perfect conditions to support the lush plant life that was required to support many of the dinosaur species that developed during this time. The polar ice caps did not yet exist. It was not until the Jurassic period that the oceans began to rise causing flooding on the land. This flooding brought along with it humidity, which began to change the types of plants that existed on Earth. By the Cretaceous period, the climate had begun to cool again. The periods of warming and cooling had significant effects on the types and varieties of animal forms that appeared during the Mesozoic era.
Plants of the Mesozoic Period
The plants of this period were mainly coniferous, evergreen trees such as yews, pines, cypress, redwoods and cycads that had woody stems and tough leaves. Seed ferns and gingko trees flourished. All these species provided the food energy to sustain the dinosaurs. Later in the period, flowering plants began to appear during the late Cretaceous period of the Mesozoic era.
Animal of the Mesozoic Period
The Mesozoic era followed the Permian Extinction. This event caused the extinction of 95 percent of the ocean’s life forms and 70 percent of the land’s life forms. The plants that survived the Extinction were plants that possessed enclosed seed capsules. Though many fish species died during that cataclysm, those that survived were able to thrive. Amphibians, turtles and small reptiles dominated the land areas. Around the middle of the Mesozoic period, the dinosaurs emerged, growing to extraordinary sizes. Toward the end of this period, birds began to evolve. At the end of the third period of the Mesozoic era, marine animals like sharks and rays appeared. The first marsupial mammals came into existence. Carnivorous dinosaurs were more prevalent. Another mass extinction occurred to again change the face of wildlife on the planet. Scientists theorize that this was cause by large amounts of dust thrown up into the atmosphere by volcanic eruptions or an asteroid hitting the Earth.
The planet has experienced many changes over time. The study of the Mesozoic period demonstrates how profound the changes can be and how evolution adapts to the changing environmental conditions.