This chapter details the geography and ecology of the Mesozoic period. It explains that the Mesozoic period was a time of major diversification and radiation, leading to large-scale changes in flora and fauna by the end of the era. In Mesozoic oceans, neoselachians diversified, while the total diversity of tetrapods changed relatively slowly. Meanwhile, lissamphibians evolved and the two major lineages of amniotes diversified into Synapsida and Sauropsida. The chapter highlights how the era's history of extinction events opened the way for a new faunal balance in the Cenozoic period. Most Mesozoic extinction events resulted from intense episodes of volcanic activity accompanying collisions and splitting of continents as Pangaea formed and later ruptured.
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Geography and Ecology of the Mesozoic
Chapter
Geography and Ecology of the Cenozoic
This chapter explores the geography and ecology of the Cenozoic era. It cites how changes in continental positions have affected Earth's climates and the ability of vertebrates to disperse between its regions. By the late Mesozoic era, continental separation and epicontinental seas had isolated populations of terrestrial tetrapods and freshwater vertebrates, which limited possibilities for their migration between continents. While the best-known Cenozoic extinction took place at the end of the Pleistocene era, and this mainly affected only larger land animals. The chapter also considers debates on whether Pleistocene extinctions were mainly caused by climate changes or the spread of humans across the globe.
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Glaciation and Biogeographic Dynamics of the Pleistocene
This chapter discusses the glaciation and biogeographic dynamics of the Pleistocene. It highlights that the climatic upheavals of the Pleistocene caused major shifts in the geography of life across the planet. Earth experienced numerous glacial-interglacial cycles during the Pleistocene, so the cycle of glacial and interglacial periods affected the entire planet not just those specific regions covered by glaciers. The chapter looks into the biogeographic responses to climatic cycles of the Pleistocene. It also explains what Pleistocene refugia are. These are the areas to which species were displaced during glacial episodes. Finally, the chapter looks at extinctions of the Pleistocene megafauna.
