The letters following each Review Question refer to the corresponding Learning Objective from the Chapter Opener. What was the Earth's land surface like during the early Paleozoic? (E)

The Paleozoic Era spans from approximately 542 to 250 million years ago. It is divided into six distinct geological periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The early Paleozoic refers to the Cambrian, Ordovician, and Silurian periods.

During the Cambrian period, the Earth's land area was mostly limited to a single supercontinent, named Gondwana. Gondwana consisted of present-day Africa, South America, Antarctica, India, and Australia. The overall landscape was prevalently barren, as terrestrial plants had not yet evolved. The climate during this time was warm and tropical, with no polar ice caps.

In the Ordovician period, the Gondwana supercontinent still dominated the land surface, but it started drifting towards the South Pole. Around the end of the Ordovician, the first primitive plants started to appear on the surface. The glaciations occurred during this period, resulting in a widespread ice age, with much of Gondwana covered by ice caps.

During the Silurian period, Gondwana shifted further towards the southern hemisphere. Many of the Earth's other landmasses started to approach one another, eventually forming the supercontinent named Laurussia or Euramerica. The Silurian period witnessed an increase in the variety of land vegetation with the beginning of simple vascular plants that could transport water and nutrients throughout their tissues. The climate became warmer and tropical, with a relatively shallow ocean covering large parts of the continental crust. To sum up, the early Paleozoic Earth's surface was primarily made up of the supercontinent Gondwana, shifting towards the South Pole. The landscape was mostly barren in the beginning, and simple terrestrial plants began to evolve by the end of the Silurian period. Climate changes associated with continental drifts influenced the distribution of ice caps and the overall temperature of the environment.