ASBOG Practice Exam 2025 - Free Practice Questions and Study Guide for the National Geology Exam.

The correct answer is based on the classification of geological time periods within the Paleozoic era. This era spans from approximately 541 to 252 million years ago and is characterized by a succession of distinct geological periods that showcase the evolution of life on Earth.

The sequence of periods within the Paleozoic era begins with the Cambrian, followed by the Ordovician, then the Silurian, and finally the Devonian. These periods were marked by significant geological and biological developments, including the proliferation of marine life during the Cambrian, the diversification of life forms in the Ordovician, the emergence of fish in the Silurian, and the colonization of land by plants and animals in the Devonian.

Other choices include periods or eras that do not belong to the Paleozoic or are incorrectly ordered chronologically. For example, the Carboniferous and Permian periods are indeed part of the Paleozoic era, but they come after the Devonian period. The Mesozoic and Cenozoic are later geological eras entirely, and the Hadean, Archean, Proterozoic, and Phanerozoic refer to different eons and eras that span broader time frames than the specified periods of the