Almost all organisms alive today evolved from marine creatures alive at the beginning of the:

Question

Quizplus · Accepted Answer

The Paleozoic era is known as the "age of invertebrates" and saw the evolution of many aquatic organisms such as fish, crustaceans, and mollusks. It was during this era that the first land plants and animals also appeared. Therefore, it is the best choice for the statement that almost all organisms alive today evolved from marine creatures alive at the beginning. The Cenozoic era and Jurassic period were too recent for such a broad statement, and the Precambrian time is too far back in history for such evolution to have occurred.

Almost All Organisms Alive Today Evolved from Marine Creatures Alive