The term 'Paleozoic and Others' refers to a series of geological ERAS that occurred in Earth's history. The Paleozoic Era, which began about 541 million years ago and ended about 252 million years ago, was the first of three major ERAS in the Phanerozoic Eon. It was followed by the Mesozoic Era and then the Cenozoic Era. During the Paleozoic Era, many of the major groups of animals and plants that are still alive today evolved, including fish, amphibians, reptiles, and mammals. The other ERAS mentioned in the crossword solution, such as the Mesozoic and Cenozoic ERAS, are also important periods in Earth's history, during which many species evolved and diversified.