During the Mesozoic period Greece was the sea bed of an extended ocean, therefore fossils of Dinosaurs have not been found in our country, while a multitude of remains of sea organisms still exist in its mountain ranges. During the period of the Alpic formation Greece started to emerge from the water and thirteen -fourteen million years ago this land was inhabited by various peculiar and wild animals like the Choirolophodon the Chios, a cousin of the known elephant, and others. Later, other animals appear many of which were later wiped out by man himself. The vegetation of Greece was also very rich during the prehistoric age. The knowledge of vegetation and animal species of our country is the necessary prerequisite for the study of man in the relevant period.