The Lovely of February The Cenozoic Era: The Quaternary and Tertiary

The Cenozoic includes the period that began roughly 65 million years ago to the present. Historically, the Era has been divided into two periods: the Tertiary and the Quaternary. These terms came from the 19th century when rock formation in Europe was classified as primary (being the oldest), secondary and tertiary, with quaternary being coined slightly later. As more sophisticated geologic understanding evolved, primary and secondary were dropped from use. Only Tertiary and Quaternary remained as the divisions of the era.