Timeline of Life The Timeline of Life is one of the first Great Lessons in a Montessori classroom. It is also referred to as the Coming of Life. ETC Montessori is known for creating some of the most beautiful timelines for Montessori classrooms, with the Timeline of Life being the most accurate and concise timeline available. We are now offering this timeline with a full interactive experience. Tap on the METIS logo and discover movies, research questions and beautiful pictures that complement the subjects and ideas presented. Now students can spot the Devonian explosion of plant life. Each lineage line is clearly marked along with detailed images that beautifully illustrate the originating events which lead to various evolutionary patterns such as the development of mammals. This timeline is the most up-to-date edition, and will always be up to date as an e-book.