There are many parts of the railway business which are interesting in their own right and which questions are asked about from time to time. This page looks at detailed parts of equipment, systems, standards, dimensions, procedures and infrastructure in no particular order. New items will be added from time to time.
The Ediacaran Period ( /iËdiËÃ¦kÉrÉn/), spans 94 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 541 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia.
The Devonian Period is a part of the Paleozoic Era, which covers  the time from 541 to 252.17 million years ago. It began with the  Cambrian explosion, in which most phyla oâ¦f life began, and ended  with the mass extinction called the Permian-Triassic extinction  event.