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 Silurian period (443-416 million years ago) was the shortest period of the Paleozoic Era. This is when the very first terrestrial plants and invertebrates (i.e., bugs) appeared, while the most important development in vertebrate life was the evolution of jawed fish.