Theory of Plate Tectonics was established by Alfred Wegener. Fossils and Mountain ranges were his evidences.
Alfred Wegener created the idea of continental drift and wrote 'The Origin of Continents and Oceans' to support his idea. His theory was rejected by geologists at first. His ideas have been scientifically proven as time goes on.
Wegener gave examples in both plant and animal fossils, mountain ranges to support his idea.
Appalachian Mountains are situated from West to East in North America and be interrupted at New Foundland in the East coast of North America. Another mountain range starts in Greenland and go along in Ireland, UK and Norway with the similar stratification.
Fossils are the stongest evidences of plate tectonics. Same plant fossils can be seen in distant continents such as South America and Africa. One can say that it is because of the birds and wind. They might be carried seeds across oceans. It maybe a logical objection to Wegener's theory but could giant dinosaurs swim entire the ocean? They obviously could not. Fossil of the same dinosaur can be seen in South America, Africa, India and Antartica. Only reasonable explanation of that is once all this continents were together. This continent is called Gondwana. These evidences are some of strong evidences of plate tectonics.