Simplify the following text for a Grade 7 native English-speaking person.
Original: The first fossils named Edmontosaurus were discovered in southern Alberta , Canada , in what used to be called the lower Edmonton Formation . The type species , E. regalis , was named by Lawrence Lambe in 1917 , although several other species that are now classified in Edmontosaurus were named earlier .
Simplified: Edmontosaurus was named by Lawrence M. Lambe in 1917 from a fossil found in Edmonton Rock Formation , in Alberta , Canada .