Simplify the following text for a Grade 10 native English-speaking person.
Original: The Ediacaran Period represents the time from the end of global Marinoan glaciation to the first appearance worldwide of certain trace fossils ( Trichophycus pedum ) at the base of the Cambrian .
Simplified: The Ediacaran Period ( ca . 635-542 Mya ) represents the time from the end of global Marinoan glaciation to the first appearance worldwide of somewhat complicated trace fossils ( Treptichnus pedum ) .