Parentheses and brackets ( ) [ ] Round Brackets Round brackets (also called parentheses, especially in American English) are mainly used to separate off information that isnât essential to the meaning of the rest of the sentence. If you removed the bracketed material the sentence would still make perfectly good sense.
Most of the facts about the Velociraptor are now well known. This is due to the discovery of several fossils. It lived during the Cretaceous period and became extinct 70 to 80 million years ago. Like the other dinosaurs it likely perished when a comet / asteroid struck the Earth at the time.
Dinosaurs lived between 230 and 65 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans, Homo sapiens, appeared. Scientists divide the Mesozoic Era into three periods: the Triassic, Jurassic and Cretaceous. During this time, the land gradually split up from one huge continent into smaller ones. The associated changes in the climate and vegetation affected how dinosaurs evolved.