The National SAFEKIDS Campaign recommends that no child under the age of 12 be left at home alone. However, consider a child's age and maturity level. For example, if a child is extremely impulsive, it might be best to wait until he or she is older than 12.
Did people and dinosaurs live at the same time? No! After the dinosaurs died out, nearly 65 million years passed before people appeared on Earth. However, small mammals (including shrew-sized primates) were alive at the time of the dinosaurs.
Geological timescale. Triassic period: 250â200 million years ago. Jurassic period: 200â145 million years ago. Cretaceous period: 145â65 million years ago. Dinosaurs roamed the planet for about 165 million years, during a time in the Earthâs history called the Mesozoic Era. It is difficult to imagine how long this was, until we compare it with ourselves: humans have lived on Earth for less than two million years. During the Mesozoic Era, the Earthâs landmasses changed dramatically, new seas were formed, and plants and animals evolved.