Australopithecus is a big word that describes a group of very old monkey-like creatures that lived a very long time ago. These creatures are important because they are believed to be the ancestors of humans, which means that people like you and me might have come from these creatures!
Australopithecus creatures were around from about four to two million years ago. They lived in Africa, which is a big continent that looks like a big boot at the bottom of the world map. They were around during what's called the Early and Mid-Pleistocene Epochs, which is a fancy way of saying a long time ago when the world was different than it is today.
The Australopithecus creatures were different than monkeys that we know today because they looked a lot like people. They had long, skinny arms and legs, but they also had big, strong jaws filled with sharp teeth that they used to eat things like plants and animals. They were also much smaller than people today, standing only about 4 feet tall.
People who study Australopithecus creatures believe that they lived in groups, kind of like big families. They probably walked around on two legs, which is a big deal because it's one of the main things that makes people different than monkeys. But they were not quite as smart as people today, which is another big difference.
In summary, Australopithecus creatures were monkey-like, but also people-like creatures that lived a really long time ago in Africa. People believe that they are the ancestors of humans and played an important role in how we evolved.