Okay kiddo, imagine that a very long time ago, there were some animals that looked almost like us humans. One of these animals is called Paranthropus boisei, but let's just call it "Boisei" for short. Boisei was a kind of hominid, which is like a distant cousin to us humans.
Boisei had a really big and strong jaw with lots of powerful teeth, which meant that it could eat tough and hard foods like nuts, seeds, and even roots. This is because during that time, there weren't as many soft and yummy foods available like we have today.
Boisei was also pretty short, standing only about 4 feet tall, but it had a really big brain for its size! This meant that Boisei was pretty smart and could do things like make simple tools and communicate with other Boisei.
But, unfortunately, Boisei didn't survive for very long and all of them eventually went extinct. Scientists aren't exactly sure why this happened, but some think it's because they weren't able to adapt to the changing environment around them.
So, even though we humans didn't directly evolve from Boisei, they were still a really interesting and important part of our family tree.