Okay kiddo, so poebrotherium is a word that means a type of animal that lived a long time ago. It's kinda like a cousin of horses and deer.
So imagine a really big field full of grass and bushes, and there's this animal walking around with four legs and a long nose. It's about the size of a big dog or a small horse and it has fur all over its body to keep it warm.
Poebrotheriums used to live in places where it was cold and snowy, like in parts of North America. They would eat things like grass, leaves, and possibly even twigs and bark from trees.
Scientists have found fossils, which are like bones from these animals, and they've studied them to learn more about what they looked like and how they lived.
So that's basically what poebrotherium is, a furry little guy that lived a long time ago and was related to horses and deer.