Poebrotherium was first named by scientist Joseph Leidy in 1848, and its relationship to other White River fossils was later expanded by him in 1853.[2] Fur trapper Samuel Culbertson was working in Nebraska in pursuit of fur bearing mammals, and found a collection of strange fossil animal bones. He sent a box of these bones to his family back east, and not knowing what to make of them, they forwarded the remains to Leidy for identification.[3] Several animals' remains were included in this package, but one of the most interesting was that of a small mammal, about the size of a small deer or sheep. In addition to a partial skull, a portion of a forelimb was found. The portions that Leidy was able to examine helped him determine it was likely related to modern llamas, even though there was a