Interesting. Here's
another article.
Among the finds were some proboscideans, including some early gomphotheres about the size of a domestic bovine (not much bigger than
Moeritherium), and some deinotheres.
Gomphotherium had both upper-jaw and lower-jaw tusks, and
Deinotherium had downward-pointing lower tusks(!).
Interestingly,
Moeritherium itself had enlarged second incisors -- the beginnings of tusks.
And as to
Deinotherium, a reasonable intermediate is forward-pointing lower tusks; has any such intermediate been found?
An odder beast found there is
Arsinoitherium, which looks like a rhinoceros with two side-by-side front horns. Judging from Africa's isolation during the earlier part of the Cenozoic,
Arsinoitherium would have to be an afrotherian, but beyond that it's difficult to work out what its closest relatives were.
Arsinoitherium seems like a case of convergence on rhinoceros-like form;
Uintatherium and
Titanotherium also converged onto that form, meaning that rhinoishness had been invented at least four times.