After years of being mislabeled as Heros severus, the mouthbrooding severums have now been reclassified as Heros liberifer. Per Cichlid Room Companion:
A new Heros species has been described
By Juan Miguel Artigas Azas
A new Heros species for what in recent years has been incorrectly known as Heros severus has been described by Wolfgang Staeck and Ingo Schindler in the journal “Bulletin of Fish Biology”. The new species Heros liberifer differs from all Heros species by a pattern of several horizontal series of bright red dots on the lower half of the body sides (versus no rows of red dots), tiny dark dots on operculum and cheeks in adult males (versus large dots or a vermicular pattern) and other aspects. It differs from its partly sympatric (having the same distribution) species H. severus in several morphological, behavioral and ecological aspects. The new species is a mouth-brooder, from which its specific name liberifer (Children carrier in Latin) was inspired, plus unlike H. severus it is found not only in black water but also in clear and white water, with a higher pH. H. liberifer is described from the Orinoco basin in Venezuela, but it can also be found in the Casiquiare River (that connects the upper Rio Negro and Orinoco basins) and in the middle and upper Rio Negro in Brazil.
Staeck, Wolfgang & I. Schindler. 2015. "Description of a new Heros species (Teleostei, Cichlidae) from the Rio Orinoco drainage and notes on Heros severus Heckel, 1840". Bulletin of Fish Biology. v. 15(n. 1-2), pp. 121-136