Pygmy hippopotamus Pygmy hippopotamus The pygmy hippopotamus ("Choeropsis liberiensis" or "Hexaprotodon liberiensis") is a small hippopotamid which is native to the forests and swamps of West Africa, primarily in Liberia, with small populations in Sierra Leone, Guinea, and Ivory Coast. The pygmy hippo is reclusive and nocturnal. It is one of only two extant species in the family Hippopotamidae, the other being its much larger relative, the common hippopotamus ("Hippopotamus amphibius") or Nile hippopotamus. The pygmy hippopotamus displays many terrestrial adaptations, but like the hippo, it is semiaquatic and relies on water to keep its skin moist and its body temperature cool.
Pygmy marmoset a separate genus for the pygmy marmoset, as "Callithrix" is no longer paraphyletic. There are two subspecies described by Colin Groves of the pygmy marmoset: There are few morphological differences between these subspecies, as they may only differ slightly in color, and they are only separated by geographical barriers, including large rivers in Central and South America. The evolution of this species diverged in terms of body-mass from typical primates, with a high rate of body-mass reduction. This involves large decreases in pre-natal and post-natal growth rates, furthering the thought that pro-genesis played a role in the evolution of this