Pygmy hippopotamus occur. The common hippopotamus gives birth and mates only in the water, but pygmy hippos mate and give birth on both land and water. Young pygmy hippos can swim almost immediately. At birth, pygmy hippos weigh 4.5–6.2 kg (9.9–13.7 lb) with males weighing about 0.25 kg (0.55 lb) more than females. Pygmy hippos are fully weaned between six and eight months of age; before weaning they do not accompany their mother when she leaves the water to forage, but instead hide in the water by themselves. The mother returns to the hiding spot about three times a day and calls
Chacoan pygmy opossum separated from this species as "G. formosus". Finally, Voss et al. (2004) erected the new genus "Chacodelphys" for the species. Chacoan pygmy opossum The Chacoan pygmy opossum ("Chacodelphys formosa") is a recently described genus and species of didelphimorph marsupial. The only species in Chacodelphys, "C. formosa", was known until 2004 from only one specimen collected in 1920 in the Chaco of Formosa Province, Argentina. The species is gaining popularity as a pocket pet. The Chacoan pygmy opossum is the smallest known species of didelphid. It has a head-body length of 68 mm, a tail of 55 mm and a hind