Don't forget the lovable Manatee. They exist in the Congo river, though only as far up as Livingston Falls, but they live in the Niger river all the way up to the Inner Delta, one of the biggest freshwater swamps in the world. Manatees just need a lift upriver to establish themselves in the Congo.
Credit National Geographic
It's not quadrupedal, but it is herbivorous, gentle and exceptionally cute when taking a nap. Like the sightings of other aqueous creatures, reports are often conflicting, fear clouds judgement and rumors spread quickly. Manatees are also known for their mistaken identity in relation to mermaids
###Evolution
Evolution
From the wikipedia entry:
Sirenia is the order of placental mammals which comprises modern "sea cows" (manatees and the Dugong) and their extinct relatives. They are the only extant herbivorous marine mammals and the only group of herbivorous mammals to have become completely aquatic. Sirenians are thought to have a 50-million-year-old fossil record (early Eocene-recent). They attained modest diversity during the Oligocene and Miocene, but have since declined as a result of climatic cooling, oceanographic changes, and human interference. Two genera and four species are extant: Trichechus, which includes the three species of manatee that live along the Atlantic coasts and in rivers and coastlines of the Americas and western Africa, and Dugong, which is found in the Indian and Pacific oceans.
Manatee share a common ancestor with elephants.
###Related Extant Species
Related Extant Species
Amazonian Manatee
Dugong
West Indian Manatee
###Interesting note on Dugong.
Interesting note on Dugong.
Dugongs' or sea cows' hides have been thought to have been used as coverings in the building of the Old Testament portable worship tent known as the Tabernacle.
A cave painting of a dugong – Tambun Cave, Perak, Malaysia
