Built-In Snorkel? - elephant fetus - Brief Article

National Wildlife, Oct-Nov, 1999

Elephants' ancestors may have started out as aquatic creatures that used their trunks as snorkels. That's how researcher Ann P. Gaeth and colleagues at the University of Melbourne in Australia interpret evidence they recently examined from seven fetal elephants. Elephant gestation usually lasts for 660 days, and the ages of the subjects, which were from animals culled from an overpopulated park in South Africa, ranged from 58 days to 166 days.

Features that develop early are thought to be of more ancient origin than those that come later, so the scientists were on the lookout for clues to elephant evolution. They were amazed to find funnel-shaped tubes in the kidneys that are only found otherwise in freshwater fish, frogs and egg-laying mammals such as the platypus. The autopsies also revealed that the trunk develops very early; even in the youngest fetus, which itself was about the size of a pencil eraser, a tiny, well-developed trunk had already formed. Gaeth hypothesizes that trunks were an adaptation to life in the water. The new research adds to a body of existing evidence that elephants and sea cows (which include manatees and dugongs) evolved from the same aquatic forebear.