embryos and foetuses, and found the animals shared key features with aquatic creatures such as frogs, fish and manatees. Most compelling, the researchers said, was the discovery that the embryos had nephrostomes, or funnel-shaped kidney ducts found in fish, birds and egg-laying mammals such as echidnas. Ann Gaeth, a doctoral candidate at Melbourne University, and colleagues at the Royal Women‘s Hospital in Carlton said the findings complement other recent evidence that suggests elephants are closely related to sea mammals such as dugongs and manatees. "The evidence from our embryological study of the elephant suggests that it evolved from an aquatic mammal," Gaeth‘s team wrote. Fossil remains of a group known as Tethytheria, which include the ancestors of elephants, manatees and an extinct creature called Desmostylia, indicate an aquatic life as well. To better understand the possible link, the Australian researchers studied elephant embryos taken from female elephants shot in South Africa‘s Kruger Park as part of an effort to reduce the elephant population in the wildlife sanctuary. Looking at developing foetuses and embryos is a time-honoured way to discover clues about an animal‘s ancestry and, with a gestational period of 660 days, elephants offer a long period for examination. onto dry land, they preserved the aquatic environment of the embryo by encasing it in a fluid-filled amniotic sac, and functional nephrostomes are still present in the first stages of development of … egg-laying reptiles and all birds," they wrote. They are never found in mammals that bear live young. The team also uncovered other possible features indicating elephants evolved from an aquatic mammal. Dugongs, or sea cows, have a similar physiology, and the researchers said scientists presume animals like seals and whales, which evolved on land and returned to the water later, once had testes in the scrotum like other land mammals but retracted them into the abdomen to protect them from the chilling, and sterilising, effects of water. Finally, there were the tiny trunks of the foetuses, visible even in the smallest one. "The trunk might have first evolved as an adaptation to an aquatic environment," they suggested. "For example, it could have been used as a snorkel, as it is to this day when elephants swim in deep water."