Using revolutionary four-dimensional scanning technology, scientists are able to shine a light on the hidden secrets of mammalian embryonic development. The film charts the fetal journey of three species of mammal – a litter of puppies, an elephant calf and a dolphin.
From conception through to birth, one thing becomes obvious – mammals undergo similar stages of development in the womb. In fact, in the early embryonic stages, it is not easy for the untrained eye to spot the difference between a dolphin, a dog, an elephant and even a human.
Elephant embryo at 11 weeks. Its limb buds and head are similar to that of a six-week-old human embryo. It is about 18 millimeters in size and weighs 1.5 grams.
The Asian elephant fetus (depicted here) is unique for its 22-month gestation period, the longest pregnancy of all mammals.
By 12 months the fetus looks perfectly formed.
At 12 months, an elephant fetus is an average of 18 inches long and weighs approximately 26 pounds. It can use its trunk, curling it right up into its mouth and over its head.
An elephant in the womb. This image is a model of a 19-month elephant foetus, almost full-term. The elephant is fully developed but will spend the remaining 3 months of gestation gaining 0.5 kilogrammes in weight each day.
Dog embryo at 30 days. It is approximately 2 centimetres in length – no larger than a grape. This is the dog embryo halfway through its gestation.
At 60 days in the womb, three days before birth, the puppy has developed a full coat of hair, with nails and paw pads, and the body is covered with touch-sensitive nerve endings.
Dog fetus at 60 days, nearly full-term. A full coat of hair, nails and paw pads are present.
Dolphin embryo at one month. It is around 1.5 centimeters long and has limb buds that it will lose as it develops. The heart is starting to beat.
At one month in the womb, dolphins develop tiny leg-like limb buds that vanish within two weeks, and the animals swim in amniotic fluid for the next 11 months of gestation.