Now we have the opportunity to learn more about the reproductive cycle of these extraordinary creatures.  This Sunday, May 10 at 9pm, the National Geographic Channel is airing a full documentary called In the Womb: Extreme Animals.  Using 4D ultrasound images and fetal imaging techniques, the two-hour special will highlight bizarre, sometimes gruesome, activity such as the parasitic wasps’ larval development inside the body of a young cabbage white caterpillar and the lemon sharks’ embryonic cannibalism.

Watch a clip of the documentary featuring how a penguin fetus uses a complex and clever adaptation to get oxygen while inside the egg:

2 week old red kangaroo joey in the pouch.  (Photo credit © Hannah James / Pioneer Productions)

An Emperor penguin chick embryo inside its egg after about one week’s gestation. (Photo credit © Steve Gomez / Pioneer Productions )

Model of a mid stage Lemon Shark embryo.  (Photo credit © David Barlow Photography)

Parasitic wasp successfully oviposits her eggs into a newborn caterpillar.  (Photo credit © Hans Smid / Pioneer Productions)

For more info, see the National Geographic Channel: Extreme Animals website or catch the program on Sunday, May 10, at 9pm.

Beautifully illustrated with ultrasound images of these animals as embryos and fetuses, the book highlights the development of unique physical characteristics that the animals will come to rely on once out of womb.

For example, one section showcases the elephant fetus after four months. At this point, the trunk is recognizable, but it will need the full 18 more months in the womb to continue developing. Once out of the womb, the elephant will use this strong, highly dexterous snout to pick foliage, carry objects, suck water, and use as a snorkel while swimming.

The author also touches upon physical characteristics that provide clues about the animals’ ancestry.  For example, at 3-4 weeks, the dolphin fetus develops hind limbs which later retract and disappear. This suggests that dolphins may have evolved from four-legged land animals.

Intertwined with the three main stories are captivating glimpses into the development and behavior of red kangaroos, emperor penguins, sand tiger and lemon sharks, and parasitic wasps. These mini stories reveal the extraordinary journeys these animals make before they’re even born, as well as provide interesting points of comparison to the three main characters.

It is a fascinating read for animal lovers, but parents should note that reproductive behavior is covered in detail.

The book, In the Womb: Animals, is available at National Geographic’s Online Shop as well as Amazon.com.

You may also be interested in purchasing the documentary DVD, In the Womb: Animals.