An unborn elephant, tiny but perfect in every way. A dolphin swimming in the womb, just as it will have to swim in the ocean the moment it is born. An unborn dog panting.
Each one amazing and now, thanks to these remarkable pictures, they can be seen for the first time.
Using an array of technology, the images reveal what until now has been a secret - exactly how animals develop in the womb. They were created by the same team who in 2004 showed how human embryos "walk in the womb".
The rest of the story, and more photos