Unlike mammals giving birth, this tidal-zone snail has recently switched to live birth. Its new version of birthing offspring into the world without using eggshells is quite different. These types of snails are called periwinkle, these periwinkle moms give birth to multiple baby snails a day. Unlike humans, it’s probably not the moms that do the hard work but the babies that do the hard labor.

Egg-laying periwinkle snail relatives have a jelly gland that creates a weird goo substance that acts like a protective mass of eggs outside the mom’s body. But in Littorina saxatilis the gland has changed, and evolved into a certain type of womb or a brood pouch. Inside it, eggs still form there, but they don’t come out until after they hatch. “As a long-time observer of the snails, she doubts that the snails, even push at all,” says Johannesson. The little periwinkle babies may have crawled out of the mother’s body and into the outside world all by themselves.

The way these babies are born fascinates scientists because some species most likely developed this ability over 100,000 years ago. Yet live birth doesn’t look like it came from a major genetic change. Instead, differences in their genetics might have happened bit by bit, from changes in some of the 50 regions in snail, genes.  

Giving the eggs more protection might explain the success of this species. A researcher says, even though the newborns emerge from their moms looking vulnerable and only half a millimeter long. They simply come out of the mother, pouch and quite often you can see them crawl around inside her through their shell. The mom might not help them emerge but she sure does help them get their first meal, bacteria ready to be eaten of her shell.