Researchers visiting the Indonesian island of Sulawesi made a huge — and unexpected — discovery when they found the first frog known to give birth to live tadpoles.
"It was very reminiscent of the scene in Alien where the little monster explodes out of the stomach of the poor human who has been impregnated with that larval alien," Jim McGuire, a herpetologist at the University of California, Berkeley, told NPR.
A vast majority of the more than 6,000 frog species in the world give birth the same way: The female lays eggs in water, a male fertilizes them, and the eggs turn into tadpoles that become frogs. There have been a few exceptions, with one now-extinct species swallowing fertilized eggs and then later giving birth through their mouths. McGuire sees the live-tadpole birth as "another pretty crazy reproductive mode that's evolved within frogs. Frog biologists are turned on by that sort of thing."