TikToker finds alien-looking shark egg with a tiny, moving embryo inside at the beach

• A viral video on TikTok shows an alien-looking shark egg found on a California beach.
• The corkscrew-shaped egg came from a California horn shark, the TikTok user said.

A Tiktoker's viral video shows a fascinating discovery: an alien-looking, spiral shark egg and the tiny, moving embryo inside.

TikToker @California.Shelling posted the video showing off the unique find earlier this week. She wrote that she found it washed up on a California beach and wanted to answer questions people had.

In the video, she shows the egg — which she says came from a California horn shark — is pliable and squishy but will harden over time.

At one point in the video, the camera gets close enough to the egg casing to see the tiny, wriggling embryo inside.

David Ebert, the program director of California's Pacific Shark Research Center at Moss Landing Marine Laboratories, told Science Friday that the shark egg casing "usually firms up relatively quickly."

While that shark pup is on its own until hatching, Ebert told Science Friday the egg comes with "a little lunchbox of nutrients that the developing embryo will grow off of."

That "lunchbox" should last until the shark hatches, according to the National Marine Sanctuary Foundation.

"Every egg case contains one shark pup, which takes between six and nine months to hatch depending on environmental conditions and genetics," the foundation said.

Plenty of TikTok users had questions about the odd corkscrew shape of the egg, but it does have a purpose.

Female horn sharks can lay eggs every 11 to 14 days, the National Marine Sanctuary Foundation said, and the eggs are protected by that corkscrew-shaped casing. The twisting shape allows the female shark to "wedge" eggs "into small cracks and crevices in the environment to hide them from potential predators," the foundation said.

At the end of the video, the TikToker put the egg in a rocky tide pool, hoping it would stay safe until hatching.