Deep-Sea ‘Hoofprints’ Came From This Elusive Creature

What made these “hoofprints” at the bottom of the ocean? They didn’t come from Poseidon’s pony, a new study suggests.

The underwater imprints off the coast of New Zealand first caught scientists’ attention in 2013. Shaped like spades with secondary disturbances near the middle, they’re cut into the Pacific Ocean floor at about 450 meters.

Now, researchers with New Zealand’s National Institute of Water and Atmospheric Research (NIWA) have superimposed photos of a species of deep-sea fish over images of the imprints, rendering visually convincing evidence of their origin.

Superimposed rattail fish mouths on top of the markings.

Photo: Stevens et al., Deep Sea Research Part I: Oceanographic Research Papers, 2023


The imprints “line up perfectly” with the triangular snouts and bite patterns of some species of deep-sea rattail fish, the researchers told ScienceAlert.

It’s no wonder the prints threw marine biologists for such a long loop. Rattails (also known as “Grenadiers”) are particularly elusive bottom-feeders. If these are rattail bite marks, such evidence is “rarely, if ever, encountered,” NIWA wrote.


Scientists once observed rattail “rooting around” at a depth of 4,000m in the 1970s but they never found bite marks in the sediment.

NASA has claimed its maps of Mars and the moon are more complete than any that exist of the ocean floor. Researchers may have solved the decade-long “hoofprint” mystery, but it’s a reminder of the secrets that the deep sea can keep.

Sam Anderson

Sam Anderson takes any writing assignments he can talk his way into while intermittently traveling the American West and Mexico in search of margaritas — er, adventure. He parlayed a decade of roving trade work into a life of fair-weather rock climbing and truck dwelling before (to his parents’ evident relief) finding a way to put his BA in English to use. Sam loves animals, sleeping outdoors, campfire refreshments and a good story.