Mystery of ‘hoof prints’ at the bottom of the sea may finally be solved

The mystery of some ‘hoof-shaped’ markings discovered at the bottom of an ocean may finally be solved.

The markings, which are situated off the coast of New Zealand, were first found back in 2013 by New Zealand's National Institute of Water and Atmospheric Research (NIWA).

A survey being carried out on undersea ridge, revealed a smattering of what looked like hoof prints, at 450 meters deep. Probably not a horse then.

In the decade since, it’s not been clear what caused the markings - but now researchers think they may have the answer.

Marine biologist Sadie Mills from NIWA said: "NIWA uses a technology called the Deep Towed Imaging System (DTIS) to allow us to see the seafloor in stunning detail.

"When our people review this footage, they often see markings in the sediment, but unfortunately, most of them are unknown to science and we can only guess what might have made them, let alone find convincing proof."

Scientists reckon they've worked out what left these particular marks, however.

A new study has finally solved the decade-long mystery.

Deep Sea Research Part I: Oceanographic Research Papers

Scientists say the marks appear to perfectly line up with the mouth-shape of a species of fish called deep-sea rattail fish or grenadiers.

The team believes the markings are most likely ‘bite marks' from where the fish have bitten down on the mud to find some food.

Mills said: "It is so cool to finally have the validation that what we saw on the video was actually rattails feeding in the mud.

"It's like getting a nice reward at the end of many years of watching DTIS footage."

Stevens added: "The reason we could point to a specific species is because of their unique head features – these types of rattails have a long snout and an extendable mouth on the underside of their head that allow them to feed off the seafloor, something that other species do not.

Deep Sea Research Part I: Oceanographic Research Papers

"I had a hunch this might work but I was really surprised how well the head profile images matched the impressions."

The discovery is made all the more interesting, as it is some of the only evidence found that shows the feeding habits of grenadiers.

The fish usually look for food at such incredible depth that their bite marks are ‘rarely, if ever, encountered’.

The team said that they were not aware of any documented evidence of the natural foraging behaviour of this particular breed - meaning that as well as solving the mystery of the ‘hoof prints’, they’ve also managed to gain a pretty interesting insight into the eating habits of the fish.