A “graveyard” of fossilized shark teeth was recently discovered by Australian scientists 3.1 miles (4-5 km) deep in the Indian Ocean. This jaw-dropping site, found in October 2022, had more than 750 shark teeth of modern and prehistoric mega sharks.
Scientists made this surprising discovery during a month-long voyage at Cocos (Keeling) Islands. Commonwealth Scientific and Industrial Research Organization (CSIRO) scientists say it is incredible that they found so many shark teeth in such a small area deep in the sea.
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Dr. Moore, a scientist aboard the ship, said, “it’s incredible to think that we’ve collected all these teeth in a net from the sea floor some 4 to 5 km below the ocean surface.”
The discovery of ancient mega-shark fossilized teeth
Among the discovered shark teeth were fossil teeth from close ancestors of the infamous megalodon. The megalodon was the apex predator that ruled the sea 23 million years ago. It is estimated to have been 49 to 59 feet long (15 to 18 meters). So, imagine a shark more than 3-4 times larger than the biggest great white shark ever recorded.
It knows what roamed the sea before this massive shark is even more interesting. And this discovery will shed some light on the 40-foot close ancestor of the megalodon.
Incidentally, they made this discovery during the last day of their biodiversity survey. After 26 attempts to capture fish for their research, they got this surprise from the ocean’s depths.
In an interview with Live Science, Diane Bray recalled, “it was our last trip sample before heading back to Australia. So I was disappointed when we hauled up the net because it was filled with mud.”
“We tipped the contents out on the boat’s deck, and as we went through everything, we found shark tooth after tooth. We were finding teeth from [modern] mako and [great] white sharks, but also fossilized teeth from ancient sharks like the immediate ancestor of the giant megalodon shark,” she added.
Diane is the lead collections manager at the Museums Victoria Research Institute.
Is this a shark graveyard site?
Sharks are mostly made of cartilage, meaning they don’t leave behind preserved skeletons. Usually, the only remains you can find are scales and teeth. So, experts must rely on fossilized shark teeth to understand the ocean’s ancient life. And to estimate the size of the ancient mega sharks.
The size of the teeth collected from this deep sea site range from 0.39 inches (1 cm) to 4 inches (10 cm) long. Apart from the black manganese nodules that had developed on them, they were in good condition. The most extensive megalodon tooth fossil ever found measured 7.48 inches (18.9 cm).
Researchers aren’t entirely sure why there were so many fossilized shark teeth in this Indian Ocean site. But they believe that the area is not a massive shark cemetery. According to Bray, hundreds of sharks could not have died at this site.
Scientists believe that a community of sharks probably lived here. The more plausible explanation is that the sharks shed their worn-out teeth here because they have an infinite supply of teeth that they replace throughout their lives. This region in the Indian Ocean was part of an ancient reef and a haven for ancient sharks.
Importance of ocean biodiversity studies
This discovery shows the benefits of protecting unique marine environments. Both the Cocos (Keeling) Islands Marine Park and the Christmas Island Marine Park were established in March 2022. They are the latest additions to Australia’s numerous marine parks.
Scientists aboard the RV Investigator have also made other significant finds. For example, they have discovered a “small, stripey horn shark,” new to science. And according to John Keesing, the current chief scientist on the voyage, about a third of the species captured in recent biodiversity surveys may be new among scientists.
These scientific marine expeditions may help governments protect land and sea animals. Not only do they open a portal to past and present marine life, but they also provide a way to preserve our future.