Oddly enough, researchers say the teeth found in this remote corner of the world belong to just four shark genera

Nov 28, 2014 09:10 GMT  ·  By

In a recent paper in the Journal of Vertebrate Paleontology, paleontologists announce the discovery of thousands of shark teeth on Banks Island in the Canadian Arctic Archipelago.

The teeth, discovered by scientist Jaelyn Eberle with the University of Colorado Boulder in the US and fellow researchers, were unearthed during several expeditions. The paleontologists who found them say that they date back to the late-early or the middle Eocene epoch.

This means that the sharks that left them behind lived and died sometime about 53 million to 38 million years ago. As explained by Jaelyn Eberle and colleagues, the creatures thrived in the region because eons ago the Arctic was a much warmer place.

More precisely, it is estimated that in those days the Arctic had an average temperature of 8 to 14 degrees Celsius (46 to 57 degrees Fahrenheit) during winter and one of 20 to 25 degrees Celsius (68 to 77 degrees Fahrenheit) during summer.

A rather unexpected find

Writing in the Journal of Vertebrate Paleontology, University of Colorado Boulder specialist Jaelyn Eberle and fellow researchers detail that they first set out to explore Canada's Banks Island back in 2004, during the summertime.

What's interesting is that, at that time, the paleontologists weren't even thinking about probing the landscape looking for shark teeth. On the contrary, it was fossilized remains of mammals that the researchers hoped to find.

Unfortunately, the sites that they focused on failed to produce any fossilized mammal remains. Still, much to their surprise, the paleontologists found a whole lot of shark teeth, Live Science informs. They got so excited about these ancient chompers that, in 2010 and 2012, they returned to the area.

The teeth belong to oddly few species

The paleontologists explain that, having taken the time to study the over 8,000 teeth they unearthed on Banks Island, they found them to belong to merely four shark genera. Besides, the majority were left behind by sharks included in the Striatolamia and Carcharias genera alone.

“Probably the biggest surprise, at least at first, was that most of them – literally thousands of these things – belong to just two shark genera, and they are both within the sand tiger type of sharks,” researcher Jaelyn Eberle said in a statement.

As mentioned, the Arctic was a fairly warm place back in the Eocene epoch. Hence, the researchers behind this investigation expected to be able to document the presence of plenty more shark species in the region. Why these four genera alone populated the area millions of years ago remains a mystery.

One possibility is that, in those days, the water around Canada's Banks Island was considerably less salty than it currently is. Consequently, it was only sharks that could handle low salinity that managed to thrive in the area. As paleontologist Jaelyn Eberle put it, “You don't get a lot of sharks that can tackle that kind of low salinity.”

Over 8,000 shark teeth found on Banks Island (5 Images)

Thousands of shark teeth found on Canada's Banks Island
The teeth are said to be several million years oldSpecialists say they were left behind by sharks belonging to just four genera
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