SHARKS ARE KIND OF NOTORIOUS FOR HAVING TEETH – it is, after, all the principal reason we fear them. But they’re also famous for losing them. And some of us diving human beings are famous for hunting shark teeth.
In fact, sharks drop teeth continuously. Inside their powerful jaws, they have multiple rows of choppers. When one falls out, one behind it moves forward to take its place, as if on a conveyor belt. Over its lifetime a shark can produce and lose more than 30,000 teeth.
The propensity for shedding dental structures means that shark teeth are a commodity, findable and available as souvenirs, fossilized scientific artifacts, collector’s items worth money.
HUNTING SHARK TEETH
On a liveaboard trip off the Great Barrier Reef some years ago, we were treated to a feeding frenzy of gray reef sharks. In this case the crew used ropes to work a barrel of fish parts for the frenzied carnivores to attack while we kept to the sides watching. Interesting, some exciting photos, a standard shark feeding frenzy.
Beforehand, the crew told us that, following the feeding, we could go search the sands in the feeding are for shark teeth. The feeding frenzy of sharks was matched by the divers’ frenzy for finding their teeth.
And search they did, hunting shark teeth by spreading out throughout the dive area, sifting through the sands. I confess, I don’t remember if any divers found any teeth. I just remember the intensity with which they searched. As a photographer, I was more interested in the photo opp than the teeth.
YOU ARE HOW YOU EAT
It’s actually very difficult to tell what species of shark a lost teeth came from. There are too many variables. It is generally possible to identify the animal down to the genus level.
But generally, sharks’ teeth fall into a handful of shapes and designs that vary according to their methods of earning their livings.
- Nurse and angel sharks, for example, tend to sport dense flattened teeth, useful for crushing the bivalves and crustaceans on which they prey.
- Blue sharks and bull sharks rely on needle-like teeth to grip slippery narrow prey like stingrays, squids, flounders and other small to medium fish.
- Great whites and other sharks that prey on larger fish and marine mammals like seals and dolphins rely on pointed lower teeth and triangular upper teeth, utilizing serrated edges to cut larger victims into small, edible portions.
- Plankton feeders like whale sharks and basking sharks do have teeth, but they’re non-functional. They filter their planktonic meals through their gills.
THE MEANING OF SHARK TEETH
Teeth play a large role in our understanding of sharks, especially of their evolutionary history. As animals with skeletons based on cartilage rather than bone, cartilaginous bones and softer tissues survive the dissolution of time only under rare circumstances.
But teeth that fall into sediment may be protected from the decaying process of oxygen and bacteria. Absorbing minerals in the sediments – “permineralization” – the tooth fossilizes. This generally takes at least 10,000 years.
In a shark’s mouth, the teeth truly are pearly whites, just as Mac the Knife says. Loose teeth you’re likely to find preserved in sediment or on a beach are more likely to be black or brown or gray. This reflects the minerals that have replaced the actual tooth.
As a result, shark teeth are prime signposts in our understanding of shark evolution, from the earliest shark-toothed candidate known (Doliodus problematicus, a 410-million-year-old fossil), through the Carboniferous Period (the “golden age of sharks” beginning some 359 million years ago), and the arrival of the youngest surviving group of sharks, the hammerheads (probably some 23 million years ago).
HUNTING SHARK TEETH, MEGALODON MANIA VARIETY
Still, when people think of shark teeth fossils, they mostly think about megalodons. Probably the largest fish ever to live on the planet, megalodons measured up to 60 feet in length, although most were probably smaller. In comparison, a great white today maxes out at 20 feet, if that. Megalodons appeared some 16 million years ago and, fortunately for us, went extinct some 2.5 million years ago.
But during their run of 14 million years, they dropped a lot of teeth, big ones. The largest megalodon tooth ever found measures 7.5 inches in length; the largest great white tooth comes in at about 3 inches.
THE VALUE OF SHARK TEETH
There are numerous sites on the web discussing hunting for shark teeth, often at the beach and for fun. Still, for serious collectors, shark teeth have value, and there are sites selling fossilized shark teeth, especially megalodon teeth.
One site I found offers a 6.7 inch megalodon tooth for $9,995, and a cretaceous sand tiger shark tooth for $21,995. On this site, megalodon teeth 5 inches in length are more in the $300-$500 range.
Even megalodons had to start out as babies, and teeth from juveniles, like the 1.5-inch one I have, seem to run more in the $20 to $35 range.
PRINCIPAL SOURCES: Marine Biology, Fourth Edition, Peter Castro, Michael Huber; “Fossil Shark Teeth,” Florida Museum; “Shark evolution: a 450 million year timeline,” Natural History Museum; “Shark Teeth Facts,” Animals-HowStuffWorks; “Shark tooth,” Wikipedia; “How to Find Shark Teeth,” SharkSider.com; “Fossil Shark Teeth for Sale,” Fossilaria; “Natural Megalodon Teeth,” sharksteeth.com.