Why all the Shark Week mania over megalodon? Why two other sharks blow it out of the water

With all the fuss over megalodon lately (including the Discovery Channel’s doubled-down non-apology), we decided to give some attention to a couple of grossly unappreciated other prehistoric sharks. Great whites are great and all, and megalodon is a marvelous monstrosity, but there are two other prehistoric shark species that really blow everything else out of the water.

We get that megalodon is mega-huge, and it’s thrilling to ruminate over an extra-large, extra-hungry version of today’s Great White. But what about sharks with scissors for jaws? Or a buzz-saw mouth full of teeth?

It’s not science fiction. Here are two prehistoric sharks that we think should be in the running for their own Shark Week special:

Edestus

There were several species of this scissor-jawed prehistoric shark, the largest of which — Edestus giganteus — could rival the size of a modern Great White. But instead of regular shark teeth (which are pretty scary as is), Edestus had a mouth that cut like giant scissors.

“When you say ‘shark,’ the first thing that pops in your head is teeth,” says Associate Curator of Paleontology David Temple. “Sharks have had similar kinds of teeth, but there were some weird evolutionary offshoots where the teeth don’t look like we imagine them now. Instead of the rows and rows of teeth that we expect the mouth, Edestus’ mouth looked more like a modern dolphin’s, and its teeth were more like shearing scissors.”

Image courtesy wikimedia

Edestus wound up with its unusual, protruding shears (pictured above and reenacted here) because it did not shed its worn teeth like a modern shark would. Instead, new teeth continued to grow outward until its two rows of single-file teeth protruded out past its mouth.

Helicoprion

Also called the whorl shark, the Helicoprion is notable for its bizarre toothy set-up. Like Edestus, instead of shedding its old, worn teeth, Helicoprion retained them, adding new teeth in a single row in a spiral formation (imagine the growth pattern of the world’s longest fingernails, and you’ll get the idea.)

For years, Helicoprion’s remains confused scientists and an accurate body outline eluded researchers:

Photo courtesy Scientific American
The many faces of Helicoprion, courtesy of Ray Troll for Scientific American.

Recently, though, a report published in Biology Letters offered new insight into the shark’s unusual jaw. Instead of protruding past the lower jaw and coiling beneath the chin, as was once thought, or existing completely externally as some sort of defensive structure, scientists now believe that the shark — which had no teeth at all in its upper jaw — housed its “whorl” of teeth inside its lower jaw. To kill soft-bodied prey, it sliced upward like a buzz-saw, using this vertical spiral of teeth to push food back into its throat.

courtesy WikiMedia

A “whorl” of Helicoprion teeth

“Two of my fantasy acquisitions to the museum are paleozoic sharks,” Temple says of these often underappreciated freaks of the sea.

What say you: Should Discovery Channel devote a special to these super-special sharks?

On the Discovery Channel’s megalodon bungle: In defense of cryptozoology and critical thinking

For us, as for many science lovers, it’s currently our favorite season. Some might even call it the most wonderful time of the year: Shark Week.

The Discovery Channel’s annual full-channel takeover, devoted to all things predatory and sleek, is one of the single-most anticipated science events of the year. So we were a little disappointed — as, apparently, were many Discovery Channel viewers — when the network aired a film that implied that the extinct monstershark megalodon might not really be extinct.

We consider ourselves something of experts on the subject, because, well, this:

Megalodon Jaws
(That’s our Associate Curator of Paleontology, David Temple, with our Adult Education Director, Amy Potts, NOT being swallowed alive by an EXTINCT shark.)

We sat down with Associate Curator of Paleontology David Temple to dish over the epic bungle and set the record straight. Here’s his point-by-point breakdown of how wrong — WRONG WE TELL YOU! — it all is:

Point 1 (less a point than a fun fact):

The largest recorded (and verified) Great White Shark was caught off Prince Edward Island in 1988. It measured 20 feet long, meaning the 25-foot “Great White” featured in Jaws would have actually been more believable as a megalodon. The movie is, of course, fictional. Temple says there is a truism in diving that Discovery might have missed during its excitement over giant sharks: “Everything underwater looks a third bigger and a third closer than it really is, except for sharks. Then you can multiply that times 10.”

Point 2

For a threatened “living fossil” species to exist, they must retreat into the margins of their ecosystems. See: the Coelacanth. Megalodons required tropical, warm water to survive, and so for them, retreating into the depths of the ocean simply wouldn’t be a viable option.

Point 3

Megalodons were, as the Discovery Channel portrayed, extremely aggressive and proficient predators. As a result, their impact on their native ecosystems was great. If a population of megalodons yet existed, it’s impossible that we wouldn’t have noticed.

Point 4

If megalodons still existed, even in the cool depths where they couldn’t possibly survive, we would have seen a carcass by now. Even the Giant Squid, seen for the first time just last year, periodically washed up on shore to confirm its existence.

So in conclusion, while it’s fun to imagine a world in which megalodons still swam the seas (“Imagine Jaws on steroids,” says Temple); and while cryptozoologists chasing hidden and mythical creatures like the Loch Ness monster and Big Foot are occasionally right (see: the Okapi); you’d be far more likely to discover a small new species of frog than a 70-foot shark that could eat a fishing boat.

Point? Science.

The Bakker is back! Join renowned paleontologist Dr. Bob Bakker at Jurassic Jam this Saturday and Sunday

World-renowned paleontologist, curator of the new Morian Hall of Paleontology, consultant and character inspiration for the cult classic Jurassic Park: Dr. Bob Bakker is back in Houston and lighting up the halls of HMNS this weekend at Jurassic Jam.

Image here http://paleo-studies.tumblr.com/post/23628762217/featured-paleontologist-robert-bakker

The two-day event includes an adoption party at at the Museum Store, arts and crafts in the Herzstein Hall and a meet-and-greet with Dr. Bakker from 10 a.m. to noon on Saturday for new and veteran dino parents.

Admittance to meet Dr. Bakker requires a general admission ticket and a prehistoric pet (either adopted that day or previously taken in).

Then on Sunday, we’ll be screening Jurassic Park 3D with a special introduction by Dr. Bakker, who consulted on the film and is even name-dropped by young Joseph Mazzello (Timmy Murphy). A Q&A session will immediately follow.

To book your tickets in advance, click here!

Today in the Department of Mysteries: 12-year-old Robby uncovers “culturally modified” bone in Jersey Village

Occasionally we receive artifacts at the Museum uncovered by curious residents who are looking to have their discoveries identified. The latest comes from 12-year-old Jersey Village resident Robby, who took it upon himself to write Associate Curator David Temple the following (quite impressive) letter:

Dear Sir or Madam,

My name is Robby, I am 12 years old, and I was walking along in my backyard, playing by myself, when I felt something painful and sharp stick into my foot, so naturally I stopped to investigate. I felt around for the article that wounded me, and I concluded that it was a bone. I unearthed it and further found that it was a bone that looked like it was a washer joint (the kind that the spinal cord travels through), and I washed it off carefully to see if there were any further marks that could tell me if it was a dinosaur bone, but there was nothing. I was hoping that you could either radiometric date it, or DNA test it to see if it was. I have enclosed the bone in an envelope. Please let me know as soon as you find out.

Sincerely,

Robby
P.S.
2 days later, I found another bone that looked almost identical to the bone I found previously. It is a little bigger, and dirtier. Please respond!

"Culturally Modified Cow Bone" - the latest from The Department of Mystery

Temple looked over the bones and, upon concluding his research and determining their true origins, issued the following response on official Museum letterhead:

Dear Robby,

Thank you for your inquiry regarding the bones. When researching these things, particularly to which ancient animal a fossil bone may have belonged, a great place to begin would be a geologic map of the relevant area.

Geologic maps are peculiar; they are less about telling you how to get some place and more about telling where you are in time. The sediments that Jersey Village sits on are from the Quaternary within the Cenozoic; your backyard is outcropping the Beaumont Formation at the oldest, which gets you somewhere between 10,000 and 2 million years ago (give or take).

Pleistocene-aged animals lived on the sediments in your yard, and their remains could be buried in these sediments. No dinosaurs; however mammoths, mastodons and giant sloths all are animals that lived in the area during that time. I am enclosing a copy of the geologic map of Texas for your perusal. Find Houston and match the color on the key; where ever you find yourself, that’s where you are.

From careful analysis, we know your samples to come from an ungulate from the genus Bos. These pieces are not vertebra, but pieces from the legs of the animal. Though not old enough to be a paleontological sample, these do qualify for archaeological/anthropological analysis.

One thing I determined was that this animal was probably eaten by a sometime predatory species, likely Homo sapiens. I will say this conceding that the teeth and jaws of Homo sapiens are not adapted for chewing hard bones. You yourself noted the absence of marks on your sample bones, and I agree with your estimation and believe it significant.

Also, your samples do not bear any markings that would indicate primary feeding or secondary scavenging by Canis lupus familiaris, or Canis latrans. These animals are or were recently common in Jersey Village. Their teeth and jaws are well-adapted for crunching bone and leaving diagnostic traces of this feeding behavior.

Another bit of evidence pointing to primary consumption by a member of the genus Homo is that species’ nearly unique adaptation for making and using tools. Your sample bones show cultural modification, specifically butchering.

As mentioned above, the flat sides of the bones show them to have been modified with a saw, probably with the muscles attached. The smooth, even sides point to a mechanical, fine-toothed saw rather than a hand saw.  Considering practices in local culture, this bone and attached muscle were likely placed over a fire, for a short period of time, as the bones do not appear to be charred.

In archaeology, the three things to remember are context, context, and context. Were these bones by themselves or were there other objects with them? Bits of metal or glass maybe? If those objects are associated with the bones that would strongly support the “BGM” hypothesis below. Also the age of your home is a potential clue.

Before trash pick-up was available, garbage was frequently burned in the backyard and buried. While more charring over all surfaces on your bone samples would help support this, the absence of charring does not rule out the “Buried Garbage Model.” It is possible that there was a burn ban, or the responsible party for trash disposal just did a really bad job. Sadly there are questions science cannot answer, at least not without more fieldwork. Your sample could still have been buried, which would have kept it from being chewed by dogs or coyotes.

To summarize, you do not have a dinosaur, sadly. You did find the remains of a barbeque, shank steaks were served, they were likely served rare, medium rare, medium well at most. The bones were then thrown outside and the people either had no dog, and/or buried their trash. Your samples are not good candidates for radiometric dating; what is associated with the bones would be your best way of dating your site, but I would guess near the Late Recent.

I encourage you to keep looking down; you never know what you’ll find. If there is old glass or metal where you found the bones, be careful not to cut yourself when examining these fragments.

If you would like to go fossil hunting, get your parents to look up the Houston Gem and Mineral Society. They take regular trips to outcrops to collect fossils. If you want to know where dinosaur fossils in Texas might be found, the enclosed map has the answer. Dinosaur fossils can also be found locally at the Houston Museum of Natural Science.

I am returning your samples as I am contemplating becoming a vegetarian, and they make me hungry.

Sincerely,
David Temple
Associate Curator of
Paleontology

Robby’s samples were returned to him this week along with the Museum’s encouragement to keep curious. Tune in to the Beyond Bones for future installments from The Department of Mysteries.