Showing posts with label Megalodon. Show all posts
Showing posts with label Megalodon. Show all posts

Sunday, June 14, 2015

Jurassic World: Shed Teeth

At one point in the new Jurassic World movie, the main character Owen Grady (played by popular actor Andy Dwyer) pulls a broken tooth from the main monster Indominus rex from the shell of one of the Gyrospheres.  Believe it or not, broken teeth just like this are incredibly important for paleontologists when it comes to studying many different aspects of dinosaur habits and behavior!  First, let's take a quick look at the anatomy of a dinosaur tooth.
A pair of Tyranosaurus rex tooth casts with my camera lens for scale.
In the picture above, both teeth belong to the famed tyrant lizard king Robert California Tyrannosaurus rex itself!  The tooth on the top is larger, but it wouldn't have appeared that much larger in the mouth of the animal.  The reason behind that is the darker brown part on the left of the tooth is actually the root of the tooth, and would have been inside the animals skull.  The tooth underneath, the darker brown one, is a shed tooth crown.  Dinosaurs, unlike mammals, have an infinite supply of teeth, and if they lost a tooth it simply didn't matter!  They would grow another one in its place in a few weeks.
Stan, the Tyrannosaurus rex skull on display at the Morrison Natural History Museum.  Look on the upper jaw.  See the largest tooth, just about in the middle of the tooth row?  Let's zoom in and take an inside look! 
This is a view from the inside of the Tyrannosaurus skull from above, a view that the lawyer from Jurassic Park probably didn't find quite as fascinating.  See the largest tooth in the middle of the picture?  Notice how there's another little bump at the top of the tooth row, where the teeth are emerging from the maxilla bone.  That's actually another tooth growing in underneath!  If we CT scanned the original fossil, you'd be able to see all sorts of teeth growing in underneath!
Here we have a dental battery of the famous Triceratops, on display at the Rocky Mountain Dinosaur Resource Center (RMDRC) in Woodland Park, Colorado.  Now take a look at the picture below. 
Here, we have an individual tooth of Triceratops, out of the dental battery that you can see in the picture above.  This specimen is from the Hell Creek Formation of South Dakota, and also on display at the RMDRC.
The reconstructed jaws of the enormous, sixty foot long shark Megalodon, on display at the Mace Brown Museum of Natural History at the College of Charleston in South Carolina.  Like other sharks, as well as dinosaurs, you can see the several rows of teeth in the jaws of this guy, as well as the enormous biceps on the arms of the sexy Chris Pratt look-alike on the right.  Biceps for scale are approximately 36 inches in diameter.
Here and below, we have pictures of part of the dentary of the large carnivorous theropod dinosaur Torvosaurus from the Late Jurassic Morrison Formation.  You can see on the end in the picture above, the tooth is growing in, while the rest of the teeth are pretty well established.  This fossil is on display at the University of Colorado Museum of Natural History in Boulder
Another shot of that Torvosaurus dentary seen above, you can see another tooth growing in as well, second from the left.
Shed teeth can be quite important for paleontologists when it comes to determining behavior of these extinct creatures.  When paleontologists discover shed teeth of an animal, it can be a good indicator that the dinosaur was feeding on something nearby.  Unfortunately, shed teeth are easily recognized as fossils by most laymen, and are therefore often picked up by the public or fossil collectors looking to make a quick buck, thereby destroying any information we could potentially gain from such knowledge.  With good samples of shed teeth, like those employed by paleontologist Dr. Robert Bakker at the Late Jurassic Morrison Formation site of Como Bluff in Wyoming, scientists can learn about dinosaur diets, habits, habitats, and behavior, such as group movement, pack hunting, and even whether dinosaurs cared for their young!
A shed tooth crown of a Tyrannosaurus on display at the RMDRC.
Several shed phytosaur teeth on display at the Denver Museum of Nature and Science.  Phytosaurs were distant cousins of dinosaurs, and looked a lot like crocodilians.
A shed tooth of Nanotyrannus, a small cousin of Tyrannosaurus rex, from South Dakota.
Leidyosuchus, a type of Cretaceous crocodilian, with several shed teeth.
Brachychampsa, another Cretaceous crocodilian.
In 1877, local geologist Arthur Lakes discovered the very first bones of the dinosaurs Stegosaurus armatus and Apatosaurus ajax in Morrison, Colorado, and if you check out the Morrison Natural History Museum, you can actually see them there today!  Surrounding the genoholotype of Apatosaurus ajax, the very first specimen called YPM 1860, was reported by Lakes to have seven shed teeth belonging to an allosaur surrounding the specimen.  This indicates some that the predatory allosaurs were actually feeding on the Apatosaurus, which is very interesting information for paleontologists to have!  Below are two pictures of part of that YPM 1860 specimen, with the Director and Chief Curator of the Morrison Natural History Museum Matthew Mossbrucker pointing to the shed allosaur tooth crown.  These pictures are from the collections of the Yale Peabody Museum in Connecticut.
Shed allosaur tooth crown in the matrix of YPM 1860.  Photo Credit: Matthew Mossbrucker 
Shed allosaur tooth crown in the matrix of YPM 1860.  Photo Credit: Matthew Mossbrucker
Non mammals rarely have more than one type of tooth in their mouth, and when they do, it can often be the cause of celebration.  For example, in our previous post about the Latin and Greek root of two, we discussed two animals called Dimetrodon and Dimorphodon.  Dimetrodon is an early ancestor of modern mammals, and its name means "two measures of teeth," as it has two different types of teeth in its mouth.  Dimorphodon is a type of pterosaur (sometimes referred to as pterodactyls), a distant cousin of Pteranodon, whose name means "two morphs of teeth," again in reference to the fact that two types of teeth are in the animals mouth.  The animal below is a dinosaur called Heterodontosaurus, who belongs to the eponymously named family of dinosaurs, the Heterodontosauridae.  As you can see in the picture below, Heterodontosaurus has several larger teeth in the front of their mouth, and smaller teeth in the back.
Heterodontosaurus, a small little Early Jurassic dinosaur from South Africa.  As you can see, there are two different types of teeth in their mouth, larger ones in the front and smaller ones in the back.
One of the things that make mammals special is our teeth.  One of the most classic features of us mammals is our varied teeth.  In us humans, we have our incisors and canines in front, and our chewing molars in the back.  Since most mammals were only about the size of a shrew back during the Mesozoic Era, the time of the dinosaurs, in many places such as Como Bluff in Wyoming, paleontologists rely almost exclusively on the teeth of the tiny little mammals, since the teeth are much harder and more durable than the rest of the skeleton.  Below, we have a trio of elephantid molars on display at the Mace Brown Museum of Natural History at the College of Charleston in South Carolina.  Look at how varied the teeth are!  The first two belong to animals whose teeth were better adapted for crushing and grinding tougher vegetation, while the last molar would have been better for mashing up grasses.
Cuvieronius tropicus, a Pliocene-aged elephantid from South Carolina.  Large, high-cusped molars for crushing and grinding tougher vegetation.
Stegomastodon mirificus, a Pliocene and Pleistocene-aged elephantid, discovered in the Ashepoo River of South Carolina.  Like Cuvieronius, Stegomastodon also has those large, high-cusped molars that are great for demolishing tough plant matter.
The Imperial mammoth (Mammuthus imperator) from the Pleistocene of Florida.  These guys have a similar design of tooth to the dental battery of the ceratopsian dinosaurs mentioned above.  The duck-billed dinosaurs, or hadrosaurs, also had a similar design.  These teeth are broad and flat and good for mashing up grasses.
Shed teeth can be pretty important when paleontologists study fossils and extinct animals.  They are good at establishing behavior, and can be pretty important for long-term studies of paleoenvironments.  So when Owen uses the shed Indominus tooth in Jurassic World, believe it or not, that's actually something that paleontologists do from time to time!

Tuesday, August 13, 2013

The Truth Behind the "Truth" Behind Megalodon

Today, the great white shark rules the seas and haunts our imaginations.  After the release of the 1975 movie "Jaws," the great white shark and other sharks were feared and loathed more than they already were, although much of this fear was unbiased.  Ever since Jaws, hundreds of books, movies, television programs, and more have all capitalized on the shark craze, producing everything from the fantastic Steve Irwin Crocodile Hunter specials to the recent TV movie Sharknado.  One of the most popular shark-related features in the media is Discovery Channels "Shark Week," an annual event that features a week of shark-related programs.  Although many of these programs, as is to be expected for television programs nowadays, push the limits of reality, I think that the premiere of this year's Shark Week went too far, and I'm not the only one who thinks that, either.

First off, let's meet the star of this program: megalodon.  Estimates of the size of megalodon have varied widely and wildly, with some older estimates as high as about 100 feet long.  Today, however, most scientists agree that the largest megalodon could grow to around 60 feet long.  Which is still pretty massive, given that most great white sharks don't exceed lengths of around 20 feet, and look at how much people are afraid of them!  megalodon would have easily been able to swallow the average human in one bite: just take a look at those reconstructed jaws, below!  Also, below that picture, make sure to check out the size of just one megalodon tooth.  Suffice it to say, this shark was one massive bruiser.  This shark WAS one massive bruiser.  Notice how I emphasized the "was?"  Well, that's because megalodon went extinct about two million years ago.
Pyg encounters a mid-sized megalodon tooth, graciously donated to my collection of fossils and things that I take to local schools by local paleontologist Wayne Itano
Megalodon sounds pretty awesome, right?  I mean, to be honest, it's one of those extinct animals that just doesn't need to be "sci-fied up," because it's already cool enough as is, on par with other animals such as Tyrannosaurus, Spinosaurus, and Utahraptor.  Well, just because it didn't NEED to be sci-fied up doesn't mean that television networks didn't do it anyways.  And this years Shark Week premiere was the culprit.  Discovery Channel aired a two hour "documentary" showing "biologists" on the hunt for a megalodon.  Today.  In the present.
One of those extinct animals that just doesn't need to be "Hollywoodized!"  Meet Stan, the resident Tyrannosaurus rex at the Morrison Natural History Museum!  You can see Pig seated in the bottom jaw for scale!  Yeah, this guy was huge.
We have no evidence to indicate that megalodon is alive and with us today, and the "evidence" included in the "documentary" was very clearly doctored.  For example, below is a picture of a whale that has supposedly been bitten in half by a megalodon:

And here is a photo "uncovered from Nazi archives" of a giant shark fin surfacing behind a pair of U-Boats:

The first picture just screams CG.  And the second one....really?  Nazi's? Very Indiana Jones-esque.  OK then, Discovery.

The "documentary" starts off with "found footage" of a "boat capsizing off the coast of South Africa and several people being eaten, but whose bodies were never recovered."  Already, this reeks of a typical television plot.  Especially given the fact that a quick Google search of this supposed incident, as well as any of the "biologists" in the "documentary," yields diddly-squat.  Apparently the prospect of a giant shark brutally attacking and destroying a fishing boat just wasn't exciting enough to make it to the news, despite the fact that every news story relating to sharks and shark attacks spreads like wildfire.  Perhaps the South African press was just busy that day?

People refute our naysaying by pointing out that "we know more about the surface of the moon than the ocean," and "the coelacanth (which you can learn more about by clicking HERE) and the giant squid were only discovered recently!"  Yeah, that's true.  But megalodon is very different from a giant cephalopod or a five or six foot long fish.  We are talking about an active, 60 foot long predator that's feeding on much, much bigger prey than the giant squid or coelacanth would.  The giant squid and coelacanth eat a lot of fish, and are considered to be primarily piscivorous.  The giant squid, although very large, is by no means at the top of its food chain, and is fed upon by the largest of the toothed whales, the 60 to 70 foot long sperm whale.  And two million years ago, megalodon would have made up the final link in this food chain, feeding on the 60 to 70 foot long sperm whale.

Am I saying that there is no possibility that more giant animals exist in the deepest depths of the ocean, just waiting to be discovered?  No, I most definitely am not.  I do, however, encourage you to consider the ecological resources that would be needed by such a massive animal.  With no evidence of mutilated whale carcasses that could be attributed to such a massive animal, and an equal amount of evidence from first-hand accounts....I think that the conclusion should speak for itself.

The biggest issue that I have with all of this is not that a television program was made that packages myths, untruths, and exaggerations: it was with the fact that they packaged it as a documentary, no quotations this time.  Discovery tried to balance out the fact that they blatantly made stuff up to appease some of their viewers by pointing out that they included disclaimers in the show.  Yeah, true, there were disclaimers: but click HERE to see how short and hazy these disclaimers really were.  The disclaimers read:

None of the institutions or agencies that appear in the film are affiliated with it in any way, nor have approved its contents. Though certain events and characters in this film have been dramatized, sightings of "Submarine" continue to this day. Megalodon was a real shark. Legends of giant sharks persist all over the world. There is still debate about what they might be.

Notice how they never really say that none of it was true.  When he gave a press release, the executive producer of Shark Week, Michael Sorensen, said that “With a whole week of Shark Week programming ahead of us, we wanted to explore the possibilities of megalodon.  It’s one of the most debated shark discussions of all time, can megalodon exist today? It’s Ultimate Shark Week fantasy. The stories have been out there for years and with 95 percent of the ocean unexplored, who really knows?”  The part that bugs me the very, very most about that statement is the line "It's one of the most debated shark discussions of all time."  It isn't, I promise you.  It really, really isn't.  I have never heard of any paleontologist who seriously believes that megalodon swims the oceans today.  There might be some paleontologists who won't discount the possibility, which is fine.  Science changes all the time.  But with a complete and total lack of evidence, no serious scientist will really debate that sort of thing.

There's many more issues that people have had with this presentation, varying from thousands of people on social media voicing their complaints, all the way to actor Wil Wheaton, who wrote about the megalodon fiasco on his blog, which you can read HERE.  Others, such as popular paleo writer Brian Switek, went to Twitter:

I do hope that this backlash will cause the people at Discovery, as well as at other television stations, to reconsider what they make into a television program, and consider the possibility that, just maybe, there's a significant chunk of people out there who don't want to be fed this garbage.  I do hope that this causes some changes in any future programming, and if we are all really lucky, this event might spawn a South Park episode.  You have to admit, it'd be pretty perfect.  Let's just cross our fingers, shall we?

Monday, August 12, 2013

Meet Pyg!

Meet Pyg, the Triceratops hatchling! Pyg is the blog's new mascot, and will be using her unique blend of entertainment and education to help teach people about her long-lost world. Make sure to follow her on her exploits! I'll be using Pyg to help make our subject matter a little more fun, because, lets face it: dinosaurs are boring. Wow, I'm totally joking, no they're not, they rock! I'm actually with Grace Albers up in Dinosaur National Monument in Utah right now, so you'll probably be seeing some pictures from that trip pretty soon! However, tomorrow we will be talking about the recent Discovery/Megalodon controversy, so make sure to tune in then!



Thursday, October 11, 2012

The Denver Gem and Mineral Show Part 2: The Piscivores (Excepting Penguins)

As we started talking about a few weeks ago, my friend Masaki Kleinkopf and I were able to visit the Denver Gem and Mineral Show at the Denver Merchandise Mart.  Last time, we talked about the giant ammonites, the baby eryops that Dr. Robert Bakker was working on, the gliding Indonesian lizards of the genus Draco and the pterosaurs that evolved from creatures purportedly much like this millions of years ago.  Today, we are going to talk about all of the piscivorous animals that we saw there, except for the fossil penguin that I saw there.  Knowing me, that would easily take up one whole post of its own there.  Keep in mind throughout this post that I'm not certain for all of these animals that they actually eat fish, I just know that the large groups that they belong to often eat fish.  Today, we are going to be looking at the mosasaurs, crocodilians, pterosaurs, sea lions, other fish, sharks, and the dreaded piscivorous dinosaur Spinosaurus.  

MESSAGE FROM ZACK FROM THE FUTURE:  Hello, everyone.  This is Zack Neher.  I have travelled to this post from the future.  I wanted to give you a link to the Homebase for these posts.  I am like Rose Tyler, leaving clues in the form of Bad Wolf.  Except this is not quite like that at all really.  Anyways.  The Homebase for the series is HERE.
Myself next to a gigantic mosasaur skull
I am pretty sure that this is the skull of a mosasaur , anyway.....it looks more like a mosasaur skull than the skull of a crocodilian, if you ask me
A mosasaur jaw, from Morocco by the looks of it
A mosasaur skull (Platecarpus, if memory serves, but it is entirely possible that I am wildly off) in front of a fossil ray
Another huge mosasaur skull
We also got to see the teeth of a piscivorous pterosaur.  The teeth of a piscivore are usually different from those of other carnivorous animals due to their conical shape.  The teeth of the fish eaters, like those of crocodilians and dolphins, are usually conical in shape, to prevent prey from struggling out of their grasp.
The teeth of a piscivorous pterosaurs
Below are the skulls of various crocodilians.
 
 
The skulls of these dudes seem like they should be out of a cartoon or something, they are so weird and comic looking!
Here are a pair of photos of fossilized sea lion teeth, both from the extinct sea lion Imagotaria sp., from the Miocene to Pliocene in the Atacama region of Chile.
Imagotaria sp., from the Miocene to Pliocene in the Atacama region of Chile
Imagotaria sp., from the Miocene to Pliocene in the Atacama region of Chile
Next, a picture of a pair of fossil jellyfish!
Fossil jellyfish!
Next are the teeth of the gigantic, fifty to sixty foot long carnivorous (or actually, piscivorous) dinosaur: Spinosaurus.  Also in the picture are the teeth of another enormous carnivorous dinosaur that lived in the same area of Northern Africa as Spinosaurus at this time of the Cretaceous Period: Carcharodontosaurus, who was not a piscivore, at least not primarily a piscivore, like a penguin, or as Spinosaurus is purported to
be.  (Did you see that alliteration?  My language arts teacher would be most impressed).  I discuss both Spinosaurus and Carcharodontosaurus in two previous posts, which you can look at HERE FOR SPINOSAURUS and HERE FOR SPINOSAURUS AND CARCHARODONTOSAURUS.
The teeth of Spinosaurus.  Actually in this shot, it looks as if most or all of these teeth belong to Spinosaurus.
And now for some pictures of the teeth of Megalodon, the largest shark that is ever known to have lived!  I have talked about Megalodon in the past, click HERE to learn more.

 


Now for some random ones.
It's a fish eat fish world out there
A pair of shark jaws.  I am not certain as I don't remember at all and they are unlabeled, but I believe them to be jaws of sand tiger sharks.  Again, I could be totally off on this!

Wednesday, August 8, 2012

Top Ten: Extinct Sea Monsters (Part 1 of 5)

Since ya'll kinda get gypped on Wednesdays with the "What Is It?" challenge, I decided that, when I do do the challenge, I will also include a "Top Ten" list.  I mean, come on now, who doesn't like lists?  I know some of my friends would be absolutely and completely lost without them!  So for today's "Top Ten," we are going to take a look at some of the world's most amazing, extinct sea monsters.  This is also up for debate, so if you disagree, just give me a holler!  Also, they are not in any particular order, I just kind of threw them all in there!  So without further ado, here we go, with our "Top Ten:  Extinct Sea Monsters!"

1.  Megalodon - This gigantic relative of the extant great white shark was thought to be simply massive: perhaps even sixty feet in length!  Living the world over, Megalodon stalked the seas during the Miocene and Pliocene Epochs, and only died out during the current Pleistocene Epoch, around two million years ago.  It is thought that Megalodon evolved to such gigantic proportions in order to be able to attack the massive whales that had started to evolve in the cooler seas of the Miocene and Pliocene.  Remember now: if it's a shark, then it's a fish!
A tooth fragment from Megalodon at this excellent restaurant called The Crab Shack on Tybee Island off of the coast of Savannah, Georgia. 
2.  Basilosaurus - A massive, predatory whale (and, therefore, a mammal) that cruised the seas in the Late Eocene Epoch, 40 to 34 MYA, fossil discoveries of this massive animal were reportedly so common in the southern United States during the early 19th century, that bones of Basilosaurus would be used as furniture!  It was first discovered in Louisiana, and is the state fossil of both Mississippi and Alabama.  Basilosaurus has also been found in Egypt and Pakistan.  At around sixty feet in length, the same estimated length of Megalodon, Basilosaurus is thought to have been the biggest creature alive at the time.

COMING UP:

3.  Liopleurodon
4.  Shonisaurus
5. Elasmosaurus
6.  Dunkleosteus
7.  Archelon
8.  Leedsichthys
9.  Tanystropheus
10. Tylosaurus

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE
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