No I Did Not Mean Triceratops, I Meant Ceratops

Recently, the folks over at the Best Western Denver Southwest purchased yet another fossil cast for their amazing hotel!*  This time, the cast is of a skull nicknamed "Judith," a specimen that is referred by some paleontologists to the dinosaur genus Ceratops.  And, no, I didn't mean to say Triceratops.  Don't feel bad if you haven't heard of Ceratops montanus: as a matter of fact, I hadn't really heard of it either until several weeks ago, when Greg Tally informed me that the Morrison Natural History Museum would soon be receiving a very large box in the mail!  Judith is still in the Cretaceous Room here at the MNHM, where she will stay for at least a few more weeks.  I really didn't know much at all about this dinosaur, and was eager to learn more.  Unfortunately, there's not much out there, as Ceratops is based on just a few bones that were discovered in the late 1800s.  Despite the lack of material, Ceratops does have a pretty fascinating history, and is an incredibly important dinosaur; not because of what has been discovered about the fossils themselves, so much as what these fossils resulted in.

Greg Tally peers through one of the fenestrae (literally means "window" in Latin) in the skull of Judith, the Ceratops montanus skull for the hotel that is temporarily on display at the Morrison Museum.  Photo Credit: Greg and Meredith Tally

When it comes to giving an animal or a group of animals a scientific classification, there are a lot of hoops you have to jump through, and a bunch of rules you have to follow.  Sometimes, groups of animals are named after the best known and understood animal in that group.  For example, Stegosaurus is the genus of dinosaur that defined the group of animals called the stegosaurs, and Tyrannosaurus is the genus of dinosaur that defined the group of animals called the tyrannosaurs.  Sometimes, it isn't quite as simple.  Think about it this way: Las Vegas is easily the most famous city in Nevada, and I'm sure I'm not the only one who spent a significant portion of their childhood thinking that Las Vegas was the capital of Nevada.  However, it is Carson City that holds the official title of capital.  Even though Las Vegas receives much more attention than Carson City, the state of Nevada isn't simply going to change where its capital is, and to the best of my knowledge, a change like that never really happens.

Although that comparison was a bit of a stretch and had about as many holes as the skull of Chasmosaurus, I think you get my point.  The same thing goes for scientific names.  Although Triceratops is the best known individual of the dinosaurian group called the ceratopsians, this group is still called the ceratopsians, as opposed to being called the triceratopsians.  That's because it was Ceratops, and not Triceratops, that was described by scientists first.

Ceratops montanus, temporarily on display at the Morrison Natural History Museum.  Photo Credit: Greg and Meredith Tally

The year was 1888, and paleontology in western North America was still going strong.  We've talked about the Bone Wars between paleontologists Othniel Charles Marsh and Edward Drinker Cope before, and we are going to revisit Marsh in this post.  To maximize the number of fossils he could describe, Marsh called upon the talents of a large number of fossil collectors, including the always brilliant Arthur Lakes in Morrison, Colorado.  Another of these collectors was a man named John Bell Hatcher.  Although Hatcher should also be remembered for a large number of his contributions to paleontology, for our purposes here we remember Hatcher as the man who discovered Ceratops.  On a trip to a known dinosaur fossil site near the Judith River in Montana, Hatcher discovered a number of fossils.  One of these fossil discoveries was composed only of a pair of horn cores.

Doesn't sound like much, does it?  Well, truth be told, it wasn't, though it was enough for Marsh to realize that he had something new.  If you click HERE, you can view the two page paper that Marsh published in 1888 that briefly described this new discovery as an animal called "Ceratops montanus."  There are several things of interest that we should take away from this paper, some of which are:

1. Marsh originally suspected that this new creature was "nearly allied to Stegosaurus of the Jurassic, but differs especially in having had a pair of large horns on the upper part of the head."  Marsh got the location of the horns right, but the close relation to Stegosaurus.....not so much.  Given the enormously tiny sampling of bones he had to work with though, it's not a surprise that Marsh compared this new animal to something that he already knew a good deal about.  Keep in mind that this is the very first scientific description of a ceratopsian dinosaur, so Marsh just had to go off of what had already been discovered.  Which was nothing.
2. Marsh notes that the "position and direction" of the horns could be likened to the enormous Meiolania, an extinct turtle from Australia, as well as the lizards in the genus Phrynosomax, the horned lizards.  He also notes that amongst the dinosaurs, the "only known example of a similar structure....is the single median horn-core on the nasals of Ceratosaurus," a mid-sized theropod dinosaur from the Late Jurassic Morrison Formation.   
3. In 1887, the year before this paper was published, geologist Whitman Cross sent Marsh a pair of horn cores about two feet in length and six inches across at their widest point.  Discovered right smack dab in the middle of where Denver, Colorado is today, Cross relayed to Marsh that they had been discovered in beds of Cretaceous rock.  Marsh, however, decided that these horns must have belonged to some sort of enormous bison, and gave the horns the name "Bison alticornis."  Perhaps Marsh was still suffering from the misconception that the 1887 discovery was, indeed, an enormous extinct bison, as these 1887 Denver horn cores are not mentioned in the brief Ceratops paper.  It is mentioned, however, that if the horns were discovered "detached," their "resemblance in form and position of the posterior horn-cores to those of some of the ungulate mammals is very striking," and the horns would "naturally be referred to that group."  I have no evidence to support my hypothesis, but I wonder whether this comparison to the mammalian ungulates is insurance on the part of Marsh, as perhaps at this point he had recognized the true nature of the 1887 horn cores.  This is pure conjecture on my part, and is mostly irrelevant anyways, as in 1889 Marsh recognized the dinosaurian nature of the Denver cores, and referred them to the genus Ceratops.  Today, these horn cores are regarded as belonging to Triceratops.
4. Marsh mentions that several limb bones, vertebrae, and teeth were also found in the Ceratops horizon, as well as several bits of dermal armor, and states that he believes they also belonged to Ceratops.  Whether this is true or not I do not know, but what I do know to be false is Marsh's next sentence, in which he states that the bones "indicate a close affinity with Stegosaurus, which was probably the Jurassic ancestor of Ceratops."  The specimen is housed in the Smithsonian today, under the catalogue number USNM 2411.  A search through the online records of the Smithosonian shows that 2411 consists only of a partial skull, which seems to be consistent with what I've read in other sources.  I'm not sure whether these other skeletal elements mentioned above have found a definitive dinosaurian home, or whether their true owner is uncertain.  
5. The final paragraph is, in my opinion, inarguably the most important.  The paragraph reads as follows: "The remains at present referred to this genus, while resembling Stegosaurus in various important characters, appear to represent a distinct and highly specialized family, that may be called the Ceratopsidae."  In this paragraph, Marsh has created the group of dinosaurs that, more colloquially, we refer to as the ceratopsians.  Or, more colloquially than that, "those dinosaurs that look like Triceratops with those horns."

Ceratops was discovered in what scientists now call the Judith River Formation.  Several other ceratopsians have been discovered in this formation, and due to the small amount and fragmentary nature of the material that was originally described as Ceratops, most paleontologists consider the dinosaur to be a nomen dubium.  Nomen dubium pretty much means that the material is too fragmentary for it to be diagnostic, and can't really be used in the future to determine whether new specimens are the same as the original or not.  Whether or not the newly discovered Judith specimen currently on display at the Morrison Museum is, indeed, Ceratops is still up in the air, as the paper has not been published yet.  Almost all of my Ceratops knowledge is out on the table for all to see, so I am not going to speculate or attempt to draw conclusions about something that I don't really know enough about to have an informed opinion on.  Guess we will just have to wait and see!  In the meantime, come on by the Morrison Natural History Museum and the Best Western Denver Southwest to see Judith, and much more!

*If you've been living underground amongst worms and fossils for the last few months, you might not have heard of the hotel, so you can check out some incredible pictures of the best Best Western by clicking HERE and HERE.

Works Cited:

Did Velociraptor Hunt In Packs?

Ever since the movie Jurassic Park came out in 1993, people from all over the world added the name Velociraptor to their often-short list of dinosaurs they had heard of, joining more famous dinosaurs such as Tyrannosaurus, Stegosaurus, and Triceratops. While the dinosaurs portrayed in the movie have often been hailed as “ahead of the times,” Steven Spielberg of course had to make some assumptions about dinosaur behavior.

Michael Crichton, the author of the original Jurassic Park book, did too, which can be clearly seen when reading both of his Jurassic Park books. In the first one, a theory was circulating that Tyrannosaurus had eyes like a frog, that would be unable to see something so long as it didn’t move. This is reflected in the way Dr. Alan Grant, one of the protagonists in the novel (as well as the subsequent movie) tells his comrades to react when they are spotted by a Tyrannosaurus: just don’t move. (Don’t blink. Don’t even blink. Blink and you’re dead.)  

However, this theory was debunked by the time that it came for Crichton to write his next dinosaur-themed book, The Lost World, a sequel to Jurassic Park.  In the sequel, Ian Malcolm, who was also a protagonist in the first novel, moves to the forefront. He explains that the Tyrannosaurus from the first novel was probably just not hungry enough to attack them, and that it was just toying with them. A clever way of seamlessly working that scientific transition into the books without disrupting the canon of the story!*

Spielberg also played a lot of things up throughout the movies to make it more cinematic and exciting: and, to be honest, I can’t really blame him, at least not as critically as some paleontologists do. (That, however, is a story for another time). Today, however, we are going to be talking about one cinematic Spielbergian leap, and the resounding effect it has had on paleo-enthusiasts the world over: the idea of raptors hunting in packs.

In the books and movie, the Jurassic Park raptors are portrayed as clever, cool, and calculating killing machines with the intelligence of a dolphin or an ape. Scientists know, however, that while animals such as Velociraptor and Troödon may have been smarter than their mammalian counterparts of the time, their intelligence nowhere near reaches that of some modern day cetaceans and primates. Most people don’t want to accept that, though: they want their dinos really smart!

Here’s my stab at psychology for the day. In my semester long psychology course that I took last year, we discussed something in a relationship and everyday life called a fiction. Essentially, when human beings have feelings for someone, they develop what we call “fictions” in their mind. Fictions  about physical appearance, fictions about intelligence, and fictions about other redeeming qualities as well. If two people are projecting these fictions onto each other, then a relationship can develop. On the other hand, sometimes these people are confronted with these fictions, and they realize that they are not all that they are cracked up to be. When these people fall short of their fictions, some emotional turmoil can result. In my opinion, the reality of the Velociraptor, as well as the reality of the rest of the dromaeosaurs, falls short of people’s expectations. I think a similar thing is occurring right now with dinosaurs and feathers: people want their T-rex scaly, not feathery! That might be why many people seem so opposed to the idea.

“All right,” people say. “So Velociraptor wasn’t a genius. It still hunted in packs, though, right?” It seems like a fairly obvious answer: “Of course they did! ….Right? I mean….if you think about it….” It’s when you start to really think about the evidence that this idea really falls apart. First, let’s look at a related animal called Deinonychus. Deinonychus is a mid-sized dromaeosaur, about thirteen feet long, and weighing about as much as a wolf. Living during the Early Cretaceous Period, between about 118 – 110 MYA, remains of Deinonychus have been found in the western United States. Deinonychus remains aren’t always found solo, however: in some cases, it looks like Deinonychus might have dined and died! At several different sites, Deinonychus remains have been found buried in close proximity to a large herbivorous ornithopod called Tenontosaurus.  Shed teeth from multiple animals seems to indicate that these animals might have been feeding together. Some paleontologists take this a step further, and propose that, not only did these animals feed together, but they lived and hunted together, too!

In this post, I am going to be using several modern-day analogues to point out flaws in some theories. (We’ve already done it with the deer!)  This time, we’re flying over to Indonesia to visit the Komodo dragon. The Komodo dragon is a very interesting animal that, like many other animals, will resort to cannibalism. The young Komodos take to the trees, hiding up in branches to light to support the weight of the adults.  The Komodos lead a generally solitary existence: that is, until it comes time to feed. At feeding time, the dragons will swarm all over the carcass, each fighting for a stake of the meal. To an outsider, unaware of how the animal had been killed, it might be interpreted that perhaps this was a family group that worked together to bring down a much larger prey.

Another comparison I like to make is a theoretical one. Imagine that a pride of lions has subdued a zebra on the plains of Africa. After they have eaten their fill, they move off into the shade to sleep off their recently acquired weight. Immediately afterwards, the vultures swoop in on the kill. Suddenly, somehow a flash flood overtakes the carcass and the vultures, leaving them buried in mud, sand, and silt. Over the next few thousand years, their remains fossilize. One million years later, paleontologists come across this find. To their eyes, it would appear, for all intents and purposes, like the vultures ganged up in a pack to subdue this one-toed creature. Maybe not the best comparison, but one that I always like to think about.

So does the evidence seem to allow us the conclusion that multiple Deinonychus fed together? I would say yes, the evidence does support that conclusion. Does the evidence support the conclusion that multiple Deinonychus lived together, and worked together to bring down the Tenontosaurus? In my opinion, I don’t think that that is enough evidence. Other paleontologists disagree, however, leaving the matter open for debate. Right now, what we need is a good fossil trackway.

Pyg learns about several baby Apatosaurus tracks at the Morrison Natural History Museum.  Together, these tracks create a trackway, which has revealed some very interesting behavior about these young sauropods!  To learn more, make sure to check out the museum's Facebook page HERE!

We’ve talked about trackways on the blog before. Fossil trackways are also often good evidence for group moving. We have many trackways that show groups of dinosaurs, such as sauropods, moving together in multi-age herds. We’ve talked before about the exciting conclusions that paleontologists are drawing by studying blocks of fossil footprints at the Morrison Natural History Museum. While fossil footprints aren’t always necessarily the final say, they are simply one more piece of the puzzle. And when it comes to dromaeosaur footprints, footprints that many different paleontologists agree belong to a dromaeosaur, we have none. Zilch. Zero. Nada. No dromaeosaur footprints. Not yet, anyways. So there’s one possible line of evidence down the drain.

Pyg compares her foot to the smallest baby Stegosaurus footprints in the world, also at the Morrison Natural History Museum!  These footprints us gain insights into social behavior, animal size, and locomotion.

Thus far, it doesn't seem like we have any evidence in FAVOR of Velociraptor hunting in packs. But evidence can work both ways: what about evidence AGAINST Velociraptor as a pack hunter? As a matter of fact, there is one main line of evidence that I find to be, if not conclusive, highly indicative of the truth being the pack hunting. This line of evidence comes from the environment that Velociraptor would have lived in. Velociraptor inhabited what is now the Gobi Desert of Mongolia between around 70 and 75 million years ago, during the Late Cretaceous. Back then, the Gobi looked a lot like it does today: deserty. Now, this is very important. Think about desert animals today, specifically the carnivores, but the herbivores as well. Although the desert is certainly not a lifeless place, it is by no means a party like the African Serengeti, or the great plains of North America (before the railroads came through and people killed almost all of the bison). There simply isn't enough food for large animals to get by, especially not large groups of them.

Now think about a standard predator/prey ratio seen in environments today. Let's talk about my home-state of Colorado. There are lots of places to hike in Colorado, and in almost any part of the state you can see some sort of deer, be it mule deer, white-tailed deer, elk, or moose: you name it, you can probably see at least one of these cervids at almost any place in Colorado. Now, consider this: how often do you see bears in Colorado? Or mountain lions? Not terribly often, and especially not very often when you consider how often one sees deer. That's because of the predator/prey ratio. Essentially, if the balance between predator and prey is not kept in check, then populations will crash. Therefore, it is imperative that the prey species outnumber the predator species by what is usually a significant margin, otherwise the predators will overhunt, and they will starve to death. (For a more complete discussion of the predator/prey ration, this time in the context of the lynx/hare cycle of Canada, click HERE).

Some predators can get away with hunting in groups or packs because the prey species are relatively abundant. For example, the African Serengeti. The prey density is just so incredibly high that many different types of predators, such as lions, hyenas, and African wild dogs, can all hunt in packs. It works for them, because there are just so many prey species there!

Now let us bring our attentions back to the deserts. You can walk for miles, you can drive for even more, and see hardly a sign of any vertebrate life. Most likely, all you will see is a vulture or a hawk soaring the thermals high above you, watching for its next meal. If you're lucky, you might see a deer, or possibly even a javelina (a pig-like creature native to the south western United States, as well as Central and South America). You aren't going to see a lot of them, though. And if the prey isn't plentiful, then the predators sure aren't going to be, either!

Although dinosaurian-dominated ecosystems were undoubtedly different in some aspects from the mammalian-dominated ones of today, the fundamentals of the predator/prey ration would still stand true. There just wouldn't have been enough food to go around for these animals to have been pack hunters!

So, the final question: did Velociraptor hunt in packs? Or didn't it? If I had to hazard an answer, I would say no, no they did not. Due to the extreme lack of evidence in favor of this social behavior, as well as some evidence that seems to indicate that they wouldn't have, I would say that they did not hunt in packs. Obviously, with future discoveries, my ideas may change, which is one of the great things about science: we are always learning new things! And who knows: maybe one day, it will be one of YOU who discovers that crucial bit of evidence that shows that Velociraptor did, indeed hunt in packs!

OK, that was WAY too cheesy to leave like that. I felt uncomfortable even writing it. Let's end on a joke, instead. Why couldn't T-rex clap its hands? Huh? Give up? Because he was dead. Thank you ladies and gentlemen, I will be here all week.

A special thanks to Matthew Mossbrucker and Robert Bakker for their helpful information in making this post!

*To be honest, the whole concept of the theory doesn’t make a lot of sense: think about modern-day deer as an analogue for extinct prey species. If they see a predator, they are going to freeze, as it is much more difficult to pick out a still animal from the surrounding landscape than it would be a moving animal.  So predators would have to be able to pick out the prey, otherwise it would never capture one.  This freezing behavior on the part of deer when they are startled also explains why deer often freeze in front of car headlights: deer in the headlights!

Dinosaur Provincial Park

As we talked about IN A PREVIOUS POST, dinosaurs are pretty big in Canada.  A large number of dinosaur species have been discovered up there, and one of the best places to find dinosaurs is a place near Calgary in Alberta called Dinosaur Provincial Park.  As a matter of fact, Dinosaur Provincial Park is a UNESCO World Heritage Site, along with 981 other properties "which the World Heritage Committee considers as having outstanding universal value."  Other famous sites include the Great Barrier Reef in Australia; the Galápagos Islands; Stonehenge; the Grand Canyon; and "Memphis and its Necropolis," the site of the Great Pyramids and the Great Sphinx of Giza!  Just to name a few.  Do you get the idea, though?  Dinosaur Provincial Park is kind of a big deal!

But why?  What makes a bunch of badlands with some dinosaur bones in them so important to Canada, much less a committee dedicated to protecting such international treasures as the Great Barrier Reef and the Great Pyramids?  What makes Dinosaur Provincial Park so GREAT?  (Get it?  Nevermind, it wasn't that funny anyways.)  Here's what the UNESCO website has to say about the park:

The property is unmatched in terms of the number and variety of high quality specimens, over 60 of which represent more than 45 genera and 14 families of dinosaurs, which date back 75-77 million years. The park contains exceptional riparian habitat features as well as "badlands" of outstanding aesthetic value.
The committee also included two main criterion that show why the park is so important:

Criterion (vii): Dinosaur Provincial Park is an outstanding example of major geological processes and fluvial erosion patterns in semi-arid steppes. These "badlands" stretch along 24 kilometers of high quality and virtually undisturbed riparian habitat, presenting a landscape of stark, but exceptional natural beauty.


Criterion (viii): The property is outstanding in the number and variety of high quality specimens representing every known group of Cretaceous dinosaurs. The diversity affords excellent opportunities for paleontology that is both comparative and chronological. Over 300 specimens from the Oldman Formation in the park including more than 150 complete skeletons now reside in more than 30 major museums.

Wow. Well that's a pretty big deal!  According to the website, between 1979 and 1991, a grand total of around 23,347 fossils were collected, including an amazing 300 dinosaur skeletons!  As mentioned above, the dinosaur skeletons represent every known group of Cretaceous dinosaurs.  (I assume that they mean every group that is known to live in North America at the time.)  Not only does the sheer amount of fossils allow for a more complete view of an extinct ecosystem, new dinosaurs and other animals have been discovered there, as well as potential behavior that can be inferred from the fossils! 

During the Late Cretaceous North America was divided by the Western Interior Seaway, a shallow, continental sea.  (To learn more about the seaway, check out a recent post I did on it by clicking HERE).  In Dinosaur Provincial Park, you can find the remains of both ocean going animals and land dwellers, as well!  The park is, of course, famous for its dinosaurs (as you could probably tell from its name).  But many of the marine creatures entombed in the rocks there and in the surrounding area are pretty awesome, as well!  For example, Hybodus, an interesting shark!  

Before we get to the dinosaurs, let's check out a few other cool creatures found in the park!  One of these is a creature we mentioned in a previous post: the post entitled "There Be Dragons," all about the monitor lizards!  In the post, I had a picture of a prehistoric monitor lizard named Palaeosaniwa attacking a flock of Ornithomimus.  Well, both of these creatures have been found in the park!  Below is the picture, created by talented paleo-artist James Field!  You can check out his website HERE!

Many animals have been discovered in the park, including turtles, crocodilians, and a ton of plants, but the only other non-dinosaur we are going to look at for now is a small little primitive marsupial mammal called Eodelphis!  Eodelphis, whose name means "early opossum," is thought to have weighed a little over a pound which, astonishingly, means that it was one of the largest mammals of its time!  It is thought to be related to Didelphodon, another Mesozoic marsupial mammal, who we shall meet in an upcoming post!

Now for the dinosaurs!  I'm going to start with an animal called Centrosaurus.  A ceratopsian dinosaur (just like Triceratops), thousands of individuals specimens of Centrosaurus have been discovered in a massive bonebed that extends for hundreds of meters!  While paleontologists disagree as to exactly what killed all of these animals, and in such immense numbers, the prevailing theory is that this was a herd of animals that drowned while trying to cross a river.  The individuals that make up the herd vary widely in age, which is one of the lines of evidence which supports the herd idea.  This is important evidence for paleontologists, as it indicates that these animals lived in groups!  

Another dinosaur that is found in the park is the small pachycephalosaur called Stegoceras, who is not to be confused with the similarly named and much more famous Stegosaurus!

Here is another fun dinosaur, called Chirostenotes!  This oviraptorosaur was first found in the park, and is definitely quite funky looking!

Dromaeosaurus, a distant cousin of Chirostenotes and a closer relative of the famous Velociraptor, was also first discovered in the park!

Just as Dromaeosaurus has been pushed from the limelight by Velociraptor, so too has Daspletosaurus been pushed by Tyrannosaurus!  Daspletosaurus is a tyrannosaur as well, and was first discovered in (surprise surprise) Dinosaur Provincial Park!  Two more Dinosaur Provinicial Park natives (and firsts) are Euoplocephalus, one of the tank-like ankylosaurs, and Parasaurolophus, a hadrosaur or duck-billed dinosaur!

I can't WAIT to visit the park one day!  In the meantime, HERE is a link to the park's website so you, too can plan your visit!

Calgary on Dwellable

Xiphactinus: The Inception Fossil

If you were to travel back 100 million years from where I live in Colorado, the face of a very, very different planet would emerge.  I suppose emerge isn't necessarily the best word in this context: submerged is more of an adequate description!  You see, unlike the mountains you would see in Colorado today, Late Cretaceous Colorado was even flatter than present-day Kansas....and a whole lot closer to sea level!  Between about 100 and 70 million years ago (MYA), an enormous seaway stretched northwards from the Gulf of Mexico, and southwards from the Arctic.  Within these waters, hundreds, perhaps thousands of animals flourished, many of which we have nothing like today.  Massive sea turtles like Archelon slowly swam through the waters, while the long-necked plesiosaurs cruised around, snapping up fish before they even knew they were there.  While sharks and mosasaurs were probably the most impressive denizens of the seaway, these massive carnivores fed on fish as well.  And the subject of today's post is one of those fish: a 17-foot long beastie called Xiphactinus.

Due to the numerous pictures uploaded to Pinterest by the Best Western Denver Southwest hotel (read more about it HERE), I'm going to be using a lot of pictures from this site!  Make sure you check it out by clicking HERE!  Unless otherwise noted, photo credit for all of the pictures in this post goes to that Pinterest page!

Why did I call Xiphactinus (pronounced zye-FACT-un-us) "The Inception Fossil?"  Well, that's a description that I came up with (don't ever let anyone tell you otherwise!) that has to do with one of the most interesting things about Xiphactinus: numerous specimens of the fish have been found with the remains of other fish in its stomach!  Just as the premise behind Inception is "a dream within a dream," so too are specimens of Xiphactinus sometimes "fish within a fish!"  The specimen below is a thirteen foot Xiphactinus that died with a fish known as Gillicus arcuatus in its stomach!

Unlike sharks, Xiphactinus would have been unable to bite off chunks of flesh from its prey, and instead would have had to swallow its prey whole, which is what makes the Inception Fossils so spectacular!  Some paleontologists propose that this lack of chewing may have been what killed some of these Xiphactinus specimens, and that they actually choked to death on their last meal!  I suppose it's possible, but I don't actually know enough about these specimens to be a very good authority on them!

The next three pictures below are pictures that I took of a specimen that I saw a week or so ago.  Long story short, my friends Isabel and Sam Lippincott and I had gone to a presentation given by paleontologist Dr. Ian Miller about the Snowmastodon Project a few months back, and he was impressed with Sam's paleo drawings when we showed him after the lecture.  He invited us to come on down to the Denver Museum of Nature and Science so that he could show us around behind the scenes, which he very kindly did a few weeks ago!  These are pictures I took of the 80 MY old Mancos Shale specimen of Xiphactinus, which was discovered in 1966 by some kids who had been hunting with their dad near Snowmass in Colorado.  They had stumbled across the rib cage of the animal, and had notified the Denver Museum.  The next summer, the museum excavated the remarkably complete, 13-foot specimen, taking it back to the museum, where it has been stored to this day!

Here are some more cool pictures from the Pinterest page!  This is a diorama of paleontologist Charles Sternberg caught in the act of discovering one of his "Inception fossils!"

And here are another pair of reconstructions of Xiphactinus!

Make sure to check out the Pinterest page of the Best Western Denver Southwest by clicking HERE!

The Stegosaur Song (Stegosaurus Week)

The second of a pair of songs that I made especially for Stegosaurus Week!  "The Stegosaur Song" to the tune of "The Mexican Hat Dance."  Below is the link to the song:

Here are the lyrics to the song:

Full Lyrics:

Primitive stegosaurs they are all found in China, England, France, and Tibet
Lexovisaurus and Regnosaurus and a stegosaur not named quite yet
Chialingosaurus and Craterosaurus and Jiangjunosaurus too
Next we have the huayangosaurs from China and so far they number but two

[Chorus:]
Oh, the plates and the spikes like the head of a trike with them you definitely don't want to mess
The stegosaurs lived in the Jurassic but some lived to the dawn of the Cretaceous

Chungkingosaurus and Huayangosaurus and now we move on to the set
Gigantspinosaurus and then Kentrosaurus and Loricatosaurus you bet
Those last three were all primitive stegosaurids but still thought to be more advanced
There are two more still Paranthodon and Tuojiangosaurus I bet you're entranced

[Chorus]

The dacentrurines are the second to last of all the groups of stegosaurus
Dacentrurus who gives name to the group Miragaia and then there are no more
The stegosaurines are the last of the bunch Stegosaurus most notorious
Hesperosaurus and Wuerhosaurus and last of all Hypsirophus

[Chorus]

Are you diggin' the songs?  Well, then check out our playlist below!

CLICK HERE TO BE DIRECTED TO A FUN-FILLED PLAYLIST OF AMAZING SONGS.

Want to learn more about Stegosaurus and it's relatives?  Well, check out the Homebase for Stegosaurus Week HERE to partake in more of the festivities! 

Museum Spotlight: The Heritage Museum of the Texas Hill Country

When we drove down to visit my Gramma Roo in Texas in December of 2011, we went to this fantastic museum called the Heritage Museum of the Texas Hill Country.  Although pretty small, the museum was still utterly fantastic!  Built next to a number of tracks from the Cretaceous Period, the museum was an excellent way to learn all about the local paleontology and geology of Canyon Lake and the surrounding area!  First off, we have a picture of a reconstructed theropod dinosaur named Acrocanthosaurus, the presumed trackmaker.

Next, we have a ton of pictures of the trackways and footprints that are assumed to belong to Acrocanthosaurus!

 

 

 

Now, in the picture below, do you see the parallel marks leading towards the Acrocanthosaurus reconstruction?  Those are thought to be the track of an odd-looking snail whose shell is really long and kind of flops over to the side, where it drags and leaves that mark!  Pretty crazy, huh!

Before we left, I looked around and found a lot of fossils all over the place!  The area was chock-full of them!

Photo Credit: Julie Neher

On our way out, we passed by this enormous ammonite.  It had to be two feet wide, at least!  It was incredible!

HERE is a link to the website for the museum!  It is most definitely a place worth checking out if you are ever down in that area! 

Canyon Lake on Dwellable

There Be Dragons

I think when it comes to reptiles, easily the most interesting are the monitor lizards and their relatives.  The monitor lizards are scientifically known as the members of the genus Varanus within the family Varanidae (which, in turn, is a family within the superfamily Varanoidea), and are widely considered to be the lizards with the most intelligence.  The largest extant (still living, opposite of extinct) lizard today, the Komodo dragon, is a member of this family, as is Megalania (often referred to as Varanus prisca), the largest known lizard ever to have existed.  Let's learn a bit more about these interesting reptiles!

According to a paper by American biologist Eric Pianka (link included in References section), the monitor lizards as a group are thought to have evolved on the continent of Laurasia (see map below) earlier than 65 million years ago (MYA), before even the dinosaurs died out.  After evolving in Laurasia, they then dispersed into the continents of Africa and Australia.  As of the writing of his paper, 44 species of monitor lizard are around today, with around 27 of these native to Australia, where the highest species density of monitor lizards are.  In the tropics of northern Australia, up to ten species of Varanus can reside together!

There are numerous families related to the monitor lizards within the superfamily Varanoidea, both living and dead, such as the earless monitor lizard, the sole member of the family Lanthanotidae.  The other extant family within the superfamily Varanoidea is the family Helodermatidae, which includes the beaded lizards and the Gila monster from southwestern North America, Mexico, and Guatemala.  However, in my opinion, it is the extinct family Mosasauridae that is the most interesting of the monitor lizard relatives.

The mosasaurs were the dominant marine predators throughout the Late Cretaceous Period, and were wiped out by the traumatic K/T Extinction Event, just like the dinosaurs.  Some of these mosasaurs could grow to enormous lengths, such as Tylosaurus, the apex predator of the Western Interior Seaway of North America during the Cretaceous Period.  Tylosaurus could grow to an enormous 50 or so feet long, and fossil discoveries of the stomach of this creature indicate that it fed on pretty much everything that swam in the sea: the remains of sharks, the flightless diving bird Hesperornis, fish, plesiosaurs, and even smaller mosasaurs have been found in the stomachs of Tylosaurus fossils!

The mosasaurs share something else in common with the monitor lizards: they both have a third eye on top of their head.  It's not the same as the eyes we have on our head, or even the eyes that the mosasaurs and monitor lizards have on their heads, either. A good comparison is if you close your eyes and look at a light source, and then move your hand back and forth in front of your face.  You can see something moving , right?  Just a shadow, but you can still tell that something is there.  That's kind of what the third eye of the monitor lizards and the mosasaurs is like.  If you are a baby Tylosaurus swimming in the sea and you see something pass overhead, you are going to swim to safety as fast as you possibly can: there are a lot of things in this sea that would barely noticed they swallowed you.  However, if you are a 50-foot long adult Tylosaurus and you see a shadow swim above your head, you are almost certainly going to go investigate.  Whatever it is, it's probably edible!

Another interesting thing that the mosasaurs most likely shared with the monitor lizards is their forked tongue, similar to that of snakes.  But what purpose does this forked tongue served?  Well, when the animal sticks the tongue out of its mouth, it is smelling the air.  As it draws the tongue back in, scent particles are pulled in as well.  The fork-tongued creature is able to determine which side of the forked-tongue has more scent particles on it.  If the animal was attempting to locate a dead animal or something like that, and its head was facing directly towards where the dead animal scent particles were floating from, the reptile would know that it was on the right track.  If, however, the fork-tonguer was facing due north, and the dead animal was due west of its position, when the tongue is drawn into the mouth, its owner can tell that there are more dead animal scent particles on the left side of the tongue, as opposed to the right, and now knows which way it must go to find its meal.  Pretty neat!

Can't get enough of the monitor lizards?  Well, below I have links to five videos featuring some monitor lizards (one spiny-tailed monitor, four Komodo dragon)!  Enjoy!

Spiny-Tailed Monitor Attempted Feeding

Komodo Dragon Moving Around at the Cheyenne Mountain Zoo

Komodo Dragon Relaxin' to the Maxin'

Up Close and Personal With The Komodo Dragon at the Cheyenney Mountain Zoo

Komodo Dragon Close Up at the Denver Zoo


And now, for some pictures of various monitor lizards I have taken over the years! First off is Herkemer, the resident Dumeril's Monitor Lizard at the Morrison Natural History Museum!

Next, we have a few photos that I took of one of the Komodo dragons at the Denver Zoo.

After that, we have a few Komodo dragon pics that I took at the Cheyenne Mountain Zoo!

Finally, we have a trio of pictures that I took of some tree monitors at the Cheyenne Mountain Zoo, as well!

And now, last but certainly not least, we have some pictures of some baby Komodo dragons at the Phoenix Zoo in Arizona!  They are pretty darn cute!
This was the birthday post of Gookhyun Jeong, happy birthday big guy!  And remember, if you have a birthday coming up, just email me the date at cuyvaldar123946@gmail.com with the date and your favorite animal, and I will do my best to get a post in! 

References:

http://www.conservation.org/FMG/Articles/Pages/gila_monsters_human_health_mexico.aspx

http://uts.cc.utexas.edu/~varanus/varanus.html