The Roadside Dinosaurs of Drumheller

Deep beneath the Canadian rock of Drumheller yields fascinating dinosaur fossils. The Royal Tyrrell Museum serves as a testament to that, but the town itself has embraced its love for the long-gone lizards, and so found it fitting to build dinosaur statues that can be discovered all over the town! 

It was a blast searching across the streets for these statues, and its uplifting to see dinosaurs get so much recognition. You're probably going to note that the majority of these statues are outdated, stylized, or both. Hey, we all can't get accuracy.

There were several fossil shops located around the town. The largest of them served also as a museum, but unfortunately I was not able to visit it due to time constraints. Like any dinosaur museum, of course, there were a few dinosaurs that guard the outside. In this case, slightly more realistic than the Drumheller residents, but not something a top institution would boast about. 

Looks like this Triceratops just saw Clash of the Dinosaurs for the first time...

The centerpiece of the town is this T. rex, which claims to be "The World's Largest Dinosaur" (statue). I haven't been around the world enough to check its validity, but it definitely seems like a contender. For a small fee, you can travel to the top of it until you reach the mouth. I did it several years ago. From what I remember the walls are painted with quaint dioramas of the prehistoric era.

Even the front lawns of houses are adorned with dinosaurs!

Palaeo-Editorial: Why common arguments against feathering large tyrannosaurs are flawed

This is sort of a followup to a note I made on my first post, but you don't need to see that to understand this.

Basically, there's a number of common arguments as to why feathering animals like Tyrannosaurus makes no sense, and a lot of them are logically flawed or downright incorrect. This post is to try and lay out why these are incorrect without simply saying they are.

First off, the most common reason;

"They were too big to have feathers, it'd make them overheat!"

This is particularly weird, as it's often paired with comparisons to modern-day elephants and rhinos, which immediately brings up a glaring flaw; the animals have nothing in common in terms of body shape. Elephants have a highly-concentrated surface area; this is because...well, they're basically giant squares on legs. They're thick and dense as well as big, which is why they reduced their integument. Same applies to the rhinoceros; it's a walking rectangle, essentially.

By contrast, Tyrannosaurus had a much higher surface area because of it's large, long tail, meaning it has less to worry about when it comes to heat. Also, feathers have been proven multiple times to be a better thermoregulatory structure than hair, so the comparison fails in that regard, too. Even if they didn't have any feathers (which is unlikely), they'd be looking more like plucked chicken than an elephant's hide.

Above: What a featherless Tyrannosaurus would more likely look like. Not exactly scarier, is it?

 
Basically, DO NOT USE LARGE MAMMALS FOR YOUR DINOSAUR THERMOREGULATORY COMPARISONS. THIS IS A BAD IDEA AND IT'S INACCURATE. Mammals and dinosaurs have extremely different thermoregulatory systems, so comparing them directly is not accurate. A more logical comparison would be crocodilians and birds, both being the closest living relatives to any dinosaur. However, birds are preferable to crocodiles; as they are closer in niche to most dinosaurs.

....ahem. Anyways, onto the next point!

         "Feathers are lame, I don't see birds as being scary!"

Nope, not scary. Totally not scary at all. (Credit goes to FredtheDinosaurman on DeviantArt for this lovely image!)

I've always seen this argument as particularly dumb, as it's entirely bias. Feathers do not make something less scary, that's just flat-out idiotic. It's like if I said grizzly bears were dumb because they were all poofy and not naked, slimmed-down beasts when one came barreling towards me. You aren't going to give a crap about what the T.rex bearing down on you is covered in, you're going to run like hell regardless because it's A GIANT ANIMAL TRYING TO EAT YOU. That's natural instinct.

Besides, who says everything predatory has to be scary? Look at how popular the potoo has gotten, and it's a predator who look like THIS;

This is the face of a real American hero. Just without the Texas government sort of erupting from it's brain like a horrific tumor. (Thanks to GravityKitty on imgur for the image!)

That's the opposite of scary, and yet people love it anyways; so why are people so adamant about not feathering tyrannosaurs? Well, there's another reason that comes up a lot for that...

Science ruined dinosaurs! First they say Brontosaurus and Triceratops don't exist, now they're trying to destroy the awesome theropods!

First, you're actually wrong about Brontosaurus not existing, and Triceratops was never in danger of being sunk into another genus (Torosaurus was the one proposed to be sunk into Triceratops), and second of all, there's no reason everything needs to look awesome to be awesome. This is commonly known as the "awesomebro" argument, as it entirely hinges on the idea that dinosaurs need to look scary to sell; an idea unfortunately regurgitated by Hollywood. This is, of course, a dumb argument that hinges on opinion, but the real kicker is saying that featherless theropods aren't awesome.

Fun fact; a featherless Velociraptor can't climb a vertical wall. A featherless Velociraptor doesn't have the ability to use Raptor Prey Restraint and eat it's prey alive. These are all awesome traits that the leathery raptors of the early 1990's simply cannot physically do, but modern feathered ones can. We've only made even more awesome discoveries about dromaeosaurs once we figured out they were all feathered. Sure, they aren't popping open doors to devour screaming children, but the idea of a Utahraptor climbing a tree by simply walking up it and flapping it's wings is even scarier...especially once you take into the account the fact that dromaeosaurs were no slouches in the bite department; in fact, the eponymous genus of the family, Dromaeosaurus, has a very reduced "sickle" claw and instead has very robust jaws, suggesting that it was not using RPR as much as other dromaeosaurs, and instead just used it's powerful jaws to kill it's prey by snapping their necks or skulls.

But honestly, Tyrannosaurus ripping the heads of Triceratops corpses off is awesome, no matter what integument it's covered in. Awesomeness is subjective, anyways, so this is also an opinion-based argument.

But this only really brings up an important flaw; the public perception of dinosaurs. The media does little to help, but when what Joe Shmoe thinks is over a decade behind what the scientists know, that isn't just being inaccurate anymore; that's closer to misinformation.

We're hitting what many people are calling the "Soft Dinosaur Renaissance"; a point in which many fossil discoveries completely change the way we look at dinosaurs. First it was colors in feathered dinosaurs, then it was feathery tyrannosaurs that were 30 feet long, then it was dodo-like dromaeosaurs, then it was herbivorous tetanurans, then it was bat-winged dinosaurs. Keep in mind, all of these were found in the last 6 years! These animals are the sort of things that Dougal Dixon would have thought up in his lunch break, but they're quite real, and definitely prove dinosaurs were, and indeed still are, an enormously strange group of animals.

And honestly, isn't oddity so much more engaging than yet another cheap scare? We're naturally drawn to the bizarre and strange; it's why cryptozoology is such an easy field to enter. So if we like the unusual, why is it that people are against feathered tyrannosaurs?

Because people also like their childhoods. This is the same idea as what causes, say, a Transformers fan to cry "Ruined FOREVER!" when they sees something they don't like in the franchise; they're attached to their childhood nostalgia and don't want it to be "replaced". Same thing with feathered dinosaurs; people don't want feathered dinosaurs to "replace" the scaly ones they were fond of, and so they adamantly try to defend their nostalgia. However, their fight may be futile; as future generations become more exposed to feathered dinosaurs, that view will become the new "normal", and scaly theropods become the new tripodal theropods. This is inevitable as long as children are exposed to feathered dinosaurs in media.

Complaining does absolutely nothing, because science has already heard your complaints; and it doesn't care. As an ever-evolving medium, science cannot backtrack to when convenient. And it is no longer convenient to backtrack to the early 1990's.

Happy 110th Birthday, T. rex!

Cast of Tyrannosaurus rex "Stan"
Photo by the author, courtesy Natural History Museum of Los Angeles County

In 1892, American Paleontologist Edward Drinker Cope discovered the remains of what was then the largest predatory dinosaur ever known. It was not until a decade and three years later, on October 2nd, that the dinosaur would be properly described and be given the fear-inducing name that has been etched into the minds of every four-year old: Tyrannosaurus rex. The tyrant lizard king. Just one look at the creature is enough to convey images of a bloodthirsty monster chasing down terrified prey. 

Of course, since then, our knowledge of the "King of the Dinosaurs," has drastically improved. Like most large predators, it hunted only when need be, and preferred meals that didn't fight back - carcasses. Numerous discoveries paint a complex family tree, which include lookalikes like Albertosaurus, and lesser known theropods such as Stokesosaurus. From other tyrannosaurids and tyrannosauroids can we deduct what the lifestyle of such a fearsome creature was like. Albertosaurus and Daspletosaurus bonebeds point to a more social lifestyle for T. rex - was it possible the tyrant king lived in families, using numbers to take down Trikes and duckbill dinosaurs? More recent discoveries suggest Tyrannosaurus was covered in a feathery down. It's a heated debate that remains unresolved, but such questions are what Paleontologists crave for.

Dinosaur Paleobiology - Speculative image of Tyrannosaurus hunting in gangs to bring down a Triceratops
Image Credit: Gregory S Paul

Many question the time spent studying T. rex. Besides Coelophysis, no theropod dinosaur has been as well researched. Heavyweights Spinosaurus, Carcharodontosaurus, Giganotosaurus, and possible Mapusaurus have claimed the title of biggest land carnivore ever, a title previously held for more than 50 years by T. rex. Ultimately, however, Tyrannosaurus represents more than an over-studied rock. For many, including me, T. rex is a reminder of a childhood much like the Cretaceous in that it is lost forever in time. The dinosaur lures the enthusiasts into the exciting world of Paleontology. Most importantly, T. rex serves as an inspiration for young minds all around the globe to contribute to science. And that is why Mr. rex will hold a special place in my heart unlike any other dinosaur. 

Happy 110th birthday, T. rex!

CM 9380 - The holotype specimen of Tyrannosaurus rex
Image credit: Thomas Holtz Jr.

Another Dinosaur Field Guide!?

The date: September 12, 2015. The place: Barnes & Noble. It was another ordinary day of browsing the science section in hopes of finding new books. Fortunately, I sacrificed time and took the initiative to take an extra-long drive to a Barnes & Noble I usually don't frequent. Lo and behold, their Paleontology section had other books besides Dinosaurs: The Grand Tour and DK's Prehistoric Life!  Of most interest to me was A Field Guide to Dinosaurs of North America (And Prehistoric Megafauna), written by Bob Strauss. 

First, a little information about the author. Quoting the back cover, "Bob Strauss is the author of two best-selling question-and-answer books that range across the expanse of science, biology, history and culture: The Big Book of What, How and Why (Main Street, 2005) and Who Knew? Hundreds & Hundreds of Questions & Answers for Curious Minds (Sterling Innovation, 2007)." It also goes on to say that Strauss is the "dino-expert" for About.com. I haven't visited that site in awhile now, so I can't vouch for accuracy/reliability, but I encourage readers to see for themselves how much credibility it establishes Strauss. 

In my last book review, I covered Henry Gee's A Field Guide to Dinosaurs (read it here), and so I'll address the big question, "What are the differences between both books?" Aside from the obvious stuff, like different authors and illustrators, Strauss' book provides actual, factual information in each dinosaur profile, making for much less speculating on his part, but more for the reader, who must separate fact from fiction. Additionally, Strauss takes a more humorous tone on the subject matter, much like Robert Mash's book, How to Keep Dinosaurs. Finally, Strauss covers other prehistoric fauna, and not just the dinosaurs. More on that later.

As far as the writing goes, it's standard. There's plenty of comical scenarios Strauss manages to express vividly, such as how an Albertosaurus ambush would go down. It's a controversial opinion, but I believe that his attempts to bring scientific info into the writing downplays the potential he had. The idea itself is fine, but the execution is sub-par. It's the same old information that many, many other dinosaur books have stated. And some of it is just plain wrong. Note to the author: Acrocanthosaurus and Spinosaurus were NOT "closely" related (think of it this way, you wouldn't call a dog and a manatee "closely" related). Same physical features =/= closely related. It's clear that Strauss is an enthusiast, and not a scientist. What I did like, though, was the 40+ prelude. Strauss explains the inaccuracy of movies and even nature documentaries (you know those awesome documentaries you watched as a kid that had clips of harpy eagles swooping down and carrying off lion cubs? Fake. Did ya really think the camera happened to be rolling at the right place, at the right time?), and how it has created a severe misrepresentation of dinosaurs. The fact of the matter is, dinosaurs are animals, not monsters, and nine times out of ten, predator vs prey engagements end without any blood shed. I'd have to agree, and Strauss does a superb job describing the problem. My favorite quote, "If you're going to take a dinosaur trip to purely watch monsters fighting, be kind to yourself, go to your man cave, and watch an episode of Jurassic Fight Club instead." Brilliant.

Bistahieversor 

Each illustration is provided by Sergey Krasovisky, a rather underrated paleo-artist. Oddly, they decided to use his older work. Most of the ornithischian dinosaurs are drawn fairly accurate (he gets ceratopsid feet right!), save for a few hadrosaurs in the classic tail-dragging pose, but theropods don't get it as easy. A bulk of them are depicted with "bunny-hands," and those that should be feathered like Utahraptor, are not. The biggest problem? It contradicts Strauss' writing. The worst offender being Strauss spending an entire paragraph chastising Jurassic Park for having over-exaggerated, "lizards adorned with green scales instead of feathers" (direct quote) when describing Deinonychus, only for the illustration to be... a featherless raptor with green scales. Yup. I'm not kidding. (Even Krasovisky calls it a retro depiction on his DeviantArt! I know for a fact he has a newer, albeit under-feathered restoration of Deinonychus) A bit disappointing to see that they opted not to use Krasovisky's beautiful action shots, too. 

A happy looking Euoplocephalus

Prehistoric fauna such as Dimetrodon and Smilodon are given some of the spotlight. It's nice to see non-dinosaurs, but what was the point? It would make sense if a lot more non-dinosaurs were featured, but as is, they only make up 5-10% of the book. It just feels bizarre to throw in a few random mammoths in your dinosaur book; it just causes more confusion.

There's a pretty big flaw, and it's the price. For what it is, it's not cheap. Retail price goes for 22.95 US dollars. Essentially, what you're getting is a mini dinosaur encyclopedia with less writing than what looks say (the font is fairly large, and most profiles are two-pages long). The illustrations are nothing special. No landscapes. No action shots. At most, I'd think this should go for $15.

Verdict

As a humorous book, it is a good read. Unfortunately, readers will learn very little from Strauss' book, and more often than not, will notice very obvious inaccuracies.If you're going to buy it, just remember that it most likely will not prove a reliable source. At least it covers its material far better than How to Keep Dinosaurs did.

Royal Tyrrell Museum: The Mammal Hall

The final epoch in the geologic time scale, the Tertiary period saw the rise of our ancestors, the mammals. It's often overlooked by the previous era, and I'll be one to admit that my knowledge on the Cenozoic isn't quite as "up-to-date" as it is on the Paleozoic and Mesozoic. Nonetheless, Cenozoic era animals are as equally interesting as any dinosaur...

...Such as this Pliohippus. 

As you've probably guessed by now, Pliohippus was a close relative of the modern horse. Now for something a little more bizarre, Uintatherium! Life-sized, too!

What a skull! It's no surprise Entelodonts are nicknamed "terminator pigs." 

Two Megacerops (Brontotherium) locked in combat.

The grand display is the mount of a Woolly Mammoth, defending itself from an onslaught of Smilodon. The sense of scale it conveys is impressive, and there's a moment where it feels like you're actually there.

There's a scale that lets you find out how your weight compares to modern mammals. I managed to be as heavy as a deer (150 lbs). Maybe I ought to go on a diet!

In total, the museum took about three hours to tour thoroughly. The Royal Tyrrell Museum has remained a major research center for paleontology, and justifiably so. If you plan a trip to Alberta, or already live in the area, I highly recommend taking a visit. Even the trip there is worth it (which I will be covering in a later post)!

Review: A Field Guide to Dinosaurs

Paleo-fiction that aims to create interpretations of the Mesozoic world are, surprisingly, quite rare to find. It's always a treat when a daring author decides to bring something to the table. In this case, paleontologist/science writer Henry Gee, along with inventive paleoartist Luis Rey, have delivered a dazzling "new" (quite old by the time of this review) book, A Field Guide to Dinosaurs. The result is more than satisfactory.

Main cover. 

The most important thing to remember in regards to this book is that it is a work of fiction. Of course, what's science-fiction without factual elements? Quoting Gee, "All good fiction is enriched by factual research, and we have used the latest paleontological findings as jumping-off points for speculations that are (we hope) sufficiently plausible to convey the experience of dinosaurs as flesh and blood creatures." With all that being said, the introduction does give a basic summary of the science behind paleontology; it is both informative and perfect for the beginner dinosaur-enthusiast.

Once the reader reaches the dinosaur profiles does it become apparent that the field guide is purely fictional. There's dozens of speculations about each dinosaur, and I absolutely love it. A fair share of them are based on actual paleontological theories - such as Zuniceratops being depicted as an opportunistic omnivore, scavenging dinosaur carcasses if need be (based on the idea that ceratopsians sported beaks developed for snapping meat off bones). Most are based on behavioral attributes with modern fauna. For example, Muttaburasaurus is said to have bitten the legs off pterosaur chicks as a way to gain calcium. The thought of it is grotesque, but deer today have been observed devouring birds, making the theory a bit less far-fetched then it initially appeared.

Sexual dimorphism in theropods? One of the many questions raised by Gee.

A majority of the illustrations provided in the book are pencil sketches (by Luis Rey), much like a real field guide. The pencil sketches offer great drawing references, adding another reason one should be encouraged to pick up this book. I know I have benefited greatly from the drawings.

The artist, Luis Rey, has garnered a big reputation in the paleo-community; mostly positive, though some negative. His more recent digital illustrations seem a little sub-par then what we've been used to, but fret not! For many of his older illustrations have been chosen for the book.

Two Lilensternus harass a Scelidosaurus (misidentified as a Scutellosaurus - which in reality was a small, bipedal armored dinosaur from Arizona)

There are plenty of full-color illustrations as well. Many are from Thomas Holtz's Dinosaur Encyclopedia, published in 2007, which may be a slight turnoff for those who already have Holtz's book.

Eoraptor (the image is included in Holtz's book as well)

Ceratosaurus - I suspect that this image was created for the publication of this book, as it seems unfamiliar

Quite possibly, one of the greatest benefits the book has are the dinosaur skeletals included on every page. One would think a dinosaur book should have skeleton illustrations, yet it's astonishing to see that so many don't. 

Skeletals for Tyrannosaurus and Brachiosaurus, respectively 

Verdict:

 It's books like these that show the world's appetite for dinosaurs. Being able to take scientific information, and to use it to create entertaining and unique speculations draw in enthusiastic readers. A Field Guide to Dinosaurs does exactly that; achieving its goal of being a text version of  Walking With Dinosaurs. Even better, it is able to make the distinction between fact and fiction. At 24.99$ US dollars, (it is almost certain you can get it cheaper) it's worth every penny.

Palaeo-Study: What's with all these feathery theropods?

((Author's Note: As my debut post here, I'd like to make my own little series called Palaeo-Study; where I will discuss more serious topics that wouldn't fit into a Paleo Profile, but deserve their own posts. As such, this is not going to be a short post. Enjoy!
~Raptormimus))

As many are likely aware, palaeontologists have considered birds to be direct descendants of the theropods for a very, very long time. This is, obviously, because of the taxon known as Archaeopteryx ("first wing"), which was first described in 1861 by Christian Erich Hermann von Meyer.

Archaeopteryx reconstruction showing what we know about the animal.
Credit for the image goes to Nobu Tamura.

This small dinosaur has caused a bit of a cladistic controversy for decades; palaeontologists have been split on if it was a true avian, albeit the most primitive of them, or if it was a highly bird-like maniraptoran. Currently, consensus seems to be on the former, though it remains under debate.
The genus has also played a pivotal role in solidifying the concept of evolution as the palaeontological consensus; as it has both features of more advanced true birds (pennaceous feathers and a mostly-feathered body) and traits of non-avian maniraptorans (teeth, clawed fingers).

However, for as pivotal as this genus is, this also means that it has caused a fair bit of controversy, especially for those who do not believe in abiogenesis or evolution as the origin of life. An animal with traits of two types that these people distinctly separate disrupts their faith; and they either say it's a bird and nothing more or, in more extreme cases, call it a hoax fossil (likely in reference to the actual hoax fossil that was called "Archaeoraptor"). There are multiple factors that separate the two, however;

• Archaeopteryx was found in Germany, while "Archaeoraptor" was found in China, a location known for it's instances of bootleg or faked fossils.
• Archaeopteryx is known from multiple well-preserved specimens that clearly could not have been Frankensteined together. "Archaeoraptor" was made of multiple, quite damaged specimens that looked as if they were patched together.
• Archaeopteryx was Late Jurassic, while "Archaeoraptor" is just an assortment of Cretaceous animals stitched together.

As for other feathery theropods, ones that people often bemoan and ridicule are Velociraptor and Tyrannosaurus; both due to bias. Feathers get commonly associated with things like chickens, which are considered derpy, stupid meals on legs. Meanwhile, scales get associated with dragons, which are seen as awesome, powerful beasts. The comparisons are unfair, obviously; why compare a mild bird like a chicken to a powerful monster like a dragon?

Again, the answer is bias; people want to "show" how ridiculous feathers on dinosaurs are, and so say that it makes them look like giant chickens instead of badass prehistoric dragons. But this isn't the case; a fully feathered Tyrannosaurus running at you is always going to be just as scary as a scaly one doing the same, because while we may say we have a preference, the fact is that our instinct will tell us what to do regardless of the animal's integument. This is also why people find bears scary when one runs at them, but not when looking at photos; it's the fight-or-flight response in action.

A good example of this sort of mental conditioning is Jaws, and the impact it had on sharks in the public eye. Jaws was a masterful horror movie, but it inadvertently caused a wave of fear-mongering that has yet to subside, and caused many to vilify sharks. The same is, in some manner, true in this instance; people fear-monger that feathered dinosaurs look "stupid" and "not scary", and thus they aren't immediately profitable, so movies don't make them look cool and scary, rinse and repeat ad infinum. 

To put it another way...if it was actually happening to you, you wouldn't care about how feathered-up that T.rex was, you'd just want to get as far away from it as possible. Feathers are not inherently "less scary" than scales; it's just people are conditioned to think they are. Popular culture certainly doesn't help the image, either; when what Hollywood considers "good" is a good 5-10 years behind what we'd find acceptable, that poses a big problem to scientific accuracy (then again, nobody in Hollywood seems to give a brontosaur's backside about that anyways... :p). 

In terms of phylogeny, we know 100% that most all coelurosaurian theropods had some amount of feathering. How extensive it was varies, but all known coelurosaurs have feathers; this is undeniable fact. For example, we know Velociraptor had pennaceous feathers on it's arms (that is, arms with a central shaft, like birds) due to quill knobs left on the forearm of specimens, was but the size of an ocelot...and was, to be blunt, quite stupid and couldn't run fast at all; but of course, popular culture would have you think they were leathery, lightning-quick, man-sized superpredators smarter than whales, dolphins and some primates. And that's not even getting into the other issues that movie has.

All coelurosaurs, including tyrannosaurs, had feathers. This is not for debate, it's pretty much confirmed at this point. Technically, feathers may spread back into the base of Archosauria (or at least Avemetatarsalia), as modern alligators carry the base genetics for creating feathers in their DNA, just rendering them into scutes instead. This suggests feathers (or at least some kind of filamentous structure) are a basal archosaur trait, and that crocodylians shed them (turned off the gene) as they became more adapted to a semi-aquatic lifestyle, and likely closes the notion that the two structures are separate genes. In essence, crocodile scales....are really very primitive forms of feather.

So really, this could just mean all dinosaurs have the possibility of possessing feathers, as they would all have to have beta-keratin. If they did is uncertain, that they could is. And it's not like feathers are detrimental; after all, feathers give our fine dromaeosaur friend the power to run up walls and lets him pin his prey and eat it alive; surely, those can't be considered "weak" and "dumb" abilities?
So chin up about Velociraptor being enfluffled! It just makes it so that you literally have no escape from it other than shooting the darn thing.

Or running quickly.

Either way, it's more dangerous than the roid-rage super raptors we see in pop culture in terms of terrain adaptability. Not even the walls are safe!

Editors' note: It is important to remember that rarely anything in the field of Paleontology can be considered absolute. Velociraptor was almost certainly feathered, but the debate whether or not T. rex was remains controversial. For evidence in favor of scaled tyrannosaurs, refer to here (check under 'Yutyrannus the tyrannosaur?' and 'The Feather Scale Dichotomy')  -http://reptilis.net/2012/07/23/feathers-on-the-big-feathers-on-the-small-but-feathers-for-dinosaurs-one-and-all/

Author's reply: While it's certainly plausible that more advanced tyrannosaurids did undergo some amount of feather reduction, the benefits of feathers in a thermophysical sense is too much to suggest that all or even most of their feathers became reticulae. The most accurate conservative depiction of the genus is the newly revamped design in use by the game Saurian, which can be seen here.

However, evidence is leaning towards a subtropical climate for Hell Creek, and an average temperature not that far from the Yixian's, which may suggest that either Hell Creek had a consistent cold period or that it was overall cooler than we've predicted. Even if it was subtropical, more feathers on the animal make it more effective at thermoregulation than an unfeathered animal. I may decide to make a post showing how common arguments for naked tyrannosaurs are flawed sometime in the near future.

Introducing...COELOPHYSIS!

Dinosauria would like to welcome our newest writer, Justin Banner! Take it away, Justin!

Hello, fellow dinosaur fans! I'm Coelophysis here. I was mentioned in a post regarding paleoart here under my real name, Justin Banner. I am proud to say I am now a proud part of the Dinosauria family here, alongside RaptorRex.

As an avid paleontology enthusiast and unprofessional paleoartist, I feel the need to enlighten you with as much Dinosaur-related stuff as I can. So I hope you all enjoy my being here, and my up-and-coming contributions to this blog.

Cheers!

- Coelophysis

Paleo-Profiles: Albertosaurus/Gorgosaurus

Author's note: Raptorrex here, thought I'd try something new out. Basically, Paleo-Profiles are biographies of prehistoric animals. More often than not, the animal addressed correlates to the previous post. Example: If I were to review a book about Tyrannosaurus, then the Paleo-Profile would be T. rex. The main goal of this project is to give information for school projects and such. Expect these to come once a month. 

Albertosaurus

Image Credit: Luis Rey

 Name: Albertosaurus 

Species: A. sarcophagus

Discovery: Osborn, 1905

Geologic era: Campanian of the Late Cretaceous

Geographic area: Canada/USA

Family: Tyrannosauridae of the suborder theropoda

Name: Gorgosaurus

Species: G. libratus

Discovery: Lambe, 1914

Geologic era: Campanian of the Late Cretaceous

Geographic area: Canada/USA

Family: Tyrannosauridae of the suborder theropoda

Albertosaurus, one of the best-studied tyrannosaurids to date, lived during the Late Cretaceous of North America, with a habitat ranging from Alaska all the way down to Texas. Like most other tyrannosaurs of its time, Albertosaurus is characterized by a sleek build, triangular horns above its eyes, and remarkably short arms. Based on current fossil evidence, we know that Albertosaurus (as well as Gorgosaurus) was a particularly common predator during its time. In Alberta, Canada, the Dry Island bonebed has allowed paleontologists to uncover more than 25 different individuals of varying age. Not only have the findings shown that Albertosaurus populations were abundant, it has also been a revolutionary change in the way tyrannosaur behavior has been proposed. The idea of tyrannosaurs living and hunting in packs was first hypothesized by Dr. Gregory S Paul in his book Predatory Dinosaurs of the World, alluding to the behavior of the big cats today. Actual fossil evidence for this hypothesis would be found in the late 90's by a team led by Dr. Philip Currie of the Royal Tyrrell Museum. At the very least, Albertosaurus lived in small families, possibly to protect their young.

Gorgosaurus (bottom) and Albertosaurus (top)

Image credit: Fabio Pastori

Gorgosaurus was discovered a little less than a decade after Albertosaurus, again, in Alberta. Gorgosaurus follows the same body structure of other tyrannosaurids, though the eye sockets are rounder on Gorgosaurus than that of other tyrannosaurids. Like its larger contemporary cousin, Gorgosaurus is extremely well-studied, with multiple specimens having been found. Skin impressions belonging to Gorgosaurus show a texture like that of modern birds. Although no evidence of feathers have been found, it is assumed that Gorgosaurus was covered in plumage in at least one growth stage. 

Gorgosaurus did not live a happy life. Many specimens are adorned with injuries such as infections and fractures. A pathological study on Gorgosaurus specimen TMP94.12.602 reveals a fracture in the right fibula's shaft, as well as rib fractures and bite lesions on the skull. All the wounds were shown to be healing.

Gorgosaurus

Image credit: Natural History Museum of London

It's been long debated whether or not Gorgosaurus can be considered the same genus as Albertosaurus. Before, it was commonly accepted to lump the two into the same genus, though more recent studies show otherwise. Skull anatomy of Albertosaurus is more similar to that of Daspletosaurus, another contemporary tyrannosaurid, and Tyrannosaurus than it is to Gorgosaurus. Albertosaurus also has proportionately smaller fore limbs. To quote Dr. Currie, "[Albertosaurus and Gorgosaurus] were no more similar than Daspletosaurus and Tyrannosaurus [were]." For now, unless new research pops up, Albertosaurus and Gorgosaurus can be regarded as different genera.

The tropical ecosystem of Cretaceous Alberta was teeming with life. Albertosaurus and Gorgosaurus not only lived alongside each other, but as well as a another tyrannosaurid, Daspletosaurus. The more slender build of Albertosaurus and Gorgosaurus suggests that they were better suited to hunting hadrosaurids, while Daspletosaurus tackled armored prey. Hadrosaurids such as Parasaurolophus, Lambeosaurus, and Corythosaurus were most certainly abundant during the time. With the disappearance of most sauropods, the "duck-billed" dinosaurs had relatively low competition for food. Ceratopsians, the horned dinosaurs, were another relatively common dinosaur at the time. Pachyrhinosaurus, Chasmosaurus, Spinops, and Styracosaurus were some, but not all, of the ceratopsians to have lived with the tyrannosaurs. Among them were ankylosaurs such as Euoplocephalus, filling in an ecological niche the stegosaurs of the Jurassic Period left behind. Smaller predators like the ornithomimosaur Struthiomimus and the dromaeosaur Dromaeosaurus hunted smaller prey. Champsosaurus, a relative of the modern-day gharial, populated lakes and rivers. Overall, a lush and tropical climate allowed for an extremely diverse ecosystem of many different organisms.

Gorgosaurus libratus -  Called the 'opisthotonic' pose, caused by contraction of neck muscles during/after death

Photo by the author

References/Further Reading

"Royal Tyrrell Museum." Royal Tyrrell Museum. N.p., n.d. Web. 18 Aug. 2015.

Mccord, Robert. "Arizona Museum of Natural History." Arizona Museum of Natural History. N.p., n.d. Web. 18 Aug. 2015.

Switek, Brian, and Julius Csotonyi. Prehistoric Predators. N.p.: n.p., n.d. Print.

Palmer, Douglas, Simon Lamb, Angeles Gavira Guerrero, and Peter Frances. Prehistoric Life:. New York, NY: DK Pub., 2009. Print.

Benton, M. J. Walking with Dinosaurs: Fascinating Facts. New York: Dorling Kindersley Pub., 2000. Print.

Pim, Keiron. Dinosaurs the Grand Tour: Everything worth Knowing about Dinosaurs from Aardonyx to Zuniceratops. N.p.: n.p., n.d. Print.

Paul, Gregory S. Predatory Dinosaurs of the World: A Complete Illustrated Guide. New York: Simon and Schuster, 1988. Print.

Museum Visits: Royal Tyrrell Museum Part 3

For a dinosaur enthusiast, there's little that can make one geek out as much as the Royal Tyrrell Museum's Dinosaur Hall can. Filled to the brim with replica casts and real fossil specimens, its enough to make the most hardcore dino fan look around with sheer awe.

The Late Jurassic Camarasaurus, from the Morrison Formation, is the first attraction in the Dinosaur Hall. 

Head over to the right of the Camarasaurus and visitors can find an Allosaurus with its latest meal, an unfortunate Camptosaurus. A Stegosaurus (albeit in an outdated "retro" pose) watches the vicious attack.

Not surprisingly, the bulk of the dinosaur that make up the exhibit hail from the Cretaceous era, such as this Gorgosaurus (right) and Euoplocephalus (left). As an avid ankylosaur lover, the Euoplocephalus mount looks absolutely gorgeous. It's a bit of a shame most ankyosaur remains are, for the most part, incomplete.

Gorgosaurus makes another appearance, this time scavenging the carcass of a Centrosaurus. The diorama represents the famous bone bed discovered in Alberta containing at least 200 Centrosaurus remains. Whether or not it was a flash flood that killed the ceratopsians, it's certain that theropods and other carnivores would have scavenged the bodies.

Remarkably well-preserved fossils of Pachyrhinosaurus.

Psittacosaurus lived in Mongolia and is considered one of the earliest known ceratopsians. Lack of facial horns and a bipedal stance certainly don't make it look like Triceratops, but it matches other primitive ceratopsians like Aquillops.

Chasmosaurus, like Pachyrhinosaurus and Centrosaurus,lived in Alberta and were most likely a substantial prey item for tyrannosaurs like Gorgosaurus and Albertosaurus.

Hadrosaurs were abundant during the Cretaceous, Canada especially. Pictured are Lambeosaurus (above) and Gryposaurus (below).

A collection of hadrosaur skulls.

Ornithomimus attempts to make off with Maiasaura eggs.

Back near the Gorgosaurus mount you can find several Dromaeosaurus.

The museum even has a marine exhibit! Mosasaurs, plesiosaurs, pliosaurus, the exhibit showcases what life would been like in the Western Interior Seaway.

The Maastrichtian Cretaceous is our final stop in the Mesozoic era, and the familiar three-horned face finally appears! Triceratops was, you guessed it, one of the very last dinosaurs to live during the Cretaceous.

Hypacrosaurus, the near the highest lizard (that's what its name means! It was almost as tall as Tyrannosaurus).

Tyrannosaurus claims its position as king in the hall, looming gleefully over every other dinosaur. This specific mount is pretty notable for appearing in that old IMAX film T. rex: Back to the Cretaceous

A close-up of the tyrant king's skull.

There's only one more exhibit after the dinosaur hall, and its the Age of Mammals. Next time, we'll visit our modern ancestors in the Tertiary era!