Saturday, November 7, 2009

Contemplating the Functional Morphology In Vertebrates and the Latest Research

While off-line and continuing my "Paleo Quest" in between tweets and posts, I continued my research, when I could, through browsing the internet and watching some entertaining and enlightening documentaries which cover the latest research in Paleontology. Doing so, I managed to see two documentaries on NatGeo and one on PBS (KET here in Kentucky.). The two documentaries on NatGeo are entitled "Bizarre Dinosaurs," which is a documentary based off the National Geographic article of the same name, and "Dinosaurs Decoded," which explains Horner and his colleague from Berkeley, Mark Goodwin's theories that, if they hold true, then approximately 1/3 of all Dinosaur taxa would be wiped out! In other words, 1/3 of these species do not exist!! This is a case of Mistaken Identitiy, they claim. I'll get to these in a second. The PBS program was the first of a three-part miniseries of episodes on their successful show Nova, entitled "Becoming Human," which includes the latest fossil finds and knowledge about Human evolution, as well as Chimpanzee and Human divergence. However, this post is about functional Morphology in Vertebrates (in other words, body plan/ Anatomy) , more specifically the Dinosauria. In this case, this would include the two National Geographic documentaries I mentioned.

The nice thing about these two documentaries is their extensive coverage of the group, including the odds and ends, as well their use of Diagrams and Models in addition to interviews with key experts, like Dr. Horner, Dr. Sereno, Dr. Bakker, Dr. Holtz, Dr. Witmer, among others. Now, lets go throught the oddities of the documentaries one by one.


"Bizarre Dinosaurs"

The name says it all and it nicely covers the some of the odd ones of the Dinosaur World. The following list are of the Animals covered in the documentary and what they said about them:

  • Amargasaurus- this sauropod is truly bizarre with it being the only sauropod/titanosaur genus to have a double row of elongated "spines" on it's back, large enough to have supported a skin sail, similar to the Spinosaurus aegyptiacus.
  • S. aegyptiacus- I found this part to be the most interesting as not only did the show talk about the basics of this animal, but commented on it's truly bizarre morphology, the crocidilian snout and the large single row of spines jutting from the middle vertebrae of the spinal column, which most likely supported a sail as well. Oddly enough, Horner admitted to the true diet of this theropod, when they referrenced it's appearance in the failure, Jurassic Park III. His reasoning for selecting the Spino and not, say...Giganotosaurus carolinii or T. rex, yet again, was, one, it was the largest theropod known, and second was he was tired of T. rex "hogging the glory." They, then, commented on it's bizarre "sail." Covered were the ideas of thermal regulation while fishing, and/or display.
  • Nigersaurus- "The Jurassic Lawn Mower/ Vaccuum cleaner" as I'd like to call him. This sauropods most bizarre feature is it's head! Clearly this looks like it's the offspring of a Diplodocus and a vaccuum cleaner, making me infer it's a diplodocid. The teeth and the jaws of this animal or in such a bizarre layout that it possibly combed the low growing vegetation.
  • Dracorex hogwartsia- or "juvenile Pachy." This pachycephalosaurid is so named because it looks like something out of a fantasy film, specifically a dragon. The odd skull doesn't seem to be real! Well it is, but what exactly is it? "Hogwarts' Dragon King" is one of those taxa that Horner and Goodwin believe to be a stage in the life of a related pachy. So, is it's own species/genus or is it the growth stage of another animal. (Will cover this soon....)
  • Deinocheirus- Bizarre as it only known from a gargantuan pair of menacing arms and that is it!! Ornithomimid? Herbiverous? Carniverous? Omniverous? We don't know! This theropod is about as mysterious it gets!
  • Epidendrosaurus- Tiny, cute, but bizarre! This little theropod, and I Do Mean Little, is bizarre as it apparently had large eyes, making it nocturnal, and an elongated index finger, possibly to fish for insects in the barks of trees.
  • Masiakasaurus- This small theropod is bizarre, though sadly not in the documentary, but the article, was bizarre in that it had it's four front dagger-shaped teeth curved out of it's mouth and looked like hooks at the end of it's jaws.
  • Carnotaurus sastrei- This large Cretaceous theropod is bizarre for it's bull-like face, from which it gets it's name. The function of the horns was purely social and used for display and identification between members of the family. It was portrayed in Michael Crichton's The Lost World as possessing the ability to blend into it's environment like a chameleon.
As you can see, they're all pretty bizarre. The next documentary I'll mention in this lengthy post is "Dinosaurs Decoded." This documentary covered the research published in the journal PLos One. And, as stated above, according to these findings on Dinosaur growth patterns and how their morphology changed as they grew and matured. Fragmentary bone, once thought to belong to a pachycephalosaur was identified by Mark Goodwin of Berkeley and collegue of Horner as a infant Triceratops. The main reasons behind a lot of these claims between the Tyrannosaurs, the Certopsians and Pachys covered in the documentary was not of whether bones in the skeleton were fused or not, as many bones in the skull of some adult species aren't fused, allowing a kinetic skull when eating (i.e. T. rex had many bones in it's skull that had not fused so that to handle struggling prey, could twist and turn and not break off it's teeth. These gaps were will with either cartilage or muscles to the skull could "flex" when the animal was eating.), ibut instead microscopic sutures that had not closed in some specimens and taxa as they would be in an adult animal. Personally, I find it quite an interesting hypothesis. This leads me back to Dracorex hogwartsia, as well as Stygimoloch, and Pachycephalosaurus.  Observing tiny slices of bone in each species has led to the finding of open sutures in Dracorex and Stygimoloch, indicating these animals were not full grown adults,but, according to Horner and Goodwin, they are merely stages of development in Pachycephalosaurus. How? What are the significance of sutures? Open sutures in the bone allow more room for the animal to grow. This has led Horner and Goodwin to apply these ideas and methods on Tyrannosaurus rex, Nanotyrannus lancensis, and other tyrannosaurs. Horner believes that the Nano may be a teenage T. rex. Is he right? Well.....there's not way for sure. However, there is a chance that the Nano may merely be a growth stage of T. rex or another tyrannosaur species.


However, there's more to growth than that. It's true that fused bones in an animal don't necessarily mean the animal is full grown. Sutures are a good way to tell, however, that doesn't necessarily mean anything either. Now, I know I'm no Ph.D, yet, but think about it. There may be some taxa that reach adulthood but continue growing through out their entire life. Therefore, they would still have open sutures. To truly tell an age and when they stopped growing when they matured is to count the growth rings as well as look for sutures under a microscope.

In my personal opinion, I agree that dinosaur juveniles and their adult counterparts were not Mesozoic "Dr Evils and Mini-Me's" of each other here. More research definitely still needs to be done.

On another note, I would like to comment on the habitual nature of Paleontologists, Biologists and Zoologists that think "black & white," if you wil about the functions of some animals with strange morphologies and appendages. A prime example are the plates of Stegosaurus. My hypothesis is that they were for sexual display, family member/sex identification and thermal regulation, along with other taxa with bizarre appandages like Spinosaurus aegyptiacus' sail and Amargasaurus. There's also the old question about the functionality of the front limbs of the tyrannosaurs. Sure, there obviously was the trade off with the larger head and more muscular neck, along with powerful jaws, and the shrinking of the seemingly vestigial fore-limbs. However, when paleontologists discuss function, they say it's "either this OR that" which is just NOT a good way to think in this field! I believe they were used in number of different ways from courtship, mating, and consuming prey. They might have even helped the animal get up in the morning or something. The arms may have been used to pick itself up if it tripped on the hunt. And, if injujured and can't hunt, the family would have taken care of the injured member. The limbs could have been used for grooming as well, as proposed by Dr. Robert T. Bakker.

My point is that the majority of paleontologists are too "black and white," if you will in their thinking, instead of "grey." In other words, they need to stop thinking that something is "either/or." The thinking is too extreme left and right wing with no middle ground. At least, that's what all this research and thinking has taught me. Hopefully, I will learn more about this when I continue my "Paleo Quest" and my own personal research in my spare time between posts and tweets.

Friday, October 30, 2009

Fossil Fact #11!!!!!!!!!!!

Hopefully, this Fact will make up for my hasty tenth Fact as I am covering a complicated topic, with my OWN personal Hypotheses based on what I've read, despite if you deem me credible or not. This time I feel as I have a bit more time on my hands and I can rest easy, but I still would like to get started. However, since this is one of the most complicated topics in Biology, I ask that you pay close attention and NO scanning. If you scan, then you will leave bewildered, so, please take your time. Let us Begin:


Extinctions- Out with the Old/ In with the New-

Please pay attention, readers, and read this Fact verbatum! For a good several centuries, Early Biologists, thought that all organisms that had ever lived on this Earth was still alive,  and no one would have thought that God would be one to let his most precious creations die off. Yet, in the late 18th Century, French Anatomist Baron Georges Cuvier (1769-1823), known by many as the Father of Modern Paleontology, proposed the idea of Extinction.

EXTINCTION?! Why in the history of the World would God kill off His own creations? The answer is known by many today as not the hand of God but Natural Selection, with the great Father taking a backseat to the Universe and intervening as He sees fit. This leads into my next topic of Discussion: "What is it?" and "How does it apply to us today?"


What IS Extinction?!

Extinction, by working scientific definition, is the absence/disappearance of all individuals of one taxa or several populations of several taxa in an ecosystem.  That's extinction, in a nutshell, however, this is still a complicated topic to instruct, so please keep reading.

What CAUSES Extinctions?

Now that we know WHAT Extinction is by working definition, we need to understand what it's role in Evolution actually is...more specifically the "Causes." Unfortunately, many scholars know WHAT it is and it's implications, but WHAT truly causes these mysterious disappearances of populations of organisms remains unknown. That's what this Fact is truly about and I've had an ambition to discuss this recently.

However, we do know that Extinctions are multi-factorial and that not ONE factor can cause extinctions as it's like a Dominoe effect, where one change affects the other factors until the group is wiped out, or at least, that's what is believed to happen, yet when it comes to large extinctions like the extinction of the Dinosaurs, the Permian extinction, and the Pleistocene extinction (A few of which I will cover briefly in a little while, if you'll bear with me.) the factors aren't as forgiving as they are with modern extinctions, thanks to the gap in the Fossil Record.


Extinctions On A Large Scale-

Many extinctions continue to occur today and everyday, despite human (H. sapiens) interaction, but the one's that make the headline news are the global "Mass" Extinctions like the ones Humans are causing or are we? (I'll get to that soon enough.) and the infamous K-T Event.

Here are a Few of the Infamous Mass Extinctions, their Time Periods, Evidence and Possible Factors:


  • The K-T Boundary- 65 million Years Ago- a.k.a. the Extinction of the Dinosaurs- This is marked by a higher concentrated layer of Irridium (rare on Earth, but abundant in meteors) at the boundary of the Cretaceous ("K") and Tertiary ("T")  periods. The "K" for Cretaceous is used as a notation to prevent confusion with the Cambrian and Carboniferous periods. Approximately 68% of all life on Earth was wiped out in this event. The Irridium indicates a definite meteor strike, but was that the finger that fired the loaded gun of Evolution? Possibly, but I have another idea. If one were to go into the Badlands of Alberta, Canada, Outside of Drumheller, you would see some of the best evidence of the end of the Cretaceous. As the Fossil Record shows, the Dinosaurian speciation was down to 12 individual speies of each group around the end of the Cretaceous, yet the the fossils seem to end a few feet below the irridium line, indicating that the meteor strike had not done them in, something else. However, that's not to say that it did NOT wipe them out, but rather, as fossils are extremely rare, some may not have fossilized, so there's really NO way to tell. We KNOW it was an environmental change but the exact combination of the factors is nearly impossible to tell.
The Permian-250 million years ago-The LARGEST Extinction of them all yet NOT the most famous, ironically! In this Extinction, 98% of ALL life on Earth was Obliterated and just vanished. The case is the same for the K-T Boundary, as well as ALL the extinctions in Earth's history.

As you all can see, Extinction is a VERY complicated topic and I am already exhausted from typing it honestly. lol! ;P The most important thing to remember is when you hear about Extinction theories and hypotheses, keep in mind that it takes MORE than ONE factor to cause extinctions!!! In fact, ALL extinctions share the same basic trait in common with one another is that they share the same factors for the most part, the ENVIRONMENT, yet the combinations of those factors differ with each one!  I hope you enjoyed and I encourage you to get in touch with experts and ANY of the Open Access Journals, such as PLos One and continue to read up on it if you have ANY further questions! Take Care, Readers! Talk to you Tomorrow!! :)

Fossil Fact #10!!!!!!!

Due to the load of so much on my plate, I'm afraid I'm going to have to speed right through this Fact, if I want to meet my personal deadlines, so let's begin!!!


The Ceratopsians- Horned Champions of the Cretaceous

Possibly the most famous of all the armored herbiverous dinosaurs on Earth, the Ceratopsians were, indeed, some of the most successful and lasting on our childhoods hearts. However, I'm going to cover as best I can and as hastily as I can if I am going to squeeze in two Facts today, with some of the latest research.

What is a Ceratopsian?

As simple as this may sound to most of my "older" readers (by "older," I mean those who have been with me since I started this blog.), there are still a number of folks who may know what they are but, simultaneously not know what they are, if you follow me. Everyone's familiar with them, if they are not familiar with term, like Triceratops, Torosaurus, Styracosaurus, etc. The term "Ceratopsian" is a variation of the scientific family name "Ceratopsida," which means, ironically, "Horned Face." This group has been an obvious success so I doubt I will cover into too much depth into their evolution, as, honestly, I'm completely clear on.

The Ceratopsians were known for their unusually thick and gragantuan "frills" that provided protection for the major arteries in the neck, and held an impressive armory of weapons on the some of the well-known, larger Cretaceous taxa, Triceratops horridus, Torosaurus, and their kin. Though not all had the impressive assortment of weaponry, some had frills whose sheer glance would make any intelligent theropod re-think it's position or just high-tail it out of there!


Ceratopsian Behavior:

Thankfully I need not repeat myself when I discuss behavior from the Fossil Record. This is more of an abstract concept and requires more imagination as, well, people have conflicting views when they literrally look at the same thing. Prior to Paleontologists like Dr. Robert T. Bakker, and Dr. John "Jack" R. Horner, the view of the Dinosauria were big, dumb, lizards. Yet, universally, we see them as living animals with as much an ability to survive as any animal today, if not better. The Ceratopsians were, in my opinion, pretty docile, and would only attack when threatened, as any other animal.  Other than that, very little canbe gained from their remains, no matter how complete, which leads into the next section of this Fact: Anatomy.


A Quick Over-View Of Ceratopsian Anatomy:

Other than being Ornithischians ("bird-hipped," Pronounced, ORN-ITH-SCK-IANS), these herbivores are known for their massive frills. Sadly, new research shows that structurally, these frills' primary function was display, and then defense. I'm not saying that defense wouldn't have been an option, I mean, if display were the primary and ONLY function, then evolution wouldn't have needed a large head crest to show off as other animals do. The ONLY ceratopsian species whose frill is solid bone, was the infamous Triceratops horridus. As stated, if the frills were used for defense only, then evolution would have standardized the design, unless, it was as equipped as necessary to handle the perils and predators of it's particular ecosystem (i.e. The sheep-sized Protoceratops of Cretaceous Mongolia doesn't need to be as well-equipped as the North American Triceratops or Torosaurus.

New research by Dr. Horner of Montana and his colleague, whose name escapes me for the moment, was published in the article in PLos One on the growth of Triceratops horridus and Pachycephalosaurus. According to them, the different taxa for these families were actually growth stages of well-known taxa (i.e. Dracorex hogwartsia, and Stygimoloch were actually growth stages of Pachycephalosaurus, respectively.). As farfetched as this may seem, it seems an even larger changed when it came to the Triceratops. However, no information on the differences in the sexes has been found, even with the detailed studies.


That about wraps up this quick Fact, and I'm sorry if the quality wasn't as expected, but if I wanted to fulfill my ambitions, some sacrifices had to be made. :( Again, sorry, readers.

What does this Weekend Hold for PaleoQuest?

I'm aware of the fact that I personally said that the next post was going to be the tenth Fact, yet I wanted to lay out, more for my benefit, than for yours, how this weekend is going to go for PaleoQuest. First of all, tonight, I will do an unprecedented (well...unprecedented for me, anyway.) two posts sequentially in one day. These two posts are the last two topics on the poll before I delete it. I will still cover the Ceraptopsians and Extinctions, in that exact order, so in a way, it's a paleo bargain. That is this afternoon due to the fact, I want to move on from this little series I'm in for you guys, the readers. Following the tenth and eleventh Facts, I'm going to Live Blog my piece for Art Evolved, which is due November 1st!! Despite the setbacks I have with posting pictures, I will attempt to do my very best with this as this will be my FIRST live-blogging effort ever on this blog. Again, please bear with me. Other than that, there is nothing else beyond that, except for me just posting freely like everyone else on the blogosphere. Anywho, Stay tuned and expect those SOON!!!

Monday, October 19, 2009

Blogging For A Year And Still Going Strong.....

I honestly find it hard to believe that I have been blogging for a year! Today is the 1st Birthday of PaleoQuest and my first anniversary as a blogger on the Paleo Blogosphere! Despite the known setbacks due to school, I realized I wanted to share my passion with the world and teach, and I did so, making some great friends on here along the way. Before I share anything about my past year, I want to sincerely apologize for my absence as of late. School, which has been my excuse before and nussiance, proceeds to do just that. Fortunately, I am away for a good cause, which is to fufill my dream of being a Vertebrate Paleontologist, hence the name of this blog. My success is due to the assistance and support of these particular bloggers as I joined their ranks as a young paleo enthusisast and self-proclaimed Amateur Paleontologist. Here is how I got here:


September 2008: Genesis
I decided to join the blogosphere after stumbling onto Traumador's blog through a random search on Google Images on Tyrannosaur infants, which, in turn led me, even more specifically on Traumador's Excellent Jurassic Park film reviews from 2007. My first brief visit fed my curiousity and decided to explore more of the site. And, lo! It wasn't long before I realized I liked his blog and began communicating with him through his comments page and e-mail. Honestly, this little T. rex has been THE best "virtual friend" on the blogosphere a guy could ask for! I owe him a lot!!

September 2008: PaleoQuest-Version 1.0 (Original)
Shortly afterward, I decided to start PaleoQuest. Only this is the version Traumador SHOULD remember. As a fresh blogger, I was merely experimenting with the features of Blogger with simple posts, gadgets, etc. Sadly, I was "booted" out of my first Google address, from a simple, yet ludicrous reason. Since, I could not log back in to my blog, I decided to move on and create this one. Because I could not log back in with my original account, I could not delete it. So, it must be on the blogosphere still: http://raptor-paleoquest.blogspot.com/. If any of you readers find it or not let me know.

October 2008: PaleoQuest-Version 2.0 (Current):
In October of 2008, I started the one you know today and the one I still use. I have been blogging for approximately ONE year today. I am extremely proud of myself especially considering the fact that school has me on such a short leash. That's basically all there is to this one, except, I met several of my closest "virtual friends" through this version. Here are some of the first ones:

  • Jason "Naveed" Westby-Naveed's Realm- One of my first friends on the blogosphere, Naveed welcomed me onto the blogosphere and began subscribing very early on shortly after Traumador. Shortly after he left a comment on my first Fossil Fact, I clicked his name to learn more about him on his profile. Afterward, I proceeded to his blog and found it pretty cool! His interests are in Cryptozoology, the Paranormal, Science Fiction, and, most importantly Chthulu (spelling?), in addition to Paleontology.
  • Traumador the Tyrannosaur-The Tyrannosaur Chronicles- My first follower and friend on the blogosphere. Like Naveed, he showed me the ropes of Paleontology and blogging. Trust me, he does justice for the Coelurosaurs. He probably doesn't need much introduction, but, still, a little more can't hurt. ;) Affilliated with the Amateur Multimedia Theatre Troupe from Drumheller, Alberta, Canada, Prehistoric Insanity Productions, his blog is a sight and read to behold if one hasn't already.
  • OilIsMastery-Oil Is Mastery- My third friend and follower on the Blogosphere. His blog is more of a multitude of different scientific fields, which the author's main goal is to get his readers to think. Ranging from Physics, to Paleontology, and Geology, even Anthropology, his blog is a good one to visit to get your mind going.
Those are among a few of my influences on the blogosphere, though I can assure you that there are many more as I continued to meet each of them as time went on. Readers, you can look for more of my influences on my blogroll. Anywho, thanks for sticking with me readers and I hope you will continue to stick with me as I strive to reach my goal and complete my PaleoQuest!!

Next: The Horned Champions of the Cretaceous-The Ceratopsians!!

Sunday, September 27, 2009

Fossil Fact #9!!!!!!!!!!!!!!!!!!

Like the previous post, I am short on time for posting, so let's go ahead and get started. This one is a continuation of covering the topics voted on in the poll on the right-hand side of the blog. The Ninth Fact is covering the Tyrannosauridae. This group should need no introduction and this post will be in the same format as the last one and the others for that matter, obviously.  So, let's begin!

The Tyrannosaurs- From Man-sized Jackals to Gargantuan Apex Predators

What makes a theropod a Tyrannosaur:

The Tyrannosaurs are characterized mainly by the shape of their teeth, and the powerful jaws, as well as gracile to heavy stature. The D-shaped teeth are serrated on both sides and usually curve backwards, indicating the ability to rip apart a carcass with ease. This design first started in the earliest known ones like Guanlong wucaii and Dilong paradoxus and then continued in the large, powerful Late Cretaceous members, like T. rex.

Tyrannosaurs, however, are not really known for their gracility (Slenderness) and are more characterized as large, well-muscled, powerful brutes. This heavy stature wasn't evident in the earlier members, but were well defined in the later members like Daspletosaurus, Tyrannosaurus rex, and Tyrannosaurus bataar ( Tarbosaurus). There are a few members that increased in size, yet kept their gacile stature, like Albertosaurus.

What they are known for are their bite force, which is exactly what their jaw is designed for. The majority of the bite force is correlated with the increase in weight and bulk in later Tyrannosaurs.

This group is also known for the small, dual clawed, fore-limbs, whose function is still under controversy. However, the early Tyrannosaurs did not have the dual clawed, small forelimbs, but had the long three-digit, fore claws.


The Early Tyrannosaurs- The Tyrannosaur Dark Ages and "T. rex's Granddaddy"(Jurassic Period-208 million years ago-145 million years ago)

What I mean by "Dark Ages" is that this is the part of their evolution that we are, seriously, in the dark about. It wasn't until Guanlong that we even knew (Or, at least, I knew) the lineage extended that far back  and reclassified T. rex from being a Carnosaur as a Coelurosaur. We really don't know much about this time in their evolution, except a large mass grave found by James C. Clark in China with Xu Xing, containing layer upon layer of doomed theropod dinosaurs. That's our only clear indication of the lineage of the Tyrannosaurs.

Let me tell you a little bit about Guanlong, the "T. rex granddaddy," as it is popularly referred to by the public. Guanlong is most noted for that odd crest on top of it's head, similar to Cassowary of Australia. Unlike later Tyrannosaurus is it's notable gracile stature, lengthened fore limbs, that happen to have three digits like most other theropod groups.

The behavior of this animal has been related to the jackles of the African savannah (however, the jackles are the active predators most of the time and not the lions.) in that they were scavengers. I believe that they were active predators with the possibility of pack hunting or family groups.

Other than this limited information, there is not much to say on this part of their evolution, other than check out Wikipedia.

The Reign of the Tyrannosaurs- The Tyrannosaurs At their Prime (Cretaceous- 144 million years ago-65 million years ago) 

The Cretaceous points out the success of the Tyrannosaurs as we see them diverge through genetic drift and migration filling in almost every predatory niche in the ecosystem and we see a lot of diversity in the other fauna as well.

Despite the gaps in the fossil record of this period on their evolution, we have a much better idea and a much clearer picture of their evolution than we did of the Jurassic period. Some of the Tyrannosaurs grew larger in size and retained their gracile stature, like Albertosaurus sarcophagus and those that have not grown any larger than Dilong paradoxus and have retained that gracile stature like Nanotyrannus lancensis and the newly discovered, Raptorex kreigsteini. These animals filled in the second level predator status of the ecosystem and, some like Raptorex, are on the direct line to Tyrannosaurus rex.

Others sacrificed their gracility for power and a larger head and, a larger, more developed brain, than other theropod groups, (though not as much as the Dromaeosauridae, or the "raptors."), like Daspletosaurus, Tyrannosaurus bataar and Tyrannosaurus rex.

Another notable fact about this family is that every one is rare. VERY few articulate, complete remains have been found and that is why classification and studying their evolution is so frustrating and difficult.


For those of you who did not mind my, indifferent tone, I hope you enjoyed it! And, those who did not, please let me know of how I could have improved it. ;) I also would like some feedback on accuracy and writing ability! Thanks! :D

Anywho, here are a list of sites to visit for more information on this family:

NEXT: The Ceratopsians-Champions of Defense and of the Cretaceous!!

Monday, September 21, 2009

Artwork of the Day #11!!!!!!



Skull of the Cretaceous Predatory fish Xiphactinus audax at the St Louis Science Center.  I took this on one of the trips there, this summer.  (Note: You can find this on my Deviant Art page. ;))

Sunday, September 20, 2009

Fossil Fact #8!!!!!!!!!!!!!!

Now that I actually have the time to post, it's time to finally cover the topics that you, readers, voted on in the poll, in a series of Fossil Facts. Considering the amount of time that has past since the last Fact, I felt this was overdue and I did promise these lessons when I had the chance. Interestingly enough, it was the idea and support from my "friends" over at Dinosaur Home, to, not only do a special Fact over on their blog, but make this Fact  a reality. And, even more exciting, is the updated Post edit/Creation page, as I like to call it.

Anywho, as I don't have much time for this one, I should tell you this one is a brief overview of the Evolution of Theropods according to the Fossil Record. So, Lets get started!!

What is a Theropod?

Because of the possibility that there are new readers, and those who are not familiar with the technical vocabulary, allow me to explain what "Theropod" means, simply. Simply, and briefly, the term "theropod," literally "beast-feet" is the term referencing to the dinosaurian bi-pedal carnivores that, literally dominated the landscape of the Mesozoic. Theropods, as will be covered shortly, according to the Fossi Record (despite the obvious gaps) branched off into a number of different groups based on certain aspects of their skeletal anatomy.

Theropods Emerge- Late Triassic (~208 million years ago):

Despite the evidence of carniverous dinosaurs somewhat earlier, (i.e. Eoraptor, and Herrarasaurus), "true" theropods, like Coelophysis bauri, didn't evolve until later. Coelophysis is considered the earliest known theropod, because of some pretty crucial reasons, namely his body plan. If one were to actually examine a C. bauri skeleton, then one would think he/she was, perhaps, looking at a bird, which, because of it's hollow bones, is it's namesake. This animal had a long flexible vertebrae in the S-shaped neck and tail. The joints of the limbs to the torso allow for fluid movement, and, though, primitive, Coelophysis forelimbs were essential for the manipulation of prey. Though, not heavy and powerful as some of it's predecessors or the reptiles of the time, C. bauri is built for speed and his upright posture gave him the advantage over it's archosaurian neighbors.

Syntarsus, and Dilophosaurus to Ceratosaurus and Allosaurus- Theropods Diverge (Jurassic period, 208 million years ago-145 million years ago):

The Jurassic was not only the reign of the Theropods, but other groups as well. Of course, this post is covering the Theropods. At the beginning of the Jurassic, change was in the air as the Dinosaurs have control of the land. Although, one may not realize it, but many groups that appeared in the Triassic were beginning to branch away from each other, as animals began to migrate and the continents shifted during this period. Pangaea was now breaking up, though the modern continents still haven't arrived.

During the start, we have little predators similar in size and design as Coelophysis, Syntarsus. These animals still have the build: not for power, but for speed. Syntarsus, despite being the same build and no longer has to compete with the primitive archosaurs of the Triassic, is not the terror on the block. Even at the beginning major animal groups were branching off, with some becoming larger, and heavier, while others are remaining gracile. One of the stars of the book and film Jurassic Park, is around, without the frill and the poison glands, and about 2-3 times larger, yet still slender and gracile, Dilophosaurus. Still primitive, because of the five fingered fore-claws, indicating that he just became a biped from a quadroped. He looked like he just started walking upright. Also, his build is like the smaller Syntarsus and the Triassic Coelophysis. His most unusual feature are the two, thin, blood-vessel, filled crests at the top of it's head, possibly for display, hence the name. This theropods jaws were very unusual, as they're pretty slender and the teeth are long and blade like. (The bone crushing teeth of the Tyrannosaurs, do appear during this period, though they won't appear until the mid to late Jurassic.) This jaw design suggests to me that Dilophosaurus wasn't built for hunting the large prosauropods like Anchisaurus. Since behavior doesn't fossilize, I can only go on what I have read, heard and seen in the documentaries and books on the subject (For example, most of this information, is based off of the Discovery Channel documentary When Dinosaurs Roamed America, which covers MOST of the Mesozoic and goes into it more deeply than Walking with Dinosaurs and shows us the fossil evidence of each scene of the show.). So, readers, bare with me, I haven't been around enough specimens to really get my own opinion, thanks to KY.

Anywho, as the animals continue to branch off, we have the carniverous Ceratosaurus of North America, and the tyrannosaurid Guanlong wucaii, of Asia.  In the Late Jurassic, we have large, more robust animals like Allosaurus and the Torvosaurus. In the mid to late Jurassic, we see the transitional form of Archaeopteryx. The Jurassic founds an evolutionary boom, similar in size to the Cambrian, only this boom continues into the Cretaceous.

Tyrannosaurs, Birds, Mammals, Raptors, and Flowers- The Peak of their Reign and, Sadly, their Tragic End (Cretaceous period, 145 million years ago to 65 million years ago):

The Cretaceous is one of the most famous periods of the Mesozoic and Prehistory with the public, yet the most commonly misunderstood, as it is second only to the Jurassic period, in terms of popularity. This is where the world starts to look more modern and less alien.

Here is a quick overview of the Cretacous Predators:

Tyrannosauridae- This family emerged in the Jurassic period as medium sized, gracile, feathered animals. One of the most unique feature of this family are the design of their teeth. The D-shaped, serrated, banana-sized teeth bagan in Guanlong and Dilong, and taken into extremes in Tyranosaurus rex. This family belongs to the same group as the "Raptors" (The Dromaeosauridae and the Troodontidae), the Coelurosauria (the most bird-like group of theropods.)  As such, they are some of, if not, the most advanced animals of the time.
(i.e. Guanlong wucaii, Dilong paradoxus, Raptorex kreigsteini, Daspletosaurus torosus, Albertosaurus sarcophagus, Gorgosaurus libratus, Nanotyrannus lancensis, Tyrannosaurus bataar (Tarbosaurus) and, of course, Tyrannosaurus rex.)

 The "Raptors"- Called such because of Michael Crichton's Jurassic Park, this group includes more than just the Dromaeosaurs. These also include the Troodonts. These families share a similar body plan, such as the retractable "Killing claw" and large complez brains and bird like features. Some even have feathers. (Fauna include: Velociraptor mongoliensis, Deinonychus anhtirropus, Utahraptor, Troodon, Jinfengopteryx, Microraptor gui, Dromaeosaurus, among others.)

The Spinosauridae- The odd crocidilian-snouted theropods. Not much to say other than this group is poorly understood, as there is not much fossil evidence for these guys.  (Fauna: Spinosaurus aegyptiacus, Suchomimus tenerensis, Baryonyx walkeri, and the others, who are still controversial, that I won't mention to have this post be as accurate as it can be.)

The Allosauroids and the Carcharodontisaurs- There is a long standing debate about how the Carcharodontisaurs emerged. Some say they emerged from the Allosaurids of the Jurassic period. Others say they have a separate lineage. Other than that, I can't say much about them other than they include the largest carnivores that have ever walked the Earth!

Birds-This is obviously, still controversial, but I'll stil mention them anyway.

Those are some of the major groups that inhabitated and terrorized the Cretaceous landscape. Hope you enjoyed and learned something today. ;)

NEXT: THE FAMILY TREE OF "SUE" AND TRAUMADOR!!!!! STAY TUNED!!!!

Monday, September 14, 2009

Some Thoughts About The Blog

As the title says, this post is just some self-evaluation about this blog. For those who have been here since I started back in October of '08, you all know about the quality, you all know the changes that have happened on this blog within ONE year of it's genesis. Those who have JUST came across this blog, I say "Welcome!" My point? There's none, really, other than just reflection as this blog is approaching it's First Birthday! I find it hard to believe I have been on the Paleo Blogosphere for nearly a year, and, already, I have managed to obtain 11 followers, a feat which takes some bloggers some time to get started. Now, I am not trying to gloat, but I am impressed with myself. Aside from that, the people I've "met" and the things I've learned, are nothing short of spectacular. This has been a fantastic opportunity, and one not easy to do. I feel fortunate to have such fantastic guidance on this site, despite my shortcomings (Those who know me, know what I'm referring to all too well, lol.).


Next, I want to talk about the main curiousity of you readers, the Future. So, I answer "What's next?" for the blog. Well, I'm not sure. I find it difficult to be making commitments and then School snatching me from the web. I know I said I'll be covering the topics, you all voted on in the Poll, and I will. I also wanted to tell you of a commitment I told Dr. Andrew Farke, the Open Source Paleontologist. He had the idea of a collaborative effort to write a paper on the Evolution of Ornithischian posture....or something to that extent. :P Those who participate in the research will be listed as the authors of this paper going up for Plos One. It's excellent, though I am still vague as to how I will participate. (Hopefully, I will cover it in the next post. Sorry. :P) I know it has something to do with posting some research here. Hmm....Sorry readers, I'll be sure and ask him, and then I'll let you know, next post.


Other than that, that's what will happen in the next few posts. Although, if you follow me on Twitter, then you'll know I will be still announcing when posts are up and the subject of the next one, but not the date, so I don't break any promises. In fact, just like tomorrow, it's up in the air. So, until next time, take care and see you Next Post!!

Sunday, September 13, 2009

Artwork of the Day #10!!!!!!!


The classic Charles R. Knight painting of the Tyrannosaurid, Dryptosaurus (a.k.a. Laelaps, as this taxa was known by at the time of this painting.) Thanks, Brian Switek, of the Science Blog, "Laelaps," for having the original site for "Laelaps," still on the blogosphere (In truth, I stumbled upon this, thanks to Google Images.)