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Long Postings

December 26, 2013, 5:39 pm
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Want a long post, you have to wait a little longer in your day; that and I honestly did not realize what time it was because I have been out and when in avoiding my computer because I am having trouble focusing on writing. On with the show!
My toy Dilophosaurus never had the ability to spit 20 feet as the ones in the Jurassic Park game are noted to achieve but it did, and still does (yes I have Jurassic Park Dilophosaurus and Velociraptor Series 1 figures from 1993; and I may still have Alan Grant too, but he is not as cool), manage a few feet when it is given a good hearty squeeze; Velociraptor bites when you squeeze the hindlimbs medially for those out of the know. That Dilophosaurus does not have a frill and, honestly, I am a bit sad that it does not have the associated frill given that that would be very accurate for the story and far more entertaining to play with. Dilophosaurus has far more popular culture credit than Jurassic Park, though.

One of the more popular areas that Dilophosaurus has marched into is the video game world. Rather than only making a mark in Jurassic Park games Dilophosaurus makes appearances in games like Primal Carnage. It has also been modded into other games like Zoo Tycoon, but I think Primal Carnage may be the non-Jurassic Park height of dinosaur video games; where else can you hunt dinosaurs with and against other people, or hunt people as dinosaurs, online after all? Dilophosaurus has also been modded into a lot of Minecraft and Spore videos.

"Analog" versions of Dilophosaurus in popular culture include many different skeletal reconstructions and displays, some of which we have seen during this week. The variation in these representations of Dilophosaurus are fantastic and actually fun to compare to one another. The Museum of Paleontology at Berkley has gone far enough to put together an audio guided tour of their analog/digital combined Dilophosaurus exhibit that is a lot of fun to listen to (Sam Welles made a few good points about the frill and skeletal anatomy that would have supported the frill). Despite stepping on some feet with the present known facts, there are a lot of supporting characters that back up a lot of the reconstructions out there; some sculptors and paleontologists putting them together highlight specifics more than other characters obviously. There are reasons for that, but we cannot, and do not have the time, to delve into every reconstruction and determine why certain characteristics were highlighted over others.
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Too Long To Hold My Tail Up

December 27, 2013, 8:07 am
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©Charles Knight
The old view of sauropods, due to their girth and sheer size, was that of a swamp and marsh dwelling creature supporting its weight through buoyancy in the waters. Dragging its tail and sometimes snorkeling in the deep Jurassic waters, Apatosaurus was thought to be a slowly moving gentle giant capable only of outlasting predators by hiding in the murky depths. Charles Knight, and others, captured this wonderfully in their illustrations of sauropods like this Apatosaurus printed under the name of Brontosaurus. Three species of Apatosaurus are presently recognized as valid (Apatosaurus excelsus Marsh, 1879;Apatosaurus louisae Holland, 1915; andApatosaurus parvus Peterson and Gilmore, 1902). The average size of these monstrously large animals was around 75ft (23m) and estimates range between 16 and 35 tonnes in mass, making the original hypotheses of buoyancy for weight support much more logical; though obviously we know more now about the anatomical engineering marvel of sauropod vertebral columns and limbs.
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Spanning A Chasm

December 28, 2013, 1:37 pm
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O.C. Marsh
The 1896 diagram of Apatosaurus excelsus drawn out by Othniel Marsh depicts an animal with a very smooth body curvature from the head to the tail. The skeleton, according to Marsh, was not very rigid, making the tail and neck droop and leading to the assumption that the neck and tail were not heavily muscled; meaning that they were lacking the proper amount of muscle to hold them parallel to the ground. The neck, though parallel in this image, was assumed to possess an ability to snorkel, being held at a nearly perpendicular angle to the ground. Since that description of the neck was published it has been discovered that the bones of the neck, in order to sit at the perpendicular angle, were positioned incorrectly or broken. The much more parallel orientation is much closer to an actual articulation and "comfortable" posture for these dinosaurs. Additionally, the tail has been changed in posture as well, but that cannot be seen in this image.

©Scott Hartman
The tail, as stated before, has been changed and here captured by Scott Hartman exactly as described. This specimen of Apatosaurus ajax has an upward kink at the base of the tail. The tail then extends horizontally posterior rather than deflecting downward until it drags on the ground. The tail musculature, and rigidity through tendons and ligaments, allowed for the tail to be used as a counterbalance to the neck and also as a weapon system in a pinch. The kink at the base creates a more stabilized area for muscle attachment above the pelvic girdle without fusion of vertebral neural spines in this area; this is not expressly noted in any paper I have read, but the arrangement suggests a non-fused but larger attachment surface when looking at it in profile.
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Loving Brontosaurus

December 29, 2013, 1:31 pm
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Apatosaurus, once our loving friend Brontosaurus as well, is now and has always been a favorite of children everywhere. This is born out in the sheer number of children's books devoted to one or the other as well as the number of sites online that post child friendly reading levels of facts. We have our main fact pages like the New Zealand based science encyclopedia Science Kids, Kids Dig Dinos, and even KidsDinos. There is also a really weird song from 1978 that should entertain people if nothing else. More relevant, only because it is a lot more recently done, is the I'm A Dinosaur video for Apatosaurus. The dinosaur is a lot less factual and just kind of weird compared to past episodes though.



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Gertie, and Other Appearances

December 30, 2013, 6:01 pm
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Apatosaurus first showed up on film, as Brontosaurus, as Gertie, the lovable cartoon dinosaur of the silent film era.

Winsor McCray's 1914 cartoon was not to be the only popular appearance of either Brontosaurus or Apatosaurus. Slightly updated versions of the long-necked cartoon made their way into The Land Before Time decades later; though the argument for another sauropod "fathering" this reconstruction can certainly be made. Between those two cartoons there was Disney's Fantasia as well.

This version was an in-between reconstruction with the swamp dwelling behemoths still living in the water. There was not as much emphasis on Brontosaurus/Apatosaurus as there was in Gertie or The Land Before Time. Regardless, The Rite of Spring classes up that dinosaur duel tremendously. Modern interpretations of Apatosaurus are most accurately portrayed in When Dinosaurs Roamed America




and Walking with Dinosaurs in tandem; however, in the latter, it is only shown in two scenes during the Ballad of Big Al special episode.
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Histology and History

December 31, 2013, 9:46 am
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Apatosaurus and Brontosaurus alike have long histories in the literature. The most modern scientific inquiries into Apatosaurus have looked at ontogeny through histology, amongst other avenues of research including CT scanning. Specimens of Apatosaurus are, thankfully, continually discovered throughout the Morrison Formations faces in the American Southwest and allow for these sorts of opportunities as well as the description of these new specimens. Sometimes the descriptions of specimens is limited to specific portions of Apatosaurus, which makes sense given that it is such a large animal and that the remains are sometimes fragmentary; as is the case with any fossil remains as we all know. One fragment, just for an example, that has been described independently is a portion of lower jaw and the palate of a Diplodocus and a comparison of this to the skull of Apatosaurus; the paper is older, but it is a quality description and comparison of sauropod skulls. If we want to go back to the first description, though, and we do because we enjoy reading historical accounts, we have to go back to Marsh's 1877 publication in the American Journal of Science that first mentioned Apatosaurus and subsequent descriptions of Apatosaurus like that found in 1879's Principal characters of American Jurassic dinosaurs. Part II (Brontosaurus is also mentioned in the 1879 publications).
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Apatosaurus Growth

January 1, 2014, 4:36 pm
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Wednesday's I sometimes have a lot of information to wed through and present. Apatosaurus is one of those dinosaurs that has been studied enough and is well enough known that we could easily fill a book with the information that is known about it. Specifically, for today, however, the point that we are addressing is the growth of Apatosaurus as has been evidenced in the fossil record. The paper on histology from yesterday addressed that issue quite well actually. The study, and other research has approximated adult age to have been reached in Apatosaurus at around 10 years of age; considering the layering of bone during growth it has been stated that this growth was rather quick. Sexual maturity has been approximated to be achieved around the 19th to 21st year of life and lifespans have been determined to top out between 28 and 31 years of age. These approximations were determined by a recent study of two individual specimens. Tomorrow, if there is time, I will contemplate tackling breathing in addition to the popular appeal of Apatosaurus.
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Apatosaur Breathing

January 2, 2014, 11:36 am
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©Dmitry Bogdanov
Apatosaurus has been one of those dinosaurs that every post has included some sort of popular culture reference. Brontosaurus and Apatosaurus were both popular dinosaurs on their own but the synonymization of Brontosaurus with Apatosaurus actually had very little effect on the popularity of either name. Stephen Jay Gould and the United States Post Office defended using the name Brontosaurus in favor of Apatosaurus due to the popularity of Brontosaurus. The one highly noticed venue of popular culture that has seemingly escaped Apatosaurus is Jurassic Park, but anyone that has read the book should remember that there were 17 Apatosaurs roaming Jurassic Park along with all of those Brachiosaurs that "moved in herds". They do appear in modifications and base models of games like Zoo Tycoon and Spore.

There was also the question of breathing that needed to be settled; a neck that long produces some rather difficult engineering problems. The trachea of an Apatosaurus is a long anatomical structure. The pressure in the lungs and that outside of the body needs to be great enough that the volume of oxygen required for breathing can be taken into the lungs and carbon dioxide expelled or the animal, our Apatosaurus, will effectively suffocate. How does a 20 to 22 ton animal create the pressure required for breathing? How much pressure might that be exactly? Studies have shown that an estimated 30 ton Apatosaurus may have had up to 184 liters of dead-space volume in the thoracic cavity. Dead-space volume is air between breaths in oral cavity, trachea, and lungs. The assumption is that Apatosaurus possessed a crocodilian like breathing apparatus that lacks a diaphragm. Some estimates of the ability to replace this air have been done comparing Apatosaurus and ideal conditions of taxa specific respiratory systems. Reptilian systems are vastly inadequate to replace this volume and would have suffocated Apatosaurus; mammalian and avian systems are better equipped to replace the volumes of air proposed in Apatosaurus systems. Mammalian systems are adequate, but under powered as well, meaning that avian systems remain as the best equipped systems for allowing Apatosaurus to breathe efficiently; another possibility put forth is an unknown and undescribed system that has been lost in the modern world.

It is assumed that a four chambered 500 liter heart and 900 liter lungs filled a 1700 liter thoracic cavity (300 liters of tissue) in Apatosaurus. These assumptions in conjunction with reptilian resting metabolic rates and avian respiration, it has been hypothesized that an Apatosaurus required 69 gallons of water a day to live in addition to massive amounts of vegetation that it must have consumed.
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Hollow in Form, But Not Substance

January 3, 2014, 2:10 pm
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©Jeff Martz via National Park Service
Just to note, before we really begin, how interesting the name is, Coelophysis refers to the bones of the animal while the specific epithet (bauri) honors an anatomist who was at the time working with Marsh; this is interesting because the animal was named by Cope (Ceolophysis in 1889 from the original Coelurus Cope 1887) who described Baur as "the distinguished comparative anatomist of New Haven" while stating that he could not agree with Marsh on the genus being placed in any known order. Backhanded dismissals of other scientists aside, Coelophysis bauri has proven to be a difficult animal to pin down. As an early dinosaur of the Triassic, Coelophysis has many primitive characters as well as some traits that are early building blocks of all theropod dinosaurs. These include, in part, bone composition as well as primitive traits in the forelimbs and hindlimbs, and a long narrow head filled with serrated teeth. Primitively, the mouth is filled slightly more than halfway with teeth; the number of teeth and extension of their length along the jaw would be reduced as theropods evolved further. The lacrimal was devoid of ornamentation as well but some was discovered on the nasal; a primitive trait in comparison to more derived theropods. Coelophysis was also relatively small for a dinosaur as it was the size of a large dog at approximately 9.8 feet (3 meters) and around 3 feet (1 meter) tall at the shoulder. Peculiarly, Coelophysis is known to have fused clavicles, or a furcula, a trait usually seen in birds and bird-like dinosaurs. The inclusion of the furcula this early in dinosaur history is quite interesting and important in the development of theropods and birds.
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Just a Typical Dinosaur

January 4, 2014, 3:59 pm
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©Nobu Tamura
Triassic dinosaurs like Coelophysis sometimes seem to be very stereotypically illustrated. The reason for that, of course, is because a lot of the generic traits of dinosaurs have their origin in the earliest Triassic dinosaurs like Coelophysis. That said, they are fascinating little creatures, Coelophysis, because they are the basic model for so many more derived theropod dinosaurs that evolved later in the history of dinosaurs. The elongate skull of Coelophysis and the overall gracile form are distinctive traits of Coelophysis that we can easily see in most illustrations of the animal. In some illustrations, in fact, Coelophysis appears very snake-like. Thankfully, we also have other illustrations like this one that are more robust in form.

©John Conway
Not too long ago, within the past decade  or so, dinosaur feathering has become much more universal than it once was. There is not necessarily a problem with this trend, but like all trends in art, they come and go and, with scientific illustration, are usually based on the majority consensus. That consensus right now has a lot more feathering visible on most known dinosaur genera. Illustrations like this one, lacking the feathering on the majority of the head, with some quill-like structures on the neck, are quickly becoming less and less normal and are even becoming unfavorable in many circles. The gaunt appearance of the head of this Coelophysis, however, follows the skull closely and accentuates the bumps and ridges of the bones exceptionally well. Despite this style of interpretation losing some favor in the scientific community it is still a valid interpretation and takes into account the anatomy of the skull particularly well.
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Gracefully Entering the Room

January 5, 2014, 2:31 pm
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Kids love a slinking low profile dinosaur as much as they do a giant bone crusher. The slinking ones are sometimes not as scary, but they are good for darting in and making quick strikes at prey; kids love dinosaurs attacking their prey and everyone likes fast action. Regardless, there are a few good fact pages for this fast little dinosaur to dart in from and steal the show. There is KidsDinos and KidsDigDinos. The higher level readers can turn to Animal Planet and get more in depth information that challenges their reading level a bit more. The BBC has put together a page that has a little bit of written information in addition to a few featured clips from Walking With Dinosaurs, to give those avid little readers a bit of a break. The final relaxing point of today for our little scientist buddies is the ample number of coloring pages available. This is one of my favorites:

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Coelophysis the Model

January 6, 2014, 1:25 pm
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The models used for Walking with Dinosaurs with the Coelophysis segments were a bit older, given that Walking with Dinosaurs was produced prior to the rest of the "Walking with" series and were far more puppet-like than many dinosaur documentary models. Many of the dinosaur models in those sorts of documentaries are wireframe models done on computers. The Coelophysis compilation of models, both computer and puppet, still turn out quite well together over time. There should not be much surprise in how well it turns out, but if you have not seen it you really should check it out here. Coelophysis was built for speed, as is attested to by this clip from Discovery.

Coelophysis was built for running and jumping, clearly, and the skeleton is the key to those clues that lead to the knowledge of the manner of life that Coelophysis lead. Thanks to those computer models we can see Coelophysis come to life from those bones. Hurray for modern technology!

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Ghost Ranch Writers

January 7, 2014, 1:13 pm
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Many people have discussed, researched, and written about Coelophysis. Sometimes those writings appear in books, like this chapter on variation within Coelophysis bauri by Edwin Colbert that can be found in 1990's Dinosaur Systematics edited by Carpenter and Currie. That variation and the study of it leads to comparisons between taxa ultimately. The very similar Syntarsus rhodesiensis, recently renamed Megapnosaurus rhodesiensis due to a conflict of the name with a beetle, is a genus of coelophysid dinosaur recovered from North America and Africa that is extremely similar to Coelophysis morphologically. Because of the variation of Coelophysis, an in depth comparison of the two genera is necessary to point out the traits that separate them. Less direct comparisons have also been undertaken that look at the cranial mechanics of Coelophysis and later theropods that highlight the traits that began in Coelophysis and evolved over time in the derived specimens that were compared. Last but not least, it is important, in understanding the specimens that have been researched since the first Coelophysis skeletons were described, understanding the location and preservation of the largest deposits of skeletons. Ghost Ranch has been studied and the remains of many Coelophysis and other animals have been documented and researched within the area. Though from 1994, Schwartz and Gillette, discuss the geology and the taphonomy of Ghost Ranch, which provides important contextual information to Coelophysis since so many of the described specimens have originated at Ghost Ranch.
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Sex in the Coelophysis

January 8, 2014, 1:36 pm
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Just so everyone knows, thinking up fun titles is half the enjoyment I get out of writing these everyday; the other half is knowing that someone somewhere is learning or at least questioning what they know and critically thinking thanks to things I publish. Regardless, today I really wanted to mention that Coelophysis remains have exhibited evidence that suggests that these animals were sexually dimorphic. Discovering evidence of sexually dimorphic characters in fossil animals is always an intriguing and important part of being able to interpret potential interactions within populations. Certain sexually dimorphic characters can even lend themselves to interpretations of mating rituals; these are typically based on modern examples of similar characters in extant taxa. The difference in Coelophysis is not based on any interesting crests or additions to the skeletal frame. Instead, the dimorphism is suggested by differences in overall size of specimens; the forms are noted as being "gracile" and "robust". The two specimens initially used to describe these conditions are housed at the American Museum of Natural History and are AMNH 7223 (gracile) and AMNH 7224 (robust). As with many other sexually dimorphic species, the gracile form is thought to be female while the robust form is thought to represent male specimens. These forms are present in all ages of Coelophysis, meaning that the size difference is not only attributable to a difference in species and that sexually dimorphic characters begin to appear early in the life cycle. Gracile forms had longer skulls and necks, short forelimbs, and fused sacral vertebrae whereas robust forms had opposite characters in these areas. Some parental care has been noted in these animals and they have been considered gregarious due to the mass death assemblages at Ghost Ranch in New Mexico; though these may represent coincidental incidents in which food or water was limited and drew in large numbers of animals. Regardless, the sharing of food between adult and juvenile depicted in this image, is very neat and, though it does not show sexual dimorphism explicitly, we can assume that this is the female form with a baby and that they are gregarious animals here at least.
Denver Museum of Nature and Science

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Coelophysis Everywhere

January 9, 2014, 2:38 pm
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Spore is always a good outlet for dinosaur lovers to create models of their favorite dinosaurs. There are a handful of versions out there; this one is much more flamboyant and crazy than many other models. I like how out there the feathering portrayed on this model of Coelophysis is. The imagination and creativity of video game modelers is always pretty interesting and exciting to witness the first time you get to see it. Popularly, in other areas, Coelophysis has appeared in many places. It is featured in many different ways in the state of New Mexico including stamps, coins, and other aspects of being named the State Fossil.  Coelophysis has shown up as toys thanks to Jurassic Park, in part, and was a small enough model that the package actually contained two toys. There are a lot of books around as well including a few dedicated specifically to Coelophysis such as Dinosaur Ghosts: The Mystery of Coelophysis.
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Armor and Spikes

January 10, 2014, 11:52 am
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The Thyreophorans, Stegosaurs and Ankylosaurs, are noted to be heavily armored dinosaurs built equally for defensive and offensive capabilities with some specializing in one or the other end of that spectrum of abilities. One of those beautiful animals that has offensive and defensive capabilities and is alarmingly awe inspiring to look at is Sauropelta edwardsorum Ostrom 1970. Sauropelta was a fantastically imaginary dinosaur backed up by the fact of fossils. I say that only because its anatomical morphology almost makes Sauropelta appear to be an imaginary beast thought up by someone with a great imagination. The tail of this nodosaur was equal to approximately half the body length; a tail not used to counterbalance a long neck has other anatomical implications of course such as use as a weapon. The tail, being that of a nodosaur, was not particularly weaponized though. It, and the rest of the body, was covered in dermal scutes that are individual bony skin plates that have been recovered from a number of specimens. I mentioned that Sauropelta was not only defensively built and the shoulder and neck attest to this by possessing rather enormous (depending on the illustration/interpretation of fossils) shoulder and pro-pectoral spikes along the neck. There will be more discussion about these interpretations over the next week of course.
©John Conway

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Sprawl and Spike

January 11, 2014, 7:15 pm
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Sprawling dinosaurs have widely gone out of fashion, so why does it appear that this dinosaurs is sprawled out? Honestly, we can blame it on the angle and the position of the dinosaur. Sauropelta, as a nodosaur, lacked many of he offensive capabilities of other Thyreophorans such as Stegosaurus and Ankylosaurus. The lack of a tail armament would leave two options for a dinosaur like this; use your shoulder spikes or squat down and use your armor; tail scutes have been argued to have been used as scissors as well (see this coming Monday). In this image we have a top down view of a Sauropelta positioning its spikes and balancing its forelimbs in an awkward manner. This could be either to use those spikes as defense or to use them in the only offensive way something like this could be used; in other words this dinosaur is preparing to check an opponent like a hockey player. Which is correct is up for interpretation.

The second option, checking an opponent, would paint a much livelier image of Sauropelta. We would see a more agile dinosaur than we expect for larger armored animals because it would need some agility to be able to lunge at its attackers with anything resembling accuracy. To portray such litheness in a quadrupedal dinosaur requires a little thought on how "bouncy", for lack of a better word, the dinosaur should look. This lean but powerful fore-body portrayed here can help us to look at Sauropelta as a dinosaur ready for action on the front end in a similar manner to how Stegosaurus' pelvic region and tail is all business and looks as though it can pivot and swing with power. This is not a typical thought concerning nodosaurs and their bigger brethren.
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Minimal Child Influence

January 12, 2014, 11:39 am
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Sauropelta is not a huge mainstream dinosaur and therefore does not impact the world of children's facts anywhere near as much as some dinosaurs have been known to do. It has managed to make it into a few child-friendly and lower level reading friendly webpages however. The easiest among these remains KidsDinos but London's NHM is always a reliable source of easy reading for dinosaurs as well. Pages about Sauropelta do also cater to higher reading abilities as well without too much information or technical jargon, which is always good as well. Pages that manage this the best are, typically, Enchanted Learning (which is a little closer to lower level reading this week) and the compiled data found on About. Videos and coloring pages dedicated to Sauropelta are lacking a bit this week, but that happens and we can be okay with that.
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Scissors of Doom

January 13, 2014, 6:06 am
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Granted the clip I promised on Saturday has nothing to do with Sauropelta itself as a dinosaur, it does exhibit that potential scissor action of the dermal spikes of the tail. The action of the tail may be a little more derived than Sauropelta may have been capable of; however, it is hypothesis that may have some anatomical and physiological support behind it. To see the exact action in play fast forward that clip to 2:20, but remember, the dinosaur depicted had larger scutes and spikes on the tail, so Sauropelta would not have had as much leverage or reach with the scissor action. Sauropelta itself has not been tackled in any major documentaries that have been released or are available online. That, as always, is unfortunate. Early nodosaurs do not garner as much attention as their larger descendants and cousins, and are often left out of documentaries as a result. If anyone knows of a good clip that I did not know of and share, please share it with us!
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Back to the Right Dinosaur

January 14, 2014, 1:46 pm
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Sauropelta shows up in a few bits of literature that are available online; that is always very nice. One of these is dependent on one's ability to get Canadian Journal of Earth Science articles. However, if one does, it explains a nice skeletal and life reconstruction of Sauropelta that are both pretty well done and interesting. Additionally, there is another article that proves useful in reconstructing the world of Ankylosaurs in Utah. Three species are discussed in this review of the Cedar Mountain Formation. While an image of Sauropelta does not appear in this article, its description here puts to rest some of those more fantastical appearances we have seen (but I will leave it to the readers to discover this for themselves).
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