Histology and History

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).

Gertie, and Other Appearances

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.

Loving Brontosaurus

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.

Spanning A Chasm

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.

Too Long To Hold My Tail Up

©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; and Apatosaurus 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.

Long Postings

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.

Merry Christmas Post

My intentions for today were to write a very short post with my old Dilophosaurus drawing in a bit of a festive getup, but I still cannot find that drawing. For those not celebrating Christmas, today is a normal day and we respect that here. Since it is a fairly major holiday for a wide bit of the audience, I will still keep it short. I want everyone to know there is still a rather festive Dilophosaurus available on the internet from illustrator Frank-Joseph Frelier. Instead, have a basal Christmas Ornithopod! We will have a nice long post tomorrow to make up for today.

Chinese Dilophosaurus?

There are papers about Dilophosaurus that are of interest today; providing you do not have family events for Christmas Eve planned. There are some great papers on a supposed Chinese Dilophosaurus, Dilophosaurus sinensis, that describe the species and the discovery of the remains. There are two different papers from 1993 describing these remains. As of this writing, however, only Dilophosaurus wetherilli is recognized as a valid species. Robert Gay, last noted to be teaching in a public school in Arizona, has written two interesting papers that he hosts on his own web page related to Dilophosaurus; one is on sexual dimorphism in Dilophosaurus (abstract available in two places) and the other on a new specimen from the Kayenta Formation. There are, of course, also book excerpts that mention the world renown Dilophosaurus like Kenneth Carpenter's The Carnivorous Dinosaurs. I think one of my favorite short papers for the day, however, is from Andrew Milner and James Kirkland and explores the possibility that many dinosaurs, including Dilophosaurus, from St. George Discovery Site at Johnson Farm (a site in Utah) might be fish eating in part at least. Dilophosaurus jaws do, recall, slightly foreshadow the piscivorous Spinosaurid jaw morphology; and may have had a diet that integrated fish in addition to terrestrial prey.

Jurassic Dilophosaurus

Jurassic Park, home to many dinosaurs of the Cretaceous, was also home to Dilophosaurus. Remember the parts of this wonderful scene that were added by Crichton, retained by Spielberg, and have no known basis from the fossil record and enjoy the scene regardless. Probably my favorite of all the Jurassic Park scenes floating around the internet (also, listen closely near the beginning for the funny and overused slide whistle):

Now, for comparison, view these much more fossil based reconstructions of Dilophosaurus from When Dinosaurs Roamed America and note the differences between the two clips (there will be a Christmas Eve test):

He Means His Jurassic

A good day for letting your children read or watch a video. There are not any dedicated books that are singularly exceptional about Dilophosaurus, in fact, the majority that are about this dinosaur alone are from the 1980's or 1990's and their covers appear extremely out of date. There are some fairly good online fact pages like KidsDigDinos and Enchanted Learning; though these are not usually our favored pages. Enchanted Learning has a somewhat acceptable coloring page, but the one below is quite a bit better; it is quite cartoony however. I had drawn one at some point that I think would be good for coloring, but every time I find it I am happy I found it then I promptly forget to scan it and forget where it is.

Feathers or No Feathers

Geological Museum of the Polish Geological Institute in Warsaw

As has been mentioned in the not so distant past, the origin of feathering has not yet been pinpointed. Assuming that the feather origin occurred very early in the history of the Dinosauria we can begin to see models, and illustrations, of even the earliest theropods with feathering. A feathered Dilophosaurus is actually quite appealing, to toss out an opinion. As opposed to some newer models and illustrations of feathered dinosaurs (opinions coming here) this Dilophosaurus reconstruction looks very appropriate as a feathered dinosaur. The feathers of this model, thankfully, are not ostentatious; their "drab" nature and subdued coloration in this reconstruction are quite fitting for a theropod that would want to blend in with its surroundings while hunting.

Pink Palace Museum, Memphis, TN.

The non-feathered version of Dilophosaurus that is still somewhat popular is usually a drab color as well. The tiger striping of black and brown is a common color scheme for theropods of the past and the present though. Ignoring that, there are a few other issues with this particular model that can be found in other tight skinned and non-feathered theropods. The most characteristic mark in the reconstructions with tightly pulled reptilian skins on the skull is the formation of the notched junction of the premaxilla-maxilla. In comparison with the other reconstruction, the eye is portrayed as much smaller as well. Additionally, the crests of this reconstruction are larger and more brightly colored. The crest is also divided by ridges and depressions not apparent in the previous reconstruction. The taut skin of the more reptilian reconstruction is a bit of a call back to an older age; it is a bit of a vintage reconstruction to say the least.

Double the Crests

©Heather Kyoht Luterman

Meaning "Two Crested Lizard" Dilophosaurus was discovered in 1954 in Arizona's Kayenta Formation. One species is recognized, Dilophosaurus wetherilli, and it is a highly recognizable species. The most characteristic identifiers of Dilophosaurus are in the skull. Two crests run along the roof of the skull from the nares to the temporal fenestrae. The premaxilla and maxilla abutment is also characteristic of Dilophosaurus and many basal theropods in general. The "kink" where the two meet is also found in later Spinosaurids as well as some crocodiles and represents a weakened connection between the two jaw elements. Despite the popular image of a dinosaur with a transparent hood, like that seen in Jurassic Park, there is no evidence that indicates such a hood existed. There is also no evidence for the venomous nature of the silver screen Dilophosaurus; Michael Crichton took complete ownership of the invention of the two ideas. Dilophosaurus was, however, a rather interesting basal theropod, and a fairly hefty one at 23 feet (7 meters) and up to 2,200 pounds (1,000 kilograms).

Popular Because It's Popular

Admittedly, almost no one would have heard of Leaellynasaura if not for its role in Walking with Dinosaurs. Since that time any bland appearing ornithopod has been in danger of being labeled Leaellynasaura. Somehow, despite all of this attention, our small dinosaur does not appear across genres very often. Its depiction in books is limited to a few books about Australia and polar dinosaurs with very few exceptions; notably Lita Judge's How Big Were Dinosaurs? shows Leaellynasaura playing with penguins in a well written children's context. A modified model appears in Zoo Tycoon clearly based on illustrations by Matt Martyniuk.

What Large Eyes

The eyes of Leaellynasaura are thought to have been quite enormous, given the size of the orbits of the skull. Proportionately the orbits, and therefore the eyes, are quite a bit larger than most other dinosaurs that have been described to this point in time. The point of large eyes is, probably without needing to be said, to see better in lower light conditions. Polar winters, having longer periods of darkness, would have required animals to possess many specialized adaptations like enlarged eyes in order to successfully survive in the darkness. Without adaptations like these the ornithopods like Leaellynasaura, such as Muttaburrrasaurus, would have had to migrate away from the Antarctic Circle. More sensitive eyes, in addition to unknown adaptations of the softer anatomy that have not been preserved, allowed Leaellynasaura to take advantage of the nearly vacant polar stretch of Australia during the winter season. Predators were mainly represented at this time by smaller forest dwelling theropods like the generically named "Dwarf Allosaur"; which to this point is highly speculative and without solid evidence. It is logical, however, that some predatory dinosaur would have been able to withstand the winter conditions with similar adaptations to Leaellynasaura.

Written Leaellynasaura

The accessibility of some papers is better than others. The accessibility of free results for Leaellynasaura is one of those conundrums that ends in disappointment; not that there are not papers out there, it is just that they are nearly all well about the $30 mark. Scientific American, thankfully, bucks this trend a little by making an issue with references to Leaellynasaura and other Antarctic dinosaurs available for only $8. The Journal of African Earth Sciences is another place where we can find the importance of Leaellynasaura in writing. This time the article was pertaining to the significance of Gondwanan polar dinosaurs in the history of dinosaurs as a group. Taylor and Francis, probably not surprisingly today, takes the prize for most expensive articles (they are cheaper in some journals so please do not assume I hate Taylor and Francis). Coming to us at $44, the article reexamines the holotype of Leaellynasaura and addresses doubts and worries concerning the relationship of the skull and body skeleton of the holotype. As with any potentially volatile situation, I would not like to make assumptions on the outcome of any article I have not been able to read in full, but considering that Leaellynasaura is still considered a usable name it is fairly safe to assume that the doubts were confidently negated by the article.

The Dinosaur of the Week Walks

This is one of those days that the movie gets to do the talking for us. Enjoy this episode, if you have not previously, of Walking with Dinosaurs:

Parts 2 and 3 can be found from this part.

Snow Covered Forest for Kids

Leaellynasaura is one of those types of smaller dinosaurs that people, for lack of a better term, consider adorable. Not much needs to be said in addition to showing the links for the day honestly, considering that Walking with Dinosaurs has done a rather good job of describing Leaellynasaura. KidsDinos has a nicely shortened and concise web site for Leaellynasaura. Enchanted Learning has a good site with a fairly nice illustration, thankfully. There are few times we get to mention Enchanted Learning having a quality illustration to color, so I enjoy getting to say that today. There is also the below coloring page that depicts a very angry looking Leaellynasaura.

Furred Polar Brrrrs

Leaellynasaura was a polar dinosaur. The area in which Leaellynasaura lived was well below the Antarctic Circle meaning that during part of the year, at least, the Antarctic winter caused that area of Australia to be darker and colder for a longer portion of the day. To combat this the long tailed and large orbited Leaellynasaura could have certainly been feathered, or at least covered in a fine downy coating of adaptive filoplumes. Though, to my knowledge, no evidence of these filoplumes has been recovered with the remains of Leaellynasaura. Ornithopods with this kind of covering, and we may find the evidence for it, then push the origin of filoplumes into a rather odd direction marking it as either independently evolved in multiple lineages (Theropods, Marginocephalians, and then Ornithopods at least) or being derived from a much more ancient common ancestor than previously assumed. Regardless, a furry Leaellynasaura running through the snow covered darkened forests of Antarctic Australia foraging for what little food is available are pretty fantastical and intriguing. It is quite unique as well, of course; thinking of dinosaurs as snow dwelling dinosaurs. The majority of images of Leaellynasaura portray a scaled ornithopod and a feathered, or down, covered version is quite fantastic.

Next Oldest Post

Nobu Tamura

Continuing in the revamped original 8 posts this week is Leaellynasaura. Another Australian dinosaur from south of the Antarctic Circle (look back to Atlascopcosaurus), Leaellynasaura amicagraphica was named after the daughter of Tom Rich and Patricia Vickers-Rich (Leaellyn Rich); our intrepid Australian dinosaur discoverers of countless specimens. The specific epithet references the Friends of the Museum of Victoria and National Geographic, which have helped finance  Australian paleontology for years. Two nearly complete skeletons and two fragmentary skulls as well as multiple other fragmented skeletons have been recovered. The tails and orbits of Leaellynasaura are defining characteristics of the small ornithopods and represent highly adaptive evolutionary characters of the skeleton suited for the polar ecosystem in which they lived. Small forest dwelling polar ornithopods are the topic of the week here, be prepared!

What Has Not Been Mentioned

This week has been fraught with popular culture references already; it almost seems like too much to devote an entire post to popular culture. However, I have barely scratched the surface of how many times Deinonychus has appeared somewhere on television or in the movies. Accepting that the dromaeosaurids of Jurassic Park are meant to be based on Crichton's description of Deinonychus (as Velociraptor) we can say that Deinonychus has appeared in at least 4 feature films; it is very safe to say that the 4th installment will have some of these fellows floating about. There are also appearances in numerous documentaries, television shows, cartoons (including Dinosaur King and Dinosaur Train), and even video games (both Zoo Tycoon and Spore models have been made). It has also appeared in many books, as many different toys, sometimes as a plush animal, as models, statues... really there is too much to link today, so I have not created links for all of these categories. Deinonychus is a very prominent dinosaur in the dinosaur figure arena. Most of the plush dinosaurs have been fairly inaccurate; this is what I would love to see as a plush version:

©John Conway

Something We Often Missed

©Emily Willoughby

Deinonychus was a tad slower than we have been led to believe. Ostrom (1976) stated that the foot-tibia ratio of .48 indicated that Deinonychus was not much faster than contemporary dinosaurs. Some estimates put its top speed at around 6m/h; still plenty of speed to run down a human being of course. It also ranged a lot further than previously thought according to a hypothesis based on teeth from Maryland. These teeth were described by Lipka (1998) as being near deinonychid if not from Deinonychus itself. Speaking of those teeth, the bite force of Deinonychus was found to be relatively weak; recall papers from yesterday. They were short recurved teeth designed for tearing flesh, but they were weakly rooted and the force of bite was not sufficient to be the main predatory apparatus of Deinonychus, meaning that the feet and hands were most likely responsible for the killing of prey items and that the muzzle most likely acted in coordination with strengthened arm muscles and sometimes weight, while standing on its prey, to aid in the tearing of flesh while dining on its victims; not unlike the feeding Deinonychus in the Emily Willoughby image today.

Lipka, Thomas R. "The affinities of the enigmatic theropods of the Arundel Clay facies (Aptian), Potomac Formation, Atlantic coastal plain of Maryland." Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin 14 (1998): 229-234.

 

Ostrom, J.H. (1976). "On a new specimen of the Lower Cretaceous theropod dinosaur Deinonychus antirrhopus". Breviora 439: 1–21.

Writing About the Terror

©Emily Willoughby

The definitive description of Deinonychus material was penned by John Ostrom in 1969 and was published in that July as a 172 page edition of the Yale Peabody Museum Bulletin. Description of the materials are rigorous and make up nearly 135 pages of the bulletin with only about 20 pages discussing the habits and placement of Deinonychus. A more in detail description of anything would be difficult to find, but our vast knowledge of the skeletal material and composition of Deinonychus comes from this absolute tome. Since that time there have been many other studies of Deinonychus including predator-prey taphonomy studies and studies of pack hunting and gregarious habits amongst members of the species. As noted Saturday studies have been conducted on the use of the noted and infamous claw of Deinonychus (and other Dromaeosaurids) but little mention has been made of studies concerning the forelimbs of these animals. Senter 2006 explored the comparisons of forelimbs of Deinonychus and Bambiraptor and determined a number of interesting outcomes from manually manipulating the forelimbs. One important outcome of the study is the knowledge that Bambiraptor had the ability to grasp things one-handed while Deinonychus did not have the dexterity to do so. Bite force has been calculated for Deinonychus as well, leading to a nearly completed picture of this dinosaur from head to tail and inside out.

The egg mentioned previously is, however, a "new" and important discovery. The egg is actually associated with gastralia from a 1931 dig and, as such, is not actually new, but has not been studied in depth until recently (some may be able to generate the full pdf through EBSCO).  The egg is small and crushed, but shares many characters with known theropod eggs and is confidently placed between oviraptorid and troodontid egg characters, making its likelihood of being representative of Deinonychus, and therefore one of the first recovered Dromaeosaurid, eggs much more likely. Preservation of the shell itself is considered to be phenomenal and the images taken from the egg by various means including high resolution microscopic images, are astounding. The fact that the authors determined it to be associated with the adult skeleton makes the find that much more remarkable and, with certainty, we can now say that we have recovered the first Dromaeosaurid (and Deinonychus) incubating an egg as well as the first egg of its kind. It makes the image at the top of today's entry seem that much more relevant.

Movie Star Here

Slightly larger than they should be, and under the misnomer of Velociraptor, dinosaurs based on Deinonychus but the size of Utahraptor pepper all of the Jurassic Park movies. Understanding the idea of Michael Crichton and being quite happy with the fact that he used a synonymic name that was, by the time of the movie's release, outdated and overturned, I am quite okay saying that Crichton's "raptors" were as accurate as he intended them to be in his book. Bearing that in mind, look at the "raptors" of Jurassic park in the way they were intended to be portrayed:

Also, one of my favorite quotes from the book:
“Hammond whined. ‘But what are you going to do to my animals?
‘That’s not really the question, Mr. Hammond,’ Muldoon said. ‘The question is, what are they going to do to us?’” (p. 303).

Also, for a slightly more updated look, check out how Deinonychus was portrayed in the BBC show Primeval:

Dromaeosaurs for Kids

Deinonychus has many sites that relate information at lower, middle, and higher reading levels; one of the many perks of being a more popular dinosaur I suppose. KidsDinos hits the lowest level readers with concise and pretty accurate facts while the middle level readers in your house can fairly easily read Kids Dig Dinos, though be aware that some of the facts presented are a little incorrect or exaggerated. The highest level kid related page we have today is New Zealand based Science Kids, but it is a short read also. Just to wind up today. There is a Dinosaur Train episode featuring Derek the Deinonychus and there is also a wealth of coloring pages.

Climbing and Slashing

Artist Unknown

For the past few years there has been some discussion here and there concerning the use of the extra large pes claws of Dromaeosaurids, particularly important to us of course, is the use of these claws by Deinonychus. The original idea for the large claw of Deinonychus is that it is used in disemboweling and killing prey items. In this illustration that claw is being used a strike against a hadrosaur's neck. Usually the strike is depicted as being directed toward the belly of the animal, but the neck would be just as vulnerable to attacks. This mode of use has been studied since the debate began not too long ago.

©John Sibbick

As this slightly older illustration of Deinonychus shows, one of the thoughts behind the the use of the claws was that it could be used to aid the gracile hands in grasping and holding prey. None of the animals in this illustration are using their pes claws for anything other than grappling with their prey item. In this manner of hunting they are using their hands and mouths to wear down the Iguanodontid that they are attacking. This manner of attacking is relevant to the second argument for use of the pes claw by Deinonychus.

Photo by Davide Meloni

One of the arguments for use of the claw has stretched the traditional boundaries of thought concerning the oversized foot claw of Deinonychus. In 2006 Manning et al fully explored the concept of Deinonychus claws as large climbing tools rather than as weapons of destruction and death. Climbing and grasping ability as well as the ability to use this claw as a weapon of disembowelment were tested using analyses of morphology and a robotic model by the researchers in question. All of the analysis done determined that climbing and grasping were far more likely uses of the claw than a disemboweling strike. The use of the claw in climbing could have serious implications in the generation and evolution of arboreal-terrestrial gliding flight and eventually powered flight.

First Step Backwards

©Nobu Tamura

As promised a week or two ago, I plan to go back over the oldest list of dinosaurs I covered prior to the inception the blog/Facebook page devoted directly to this pursuit of knowledge and education. The first dinosaur that I covered in that respect was a well known and loved dinosaur: Deinonychus antirrhopus. As the face of Jurassic Park (yes, the raptors are based on Deinonychus, though Michael Crichton referred to them as Velociraptor antirrhopus, a synonym used during the late 1980's by Gregory S. Paul most notably in 1988's Predatory Dinosaurs of the World) and the usual image conjured up by the word "raptor" these days, Deinonychus is a much revered dinosaur and the subject of many fables or half truths as well. Officially named and described by Ostrom in 1969, Deinonychus remains are actually known from long before that, though they were falsely attributed to a larger theropod with a different tentative name (Daptosaurus agilis) by Barnum Brown in 1931 while working on Tenontosaurus. Thankfully the very fragmented remains were not described by Brown and the name did not stick; Ostrom instead decided upon Deinonychus, meaning Terrible Claw (antirrhopus means "counterbalanced" and references the stiffened tail). Since the 1960's many other remains have been recovered including, in 2000, what is thought to be a Deinonychus egg, though the results of the dig and identity of the material are, at the moment, unknown to myself (I will look into this of course). This should be a fun dinosaur to cover that I have hitherto not covered with a wider audience, so I hope this is a good kickoff to my retro list!

Popularity Island

©Cheung Chung Tat

We saw the painting above illustrated in a time lapse video on Monday. We have also seen a lot of news articles about Europasaurus including this short National Geographic blurb about Europasaurus  and bone growth. There are not a lot of video game references or anything else of that nature. There is some pretty fantastic sculpture out there. Notably Hirokazu Tokugawa's piece of art is very remarkable. The face is highly detailed and really quite strange looking; it is very unique in its expression and almost alien.

Shrink Wrapped

©Gerhard Boeggemann (His site is not working lately, so it is not linked)

Hypotheses from Sander et al. (shared Tuesday) state that something like Europasaurus would have become "rapidly dwarfed" after its habitat began to shrink rapidly around it. There is the idea that Europasaurus and other island dwelling dinosaurs immigrated or were washed ashore upon islands after tidal waves or some other sort of calamity. This could have happened and a rapid, occurring in only a very few generations, evolution could have forced animals like Europasaurus to begin to "shrink" rather quickly. Shrink is the wrong word really; selection favoring smaller members of the species is a more appropriate phrasing. Should this "shrinking" selection have occurred over a much longer timeline, however, the results would have been similar if not identical. A longer timeline could be the result of changing habitat limits; rising water levels or increased erosion lowering landmasses, shifting of landmasses, earthquakes, etc. Any number of interactions possibly created the islands on which Europasaurus lived. Paleogeographic and paleoecological studies have begun to explain how these islands came about and more and more miniaturized species are being discovered as time progresses; Balaur, Magyarosaurus, Telmatosaurus, and Europasaurus are only a handful of dwarfed species. The dwarfism of Europasaurus is exceptional though in that Macronarians were some of the largest animals to ever walk the Earth and a dwarfed species of such large animals are quite intriguing.

Reading A Lot About A Little

©Nobu Tamura

Europasaurus, for all of its small stature, is a fairly widely read dinosaur; meaning that people write about it quite often and it is therefore read about globally, not that the dinosaur itself read a lot of literature. An article in Systematic Paleontology discusses the postcranial axial skeleton of Europasaurus in a fair amount of detail, if you can get a copy of it for yourself. Old news articles are usually a welcome source of information as well. This Geotimes article discusses the "newly discovered" Europasaurus and gives the small dinosaur a short but emphatic introduction to the world via a non-peer reviewed entry into the literature of the world without being too sensationalist; as the media has a tendency to do with dinosaur news. I typically dislike posting a search result, it happens from time to time, but there are a few pdf's in the search for Europasaurus that cannot be linked as they open directly from the search. I recommend Sander et al.'s supplementary information (Geology and taphonomy of the Langenberg quarry locality) and at least inspecting the abstract of Bolecsek and Wings here (Europasaurus holgeri–the dwarfed dinosaur from the Late Jurassic of Germany).

Europasaurus Time Lapse

I found two videos that are time lapsed and pretty interesting. The first is of a painting of Europasaurus which is fantastic.

The second video is a time lapse of the preparations of a Europasaurus fossil.

German Resources

We have good English resources today from the London NHM as well as National Geographic making Europasaurus an international star for children. The home state, Germany of course, also gets in on the Europasaurus fun in the Dinosaur Park of Rehburg-Loccum in the Neinburg district of central Germany. The park hosted an art contest for Europasaurus not too long ago. One of the results of this was some art that can be used as a coloring page:

Looking at Europa

©Paulo Marcio

This image has been featured before here. It was featured back in March of 2012 in a discussion about Germanodactylus. This week, of course, we are highlighting the other animal (not the fish or lizard) that are seen here. We can tell, assuming that the Germanodactylus is not enormous, that the sauropods they nearly rival in size are rather small. Europasaurus was a small sauropod resulting from insular dwarfism, the same phenomenon that created the likes of the Sicilian Dwarf Elephant and Balaur bondoc the Romanian Maniraptorid discovered only a few years ago. The small size of these animals results from generations of adaptation that lead to a large dinosaur that was large enough to still be a large dinosaur but small enough to not eat all of the limited vegetation on the small islands. Dinosaurs this small in proportional situations are almost funny looking, but it is important to see them in a relative size to other animals when it is claimed that they are miniatures of their relatives.

©Andrey Atuchin

Other illustrations, however, barely show the relative size of insular dwarf species. If we assume, regardless, that the small pterosaurs to the right and in the background are the same or similar in size to the Germanodactylus shown in the previous illustration then this must be an adult where the previous illustration was showing juveniles. Even at an adult size this is a rather small dinosaur, especially for a sauropod. The close relationship with Brachiosauridae is fairly evident in this interpretation as well especially in the posture of the animal, its neck, and the makeup of the skull of the little sauropod.

Big Nostril Lizard Foot

Picture by Nils Knötschke

Latin and Greek roots make for some rather fun to say dinosaur names and hierarchical categories. The macronarian sauropods of the Late Jurassic and Cretaceous were one such group of funny named animals; macronarian sauropod effectively translates to "Big nostril lizard foot". One member of the group, at the basal end of the family tree, was Europasaurus holgeri (meaning European lizard of Holger Lüdtke, who discovered the first fossil remains). This macronarian taxa is slightly more derived than the North American Camarasaurus but less so than Brachiosaurus and is therefore considered the sister to Brachiosauridae. The chief character marking Europasaurus as more derived than Camarasaurus is the resultant size of the body due to insular dwarfisim. That is correct ladies and gentlemen, we have here a "tiny" sauropod dinosaur. Weighing in at somewhere between 1,000 and 2,000 pounds and ranging between 5.6 and 20.3 feet (1.7 and 6.2 meters) 11 individuals are known from the initial quarry at Langeberg near Goslar, Lower Saxony (that is in central Germany for the geographically stumped). The idea that central Germany was once comprised of many small islands with dwarf sauropods inhabiting those islands is pretty funny, unique, and very interesting.

Turkey Day Tribute

Compsognathus is a good little dinosaur. It has been an interesting dinosaur to discuss and research. I wish to keep things short today as I have a lot of Thanksgiving related things to do and so too does the American audience. However, Compsognathus is so popular in popular culture that I feel it is of great importance that I need to share the above Spore creature, a plush dinosaur from a friendly Finnish artist , and this wonderful image of what a turkey wing could look like if it came off of Compsognathus or another theropod:

Grasping Hands For Grabbing You Up

©Shelley Kornatz (Eykoart)

There are a lot of things that have not yet been discussed in terms of Compsognathus, though the papers yesterday and the discussions about feathers have given us quite a lot to talk about already. Regardless, one thing that has not been mentioned and cannot be ignored is the hand anatomy of a dinosaur like Compsognathus. Early German specimens appeared to possess only two digits, while later French specimens have three digits clearly seen. The third digit, Digit I, was short and incompletely preserved in the German specimens, but the implications of the digit arrangement is that the hand appears to possess the ability to grasp prey. Grasping hands certainly appear in the Maniraptoriformes and in the earliest relatives of birds. The grasping ability of the forebears of the Maniraptoriformes are sometimes used to differentiate theropods as well. Regardless of how the character is used, it is fairly evident in Compsognathus and a lot about the diet can therefore be conjectured at including the ability of the dinosaur to grasp and eat its prey rather than having to relay on jaw muscles and teeth alone.

All the Papers

©Karola (Caimryo)

Almost "turkey day" here in the US (strange how the colloquialism has become solely about a food that was possibly not even present at the historical Thanksgiving feast), and what better way to celebrate than reading papers about the great (x 15 million, give or take a few generations) grandparents of modern turkeys? I like to think of the following list of reading material as following the bouncing Compsognathus literature, hence the use of the image above. Let us not argue about the exact evolution of turkeys and Compsognathus given the previous statement but instead enjoy the original naming and description of Compsognathus, if one can read German; English translations of this are, as far as I can tell, not available. One could also read about the synonymization of C. corallestris with C. longipes in Peyer's 2006 paper. Gishlick and Gauthier in 2007 examined the hand morphology of Compsognathus and restructured our vision of the digit count ad use of the digits in Compsognathus. For those interested in taphonomy, I found a paper by Reisdorf and Wuttke that uses decay in modern domestic chickens (referred to as "Gallus gallus L.", which is a hybridized Sri Lanka Junglefowl) to describe taphonomy in Compsognathus as well as Juravenator. There is plenty to read here today.

Compy Puppets!

I am going to let the videos do the talking today. There is a puppet video as well as the I'm A Dinosaur version for Compsognathus.

Coloring and Learning

©Emily Sheldon

There are a variety of sites that offer some knowledge on Compsognathus in literature that is written for a younger audience; which we always love to see. The sites that get used the most are represented quite well today including KidsDinos and Enchanted Learning. I am far more excited about the coloring today. Share the information with those around you, but share the coloring more today, because there is a lot of it!

Staring Pretty

©NRG (a good fellow from Argentina)

Compsognathus, as a near relative of some of the earliest known feathered dinosaurs, may or may not have had feathering. These could have been fibrous filaments or it could have been downy tufts or even full fledged feathers, depending upon how long ago feathers actually did begin to develop as more highly evolved and adapted keratinous scales. Regardless, older illustrated versions of Compsognathus or those illustrations at least done in older styles, show scaled individuals. Some show them as highly active predators while others show them as simply stereotypical small dinosaurs walking about in ferns and other prehistoric backgrounds. Rarely do they appear illustrated, feathered or scaled, with any sort of anthropomorphic intelligence. In this scene it almost appears that our little Compsognathus friend is surveying the world and taking a relaxing moment. Most of the physical features of the dinosaur are obscured enough that the neck and tail anatomy are about all we can comment on in terms of the physical build of Compsognathus.

©Nobu Tamura

As far as newer versions of illustrations are concerned, the feather fibers of Compsognathus are a little debatable overall. This version highlights an early version of feather evolution with the appearance of downy fibers all along the body. The snout, feet, and hands are lacking in feathers as they would not require nearly as much insulation as the body of Compsognathus would. Physiologically, blood traveling from the body to the feet, hands, and snout would heat the blood returning to the body from veins in/from the feet. This would keep the body warm in the same way that birds keep their bodies warm while allowing their feet and beaks to remain cold. Insulation in this manner would be the practical physiological purpose of filamentous feathers like these, but additionally these feathers would be pigmented and be able to be used for display purposes.

So Small I Missed It All This Time

I've seen this before, but I cannot make out the illustrator's name.

"The compys didn't look dangerous at first sight. They were the size of a hen and walked nervously like a hen. But he (John Hammond) knew that they were venomous. Their bites delivered a slow-acting poison that they used to kill wounded animals." —Jurassic Park (novel)

Granted the above quote is in reference to the novel's Procompsognathus denizens and we are covering their descendant, Compsognathus, it is still a wonderful little quote from the novel about a somewhat understated lineage of dinosaurs. Both Procompsognathus and Compsognathus were small theropod dinosaurs with "elegant jaws" (the meaning of Compsognathus). Compsognathus consists of a single species, C. longipes, though a now synonymous species was once purported to exist as well (C. corallestris). The originally described size was slightly smaller than the full grown adult size of just over a meter or about 3.3ft. The reason for this is that a juvenile specimen was initially described as an adult. Regardless, at approximately a meter long and between 1.8 and 7.7lb (0.83 and 3.5kg) Compsognathus was the smallest non-avian dinosaur known for many years. An obligate biped, Compsognathus was quite gracile and agile, able, more than likely, to chase down many smaller prey items like large insects and small mammals and lizards. Though often depicted (in Jurassic Park related media primarily) as pack hunters, no evidence of this behavior exists that has been documented. Feather coverings, though not depicted often, may have been present on living members of the species, as they are closely related to known feathered dinosaurs such as Sinosauropteryx and Sinocalliopteryx.

Exciting Times!

There is little to discuss in terms of the popular culture impact of our small basal Ornithopoda friend Atlascopcosaurus this week. As such, we will discuss the world in which this dinosaur lived. Atlascopcosaurus was discovered in Dinosaur Cove's Eastern area in 1984. 104 million years ago the Dinosaur Cove area was closely associated, geographically, with the landmass of Antarctica and well below the Antarctic Circle. Current research indicates that the areas within the southernmost area of the globe near the Antarctic Circle potentially occurred dark and light seasons. More famous denizens of this light and dark season land include Muttaburrasaurus (the taxon in which Atlascopcosaurus is sometimes considered a member due to its fragmentary nature), Leaellynasaura‎, and even a carnivore simply referred to most often as Dwarf Allosaurus. It is unfortunate that more of this little dinosaur has not been recovered (and also that it actually be a nomen dubium that belongs to another species). Regardless, the adaptations to light and dark seasons that could potentially be seen in this taxon would be wonderful. Should more ever be discovered it will tell us a lot about the dinosaur and it will definitively answer the question regarding the position of the dinosaur itself.

Once A Hypsilophodont

©Robinson Kunz

Originally diagnosed as a middle of the group Hypsilophodontid, Atlascopcosaurus, has since been reassigned to the honored position of one of the basal-most Ornithopoda. Hypsilophodontidae would still be recognized as the family to which Atlascopcosaurus is assigned had it not been deemed paraphyletic and effectively banished from dinosaurian systematics. Regardless, as a basal member of the Ornithopoda Atlascopcosaurus possesses many characters that define the clade later on. Bipedal herbivores, Ornithipoda like Atlascopcosaurus, possess predentary beaks and occluding grinding teeth in a distinctive cheek region along the maxilla and dentary. They also should, remember that Atlascopcosaurus remains are exceedingly fragmentary postcranially, possess ossified tendons along the caudal vertebrae that stiffen the tail, making structurally very much like a cantilever bridge; it provides stability and support to balance out the center of gravity oriented in the upper thoracic area. The nearly horizontal body position is well exhibited in this illustration, and the feathering or filamentous fibers, are a fairly certain reality as well at this point. Small basal members of Ornithopoda are no longer so bland as they used to be thankfully.

A Book Star

Atlascopcosaurus has not made a significant impact, overall, in the peer reviewed scientific publication world. It has, however, appeared in a number of books as passing information and even as a key character. Some of these books may have been mentioned in prior entries given that they have information contained with that discusses other Australian dinosaurs. These include books like Minmi and Other Dinosaurs of Australia as well as World's Smallest Dinosaurs. Rich and Vickers-Rich published the initial naming and describing paper, as previously stated, but they also co-wrote a 1999 paper which was much more about the Hypsilophidontids of Australia as a whole; the abstract can be found through this link. Chapter 18 of Dinosaur Systematics describes the basal Ornithopoda and here too Atlascopcosaurus is touched upon. The Witmer Lab at Ohio University hosts a PDF version of this chapter, making it available online; Dr. Witmer is a co-author of the chapter.

Australia in Motion

Atlascopcosaurus is not a vividly in motion Australian dinosaur. There are few resources that show Atlascopcosaurus in motion adequately but there is a tribute video, and that is a step in at least a somewhat progressive direction. Beyond that there really is not much in the way of videos. Below is the tribute video that shows Atlascopcosaurus, however briefly it is; it is a video highlighting all Australian dinosaurs afterall.

Atlascopcosaurus and Little Fact Pages

Atlascopcosaurus shows its face rarely if at all in terms of reliable internet sites. This is not much different from the types of things that exist to present on normal Sundays; in a perfect world there would be far more sources for every animal for younger readers. However, today the only quality links, and thankfully they are quality links that happen to exist, come to us from About and the NHM in London. I also took the liberty of clearing out a rather blank image to begin with for coloring purposes.

Blank Faced Ornithopods

©Karkemish (via Deviantart)

Today I have decided that we will only have on illustration. There is a reason to such madness. The fragmentary nature of the discovered cranium makes it difficult to illustrate or even describe what the post cranial skeleton looks like. Therefore, any recreation is little more than an approximation based on a generalized Ornithopod body plan. Some studies have gone as far as to determine that Atlascopcosaurus is a nomen dubium (none cited in the Paleobiology Database though this is where the original claim of nomen dubium originates) while others have claimed that the likelihood of a relationship between Atlascopcosaurus and Muttaburrasaurus requires a redefinition of the Iguanodontia including the designation of the family Muttaburrasauridae. Atlascopcosaurus is a much smaller animal than Muttaburrasaurus but the likelihood of a parallel evolution of body shape within the closely related Australian Ornithopods is more than likely what most illustrators and descriptors are basing their images on.

The Riches

The world owes a fairly big chunk of its knowledge of Australian dinosaurs to Tom and Patricia Rich (more correctly known as Patricia Vickers-Rich). Using the equipment of a company known as the Atlas Copco Company in 1984 (naming and describing taking place during 1988 and 1989) the duo dug out and named a dinosaur after their tool company! Additionally, the specific epithet honors the state manager of Atlas Copco, and an assistant in the dig, William Loads. Therefore, the name Atlascopcosaurus loadsi, was coined in the description of this dinosaur. A small basal Ornithopod dinosaur, Atlascopcosaurus is known from fragmentary cranial skeletal material and not well known at that. Since the postcranial material is missing, not much is known about the overall shape of these dinosaurs other than that they were basal bipedal Ornithopods, and this is hypothesized from the skull. Difficult weeks are a lot of fun around here!