Some Short Anatomy

©Gaston Designs

The arms of Falcarius are where the name came from, so we expect them to be pretty stunning. The large claws of the arm are just that; they are quite extraordinary in the world of an herbivorous dinosaur. Most herbivores either use size or speed to protect them from predators. Many have other forms of protection, such as safety in numbers, but the large claws of Falcarius would certainly have made formidable weapons for protection against predators. Additionally, the claws are situated much like those of a sloth, and as such, are fairly ideal for pulling branches to the animal rather than grabbing and grasping.

The teeth of Falcarius are rather peg-like. In some other animals, like Diplodocus, we find these sorts of teeth and they are mainly for sheering leaves off of the twigs and branches from which the dinosaur fed. Because of this it is also highly likely that Falcarius ate in a very similar manner. Use of the hand like that of a sloth, for pulling down branches, while the teeth strip the leaves from the plant. The teeth are not designed for crushing and chewing plant matter in a highly efficient manner. There are a few teeth that appear to be for crushing plant matter, but they are very few and more toward the posterior end of the mouth. This probably entails the use of a gizzard in the digestive system, though as yet we do not seem to have compelling evidence of this organ structure.

Therizinosaurs!

Therizinosaurs are some of the creepiest dinosaurs I can think of. Our dinosaur this week, Falcarius (One species: Falcarius utahensis), is considered a valuable transitional discovery between other theropods and true therizinosaurs. Study of this Utah discovery in conjunction with the recently discovered Beipiaosaurus from China have allowed researchers to discover a lot more and draw a lot more logical conclusions about the evolution of the family of therizinosaurs. Falcarius, meaning "sickle" in Latin, was named for its high curvature claws present on its hands. A fairly long dinosaur, Falcarius has quite a stretch at the neck as well as quite a reach with its forelimbs. Typical therizinosaurs are assumed to be some of the only theropods that are obligate herbivores; ornithomimids are the other major family of theropods thought to be partially herbivorous but are proposed to have been much more omnivorous in nature. Falcarius was discovered by Larry Walker in 1999 in the Crystal Geyser Quarry of eastern Utah. James Kirkland, who we mention a lot in Utah related paleontology, was called in to head the geological survey team in 2001 that began to recover the bones of this dinosaur from the quarry. By 2005 a couple of thousand specimens had been recovered comprising the total remains of at least 300 individuals. Since that time the number of specimens has increased to over 3000 in the original quarry and a second quarry has been discovered to also contain specimens of this animal. The name was officially given to the dinosaur in May 2005's publication of Nature by Kirkland et al., which we will visit later in the week.

Picture by Paul Fisk. Mounted at the Utah Museum of Natural History.

Othnielosaurus Waited All Afternoon

Paleontology Museum of Zurich

I slacked a little bit today, and I apologize for that my friends. Othnielosaurus was more popular as Othnielia than it ever has been as Othnielosaurus. Under its new designation as Othnielosaurus this dinosaur has not gotten anywhere near as much recognition. Part of the difference is that Othnielia was a recognized name for 30 years and was renamed during the height of the Dinosaur Renaissance. Under that name many documentaries mentioned the dinosaur as well as many papers/articles, and books. Dinosaur toys are still more often associated with Othnielia that with Othnielosaurus. The dinosaur has made it into the world of video games under both names; it has been created and displayed in Spore by different creature creators under both names. Othnielia did appear as a toy under the Discovery Kids brand of "educational" dinosaur toys a few years back.

Othnielosaurus Confused

Othnielosaurus is a very confused dinosaur, as we have seen this week. Most of the confusion associated with Othnielosaurus is due to the fact that the name and assignment of the remains has been changed so many times during the history of our knowledge of this species. The reason is that, as we have seen, different reviewers of the material have had different ideas about the associations of the animal with other animals. Overall, this is how the history of the dinosaur's names goes:

Species recognized in each of the genera to the left are listed with authority.

Laid out like this it is not too confusing really, but it is very easy to see how and why it can get confusing rather quickly. Technically Othnielia still exists, but the fragmentary nature of the single femur that Galton still recognized as belonging to Othnielia relegates the genus, as Galton himself even recognized, to the status of nomen dubium. Therefore, Othnielosaurus is the only genus of those above that is officially recognized as valid at the present time. In the future it is probable that Othnielia will be officially classified as a nomen dubium or be revived by the discovery of new remains.

Othnielosaurus in Writing

Many papers have been written about, or mention, Laosaurus, Othnielia and Othnielosaurus. The key papers that describe and assign the animals through time into ever smaller groups are the most important papers though. Marsh's original 1877 piece describing what he called Laosaurus is of the utmost importance as it provides original descriptions of the remains of Othnielosaurus. Likewise important is CW Gilmore's 1909 description of an addition to the family; Laosaurus minimus. Both articles are difficult to find copies of, and your best bet honestly seems to be inter-library loans, as the internet does not have scanned copies hidden in it anywhere it seems. In 1977 Galton reassigned both L. consors and L. gracilis to Othnielia rex and redescribed the remains of the two species. 30 years later, in 2007, Galton again re-examined the remains and reseated the genus as Othnielosaurus. Both of these writings are of importance. The 2007 writing is a part of a book called Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs edited by Kenneth Carpenter while the 1977 article was published in Nature, and is therefore hard to come by as well online.

Othnielosaurus Hunted

Once again Othnielosaurus has not shown up in searches due to the change in name. However, Othnielia still turns up results on this happy little Monday. Strangely enough, the results it turns up appear to have landed us in two time frames; Jurassic and Cretaceous references are both present for Othnielia in the one documentary in which it seems to appear. The documentary series in question is Walking with Dinosaurs, and we know from experience here that the experience of Walking with Dinosaurs is that it is sometimes inaccurate. Othnielia/Othnielosaurus is hunted in two episodes of the series at large. In one episode it is approached by a Cretaceous Utahraptor in what is now Europe while in another episode it is hunted by Jurassic Allosaurs in North America. Unfortunately, clips from episodes of shows like Walking with Dinosaurs are slowly getting weeded out from the internet due to copyright laws, so it is getting harder and harder to find quality clips. Stills from the shows exist though and I can easily share those, as I have done today. As a caveat with this image though, it has also been seen labeled as Dryosaurus, Hypsilophodon, and probably others.

Finding Othnielosaurus

In 1977 Peter Galton changed Nanosaurus to Othnielia. In 2007 Othnielia was again changed by Galton to Othnielosaurus. This made finding kids websites a little more of a chore this morning as I had to search multiple names to find the correct dinosaur. When I did find what we are looking for though, I found a lot of good websites for kids, just under an older name that has not been changed to the current name quite yet; widespread acceptance of Galton's reassignment of all of the remains to Othnielosaurus is not yet apparent. Anyhow, Othnielia, which would have been almost indistinguishable from Othnielosaurus at any rate (a good discussing point with young paleontologists), has pages dedicated to it at KidsDinos, Animal Planet, and Enchanted Learning; a long and short version are both available. Coloring pages for today seem to be lacking, but the conversations generated from the fact pages and a discussion of why the name changed may just fill the entire day with paleo fun for the young enthusiast, and that is what Sundays are all about around here anyway honestly!

Omnivorous Herbivourous Carnivore

Marsh's Laosaurus

The typical configuration of hypsilophodonts is that of an herbivorous bipedal dinosaur running swiftly through the underbrush and nibbling at the leaves on the forest floor. Marsh's original interpretation was the opposite; he envisioned a small carnivore rushing around the underbrush snatching up small mammals and insects. However, he also envisioned Laosaurus as a tail dragging bipedal carnivore, as was the norm of many paleontologists in the 19th century. Tail dragging eliminates the ability of any animal to jog off into the underbrush of a forested canopy. The sub-rectangular head is full of teeth that, while they could be used by a carnivore, are far more likely to be found in the mouth of an herbivore or an omnivore; some of the teeth would be fairly out of place in the mouth of a carnivore.

©Nobu Tamura

A more horizontal position for the spinal column is also a little more pleasant to look at as the upright Othnielosaurus looks a little too rigid for a living, moving animal. An Othnielosaurus that is somewhat bent over can forage a little bit faster and is already in a pretty good position to sprint off to safety with very little notice. The ability to sprint with little notice is important for a dinosaur that has very little natural defensive ability outside the ability to bite at would be attackers, as any animal with teeth can do.

Othniel Honored

Running herd cast at the Denver Museum of Nature and Science; Tad Williams

In 1878 Othniel Charles Marsh named a small ornithischian dinosaur Laosaurus consors; "kindred stone lizard". Since that time other species were attributed to Laosaurus by Marsh and Gilmore but subsequent and current research has determined that Laosaurus is a nomen dubium. Instead, the basal hypsilophodont Othnielosaurus consors has been renamed in honor of OC Marsh. As of 2007, the most current analysis of Othnielosaurus, Peter Galton has upheld a 1990 paper by Bakker et al that placed Othnielia, another previous placement of Othnielosaurus, in a position of being more basal than the most basal hypsilophodonts; in other words Othnielosaurus is primitive enough that it may be a common ancestor, a splitting point, of hypsilophodonts and another group of animals. Current cladograms, however, simply place Othnielosaurus at the base of a split between Thescelosauridae and Hypsilophodontidae, making them more basal than both but not a common ancestor from which the families are both derived; systematics and cladistics gets confusing rather quickly sometimes. Regardless, this is a rather basic ornisthischian dinosaur, the kind that looks like a large and active lizard and does not stand out like a Triceratops or a Dilophosaurus from the rest of the dinosaurs.

Hard Being Popular

One of the worst things about ceratopsian skeletons is the general lack of post cranial material. Generally all ceratopsians are illustrated, sculpted, and modeled the same exact way post cranially due to this lack of information. Therefore, a lot of illustrations, etc. that are attributed to an animal like Pentaceratops are not always of that animal (images geared toward children are the absolute worst at misidentifying ceratopsians). Despite this and the sheer number of returns in a search for Pentaceratops, the popularity of Pentaceratops is not over exaggerated by misidentifications; it is in fact a rather popular dinosaur in popular culture. Pentaceratops has been depicted in Dinosaur King video games as well as cartoons (both episodes in which Pentaceratops appears are hosted by 4KidsTV on YouTube) and in other games, such as Spore, where it was created or added in by players of the game.

Pentaceratops has also been molded a number of different ways as toys and action figures; the ability to be posed being where I differentiate the two. Toys tend to be a little more often scientifically accurate models, whereas action figures are almost always gaudy representations of a passable version of the dinosaur in question.

Toy/model

Action figure

The Big Frill

Holotype designated by HF Osborn, 1923

Measuring approximately 10 feet from the anterior of the premaxilla to the posterior end of the parietosquamosal frill, Pentaceratops had a head about as long as the largest known adult male lions; the largest known measured 12 ft, but many have been recorded around 10ft long including their tails. The horns of Pentaceratops were rather large, as we have seen and discussed previously. Technically Pentaceratops, though being called a five horned dinosaur, has only three horns. The protuberances along the cheek are epijugal extensions and are actually only extensions of the cheeks of the dinosaur. Likewise, the "horns" at the top of the frill are epiparietal extensions of bone and are, themselves, also only protuberances of bone and not true horns. The remainder of the skull is fairly typical of a ceratopsian dinosaur with the exception of the overall size. The nasal horn swings forward and up to a point and then begins to angle posteriorly at the apex. The orbital horns also follow the gentle forward curving but instead curve extremely anteriorly at the tips rather than posteriorly. The teeth are pretty much what we expect to see in a ceratopsian dinosaur as is the "beak" that makes up the majority of the premaxilla.

Printa-ceratops

Wired Science compilation using Nicholas Longrich's skull reconstruction on right

We could spend all day today simply linking articles that are about, mention, or vaguely address Pentaceratops. There are not enough hours in the day to read all the papers I found within the first ten seconds of searching for articles to read. There are later discoveries of skulls that are described, "new" compilations of data on the dinosaur genus (from 1993), and even re-evaluations of the genus as a whole. If you can find a copy I recommend, as always, reading the original description by HF Osborn and CH Sternberg which is only 3 pages and was published by the American Museum of Natural History. I also recommend reading Longrich's paper announcing Titanoceratops ouranos from 2011. The majority agreement at the moment is that Titanoceratops is a junior synonym of Pentaceratops, and that is the key reason I would say it is important to read this paper.

Pentaceratops Movies

Movies about Pentaceratops, in a professionally done manner of speaking, are few and far between, but movies do exist. There are numerous Pentaceratops tribute videos; it is always kind of fun to see what images people grabbed and how they used them in that context despite my dislike for the music that is typically used in those sorts of videos. There are also a lot of Dinosaur King and other video game related movies floating around out there. Norman's Sam Noble Museum has a nice skeleton on display of Pentaceratops which is shared in a few videos that have been posted. The least personal of these is found below; the others are mainly home videos and, as such are a little more private even though they are posted online.

Pentaceratops the Gentle

Krispy Kreme hosted a coloring contest featuring Pentaceratops once in New Mexico; that is how popular the dinosaur is with kids in its "home state". Pentaceratops is a well known dinosaur the world over though it seems. Science Kids (the New Zealand website that shows up here from time to time), Enchanted Learning, NHM London, Dinosaur Jungle, and KidsDinos all turn up as fact pages that are geared toward children when we look up Pentaceratops in relation to youth. That makes it one of the most popular dinosaurs in terms of children related fact pages found online; a fairly spectacular occurrence to be completely honest. Enchanted Learning has links to one of their kid-drawn dinosaur coloring pages on their fact sheet, but there is also coloring available from a site called kidscanhavefun.com (equally inaccurate but "cute" dinosaur). There is little shortage of dinosaurs labeled Pentaceratops on coloring pages to be honest. All of them are slightly inaccurate, but inaccuracies, carefully approached, can lead to an enlightening conversation with any age child and developing critical thinking and the ability to compare images may be a good exercise today!

Hanging Pictures on a Frill

Adopted from Sampson SD, Loewen MA, Farke AA, Roberts EM, Forster CA, et al. 2010

Pentaceratops had, arguably, one of the largest frills (a parietosquamosal caudal extension of the skull) in its family. Chasmosaurine ceratopsians typically had larger frill areas than centrosaurs and protoceratopsids. There are always a few exceptions to every rule (Styracosaurus for example had a rather large frill for a centrosaurine ceratopsian), but it does fit as a general rule that a large frill belongs to a chasmosaur. The eyebrow (orbital) horns are also quite extensive and curved downward (the bird world would call this a decurved horn but some here may refer to this as rostrally or ventrally curved). The small nasal horn curves slightly backward but does not reach such a length that the curvature becomes highly pronounced. Fenestrations of the parietal are found in the frill which serve to lighten the bone mass, as in most ceratopsians, and the skull is joined to the postcranial vertebrae in a complex joint that allows movement somewhat like that of a ball and socket joint.

References

Sampson, S. D., Loewen, M. A., Farke, A. A., Roberts, E. M., Forster, C. A., Smith, J. A., & Titus, A. L. (2010). New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism. PLoS One, 5(9), e12292.

 

©Nobu Tamura

 When the skull is turned even slightly away from a direct lateral view we can see that the frill forms a rather large U bend in the center of the dorsal end of the frill. The small hornlets, or epiparietal horns, are turned down and forward (decurved/rostral and anterior facing). Also we can see that skin stretched tightly over the entire frill would accent the fenestrations by being "sucked" into the bony windows slightly but enough that we would be able to notice them. This theme occurs constantly in the recreation of ceratopsians and, given the idea that the fenestrations existed to lighten the bone rather than house important organs, it makes a great deal of sense that skin and other tissues above those holes would not disguise their existence by puffing outward or anything of the like.

Star Heads

©Mariana Ruiz Villareal

Technically it just means "five horned face" but most star shapes have five points, so calling Pentaceratops sternbergii a star headed animal is not too much of a stretch. The five horns mentioned are the three we typically think of on a ceratopsian skull plus two spikes lower on the skull referred to as "epijugal" spikes; these are the protrusions of bone below the orbits which extend laterally. Pentaceratops is one of the larger members of the Chasmosaurine ceratopsian.  Discovered initially in 1921 (by Charles H. Sternberg) and named in 1923 (by Harry Fairfield Osborn), Pentaceratops was initially recovered from the San Juan Basin in New Mexico. Many examples of this dinosaur have been extricated from the land since, including a rather large specimen that, at the moment, is generally considered a synonymous species but is known as Titanoceratops ouranos (more on this later). As with many other ceratopsians, Pentaceratops discoveries generally consist of only, or little more than, a skull. The holotype is a skull only find from Sternberg's 1922 expeditions to New Mexico. Sternberg did, in 1921, discover a nearly complete specimen (why the 1922 skull is the holotype and not the 1921 skeleton is something that will be explored later, potentially).

Story of Coelurus

Zander and Kevin Cannon have a knack for making dinosaurs more popular. Their cartoon studio has done an awful of lot work in multiple disciplines and over a wide variety of nerdy/geeky subjects. The book, Evolution: The Story of Life on Earth, features their combined artwork and the writing of Jay Hosler and is set in a very accessible graphic novel format. Their inclusion of a rather baffled looking Coelurus in the artwork of the book can be attributed to the knowledge of the skeleton and the fact that Coelurus has been well known for such a long time before it was accepted that the entire skeleton was indeed the remains of a single individual spread out around the quarry. Coelurus has also showed up in a few video games such as Jurassic Park III: Park Builder, or at the very least, has been modded into a few games such as Zoo Tycoon. There is not a wealth of popular culture references beyond the inclusion in those games or the book, but it is enough really. There are so many dinosaurs out there we cannot really and truly expect them all to be extremely popular.

Things I Like About Coelurus

Via the Daily Mail (Artist not credited)

From 1980 to the early 1990's Coelurus benefited from being studied again and, this time, by being recognized as itself. During this time different paleontologists looked at the different bones that had been recovered from the Como Bluff (in Wyoming) quarry known as Reed's Quarry 13. Many different skeletal aspects of many dinosaurs had been recovered from the quarry and upon inspection under the watchful eyes of the likes of John Ostrom it became apparent that many of the elements had come from the same individual but had been slightly scattered. That individual turned out to be a Coelurus adult and now is fairly complete, not entirely complete still however. The known skeleton consists of two arms from the Cleveland Lloyd Quarry (Utah) as well as pelvic and shoulder girdle elements, multiple vertebrae, a small section of mandible (probable remains), and members of both arms and legs housed at the Peabody Museum from Reed's Quarry 13. The mix up at Reed's Quarry 13 can possibly be explained by the nature of the area at the time of Coelurus' existence; a semiarid floodplain with wet and dry seasons is a good place for a dinosaur to expire in the dry season and then have its bones shuffled about in the next wet season. This phenomenon, or perhaps commonplace occurrence, is witnessed in other contemporary animals of the floodplains such as Allosaurus, Torvosaurus, Apatosaurus, and Diplodocus, to name a few.

Coelurus the Writer

Admittedly Coelurus did not write papers about itself (or have a written language itself) but there are papers out there that have been written about Coelurus. Some of these that can be found are about Coelurus bauri Cope, 1887; this dinosaur is now known, as was previously discussed, as Coelophysis bauri Cope 1889. Coelurus fragilis, however, is less well documented, but is still fairly well documented in and of itself. In fact, new finds of Coelurus have been well documented throughout time, including in 1997 in Wyoming and Coelurus has even been debated as a theropod and discussed in relation to ornithomimids. It has been included in some important works including The Dinosuria (both editions), numerous field guides (including Paul's Predatory Dinosaurs of the World), and even a few smaller books.

Little Skulls

Coelurus has only made it into a short video that I have seen discussing the discovery of a small skull that belongs to it.

The fact that a skull was found is not that amazing, but that it was fairly intact is always good for science because it houses so many more clues than a skull that is missing any important elements. As with many other videos, I really wish there was more to this and there may have been when the clip aired in an episode, but copyright materials are not shared freely by corporations, so you may have to dig on your own a bit for this one.

Little Dinosaur, Little Kids

via Arthur's clipart

Coelurus is a small dinosaur; I think that point has been made many more times than needed over the past few days. The main point of today, as always, is to share information that we can share with our younger audience. To that end, I have a good fact page for all of those kids out there that are developing their reading skills and love dinosaurs (you do not have to love them to read it though!). KidsDinos.com, one of our usual favorites, has a good and short page of fun dinosaur facts for today. Another typical entry for us today, the Natural History Museum in London, also has a short, actually a shorter, fact page to peruse for Coelurus. Coloring pages exist as well today, but the best are the image above and an image hosted by H&M Coloring Pages (not related to the store H&M).

Look at the Detail

©Kazunari Araki

First of all, that is not a set of toys or digitally created. This is a small sculpture. That in and of itself is pretty amazing. Mr. Kazunari has created sculptures for some of the largest museums in Asia, particularly Japan, and has also written books on the subject of dinosaur sculptures. He has also helped produce model kits for Kaiyodo, a Japanese model making company more famous for their WWII models that dabbles quite a bit in prehistoric creatures as well. The actual statuette (measuring 25x15x25cm) does not have the background shown here but does show Coelurus attacking a small Rhamphorynchus on an oval shaped base. How often a Coelurus would have had this particular meal is something that could be debated, but its hollow vertebrae indicate it was somewhat light skeletally meaning it may have had the speed to sneak up on a landed pterosaur provided it also had the needed stealth to accomplish that feat. Regardless, a wonderful rendition of the small Late Jurassic carnivore.

Looking for artist

The idea of Coelurus as an ornithimimid has been brought to light a few times, though not in peer reviewed discourse, to my knowledge. Rather, Coelurus is considered a Coeulrid, a family that includes many other small Jurassic and Cretaceous carnivores such as Compsognathus and Sinosauropteryx. The main shape of all three dinosaurs is quite similar. Long tails counter-balance a forward leaning running animal allowing it to accelerate, turn, and maintain a top speed with maximum efficiency for the dinosaur's hunting and escape habits. Being a lighter dinosaur Coelurus may have had the ability to climb as well; this is a fairly common sense lifestyle attribution given that the feet of Coelurus are quite avian in its design.

Coelurus in the Afternoon

©Nobu Tamura

Some days we just have busy morning. Coelurus does not mind at all. As long as I get to introduce him to everyone I strongly doubt that Coelurus would care. The genus Coelurus consists of one species, Coelurus fragilis, though it does have two synonymous names; C. agilis and Elaphrosaurus agilis. Elaphrosaurus is a rather odd name, though it sounds interesting, and I for one am glad that it was the junior to Coelurus and not the other way around (Coelurus Marsh 1879 versus Elaphrosaurus Marsh 1884). Elaphrosaurus, just to avoid confusion, has been raised since that time (Janensch 1920) as an ceratosaurine genus; more about Elaphrosaurus in the future though. Meaning "hollow tail" Coelurus' description was a product of what has come to be called the "Bone Wars" of the 19th century between Marsh and Cope. As such, it was not given much thought after it was named and described. A full year of quarrying, September 1879 to September 1880, revealed many different aspects of the skeleton of Coelurus, but the passage of time and the disassociated elements lead to confusion and the misidentification of the remains as belonging to more than one species, thus the synonymy that is present now. Cope and Lydekker also named species of Coelurus, only to have them changed later to other genera; Cope redescribing the two Coelurus specimens he had named as belonging to Coelophysis and Lydekker's specimen being transferred to Thecospondylus. Thankfully, however, all of that misinformation and confusion has been cleared today and we recognize, and know, a single species of hollow-tailed fragile dinosaur as Coelurus fragilis.

Almost Complete

Photos by Adam Stuart Smith and Stefan Schröeder, top to bottom
as seen on the Dinosaur Toy Blog

The most complete skeleton discovered in the British Isles is that of Scelidosaurus. It begs the question, then, why is Scelidosaurus not a little bit more popular, at least a little more anyhow? Illustrations have been quite numerous over the 150 years of Scelidosaurus' named existence in the knowledge of human beings, as have statues and other artistic visions (I am counting photographs of aforementioned art as well as models/toys) of the species. We can generalize and state that any really basic (i.e. dollar store) bag of dinosaurs has a small quadruped that we can say with some certainty represents Scelidosaurus; it could be attempting to represent a different but similar dinosaur, but when we are talking extra cheap dinosaur toys it almost does not matter what the model is supposed to be. There are, of course, good toys out there. There is also the one video game reference and there are books that mention Scelidosaurus, including kids books. Scelidosaurus is a fairly famous dinosaur with little popular fame, which is a bit sad when you think about it.

Completely Incomplete

Cast of the David Sole specimen.

Despite the 2000 discovery of what is known as the David Sole specimen of Scelidosaurus, there has not not been a modern description of Scelidosaurus. The David Sole specimen was discovered in England (though a cast is only on display in St. George, Utah) and is 7ft (2m) long and represents perhaps either a separate species or sexual dimorphism. This is because there is different dermal armor on the skeleton than has been discovered previously. All of the material previously was, in general, uniform in its coverings and skeleton itself. The soft tissue and Arizona discoveries along with the David Sole specimen cap off, at present, a long history of Scelidosaurus discoveries and research. They also add to an already extremely long and detailed list of knowledge about Scelidosaurus and add to that life history, which is always important to the understanding of any taxon extant or extinct. For instance, we know that Scelidosaurus had leaf shaped teeth capable and ready to crop vegetation and to puncture and crush its food rather than grinding it between teeth. We also know that, like its descendants Ankylosaurs and Stegosaurs, its armor was keeled on the dorsal sides and concave on the ventral sides. These scutes, we also know thanks to the soft tissue preservation in one of the later specimens, were covered by a layer of skin and that the amror was not on the outside of the skin.

When You're This Old...

People have written about Scelidosaurus and they have also studied it a lot. The older the dinosaur the more it has been studied would be a nice rule of thumb, but we know that is not the case. Regardless, this dinosaur does pretty well follow that ideal for a variety of reasons including its position as one of the most basal members of its group. Being the first complete dinosaur discovered had its advantages, such as the wonderfully in depth description provided by Owen in his 1863 publication A Monograph of the Fossil Reptilia of the Liassic Formations, Parts 1-3. He starts the discussion by noting that the skeleton available to him is a young Scelidosaurus and not an adult; this constitutes a very important distinction when considering the life histories of specimens. Owen was also using a lot of jumbled material, however, and a little over 100 years later, in 1968, B.H. Newman wrote a paper describing the lectotype of Scelidosaurus, Lydekker 1888 (a right knee joint/complex), as a megalosaur and calling for a new lectotype to be raised. He proposed that the skull and associated skeleton be placed as the lectotype in the place of Lydekker's lectotype. Newer research and discoveries have been conducted as well. In 2003, for instance, soft tissue was discovered and publicized in a Scelidosaurus find. Not as new, but still of great importance to the study of Scelidosaurus is the discovery of Scelidosaurus remains in Arizona in 1989, making Scelidosaurus not only one of the earliest complete dinosaurs discovered, but also one of the many that have been found in what, even during its lifetime, was a great range of lands and habitats.

Moving Scelidosaurs

Scelidosaurus is not in any documentaries nor does it have any great influence in cartoons or many other forms of media. It does appear in one game, an educational game known as Dinosaur Safari (see below), but it does not even figure as a main animal there. There are quite a few animals in the game though, so it is good enough that it made the cut. It may look a little shoddy, but it is a bit older, and as such that is actually a pretty good looking game overall and I will not complain.

Scelidosaurus May Confuse Younger Viewers

A reason that younger readers/viewers may get confused is that Scelidosaurus is a basal member of the group and therefore looks a bit like a stegosaur and a bit like an ankylosaur without being either. That said, there is no reason that the children of the world should not get acquainted with KidsDinos and Enchanted Learning. Additionally, they can color online or print out a copy of coloring pages on this site or the image shown below is also available.

Via Arthur's dinosaur clipart

Scelidiosaurs Slide Show

Nobu Tamura's updated Scelidosaurus

Yesterday I posted an image of a Scelidosaurus illustrated by Nobu Tamura and today is another version of Scelidosaurus by the same illustrator. He has changed the posture slightly, shortening the forelimbs a little and making the hindlimb to forelimb angle slightly deeper. With a slightly smaller head and plates of any kind on its back Scelidosaurus would certainly look very much like a typical stegosaur in the updated posture. The tail is lacking any form of spikes, but it does have smaller dermal nodules all along the tail along the top and two stripes down the side as well as a chevron-like ridge on the ventral side of the tail. While not much of a weapon, the tail could be used to deter predators if it had any moment gaining abilities. Its position and the structure of the skeleton do indicate some ability to move the tail with a little bit of speed and power, much like its descendants in both the Stegosauria and Ankylosauria.

Lyme Regis Museum, Dorset, England

The oldest posture models of Scelidosaurus, going back to O.C. Marsh, were much like many other dinosaurs of the past. Tail dragging and a splayed out posture were the expected and the normal postures of dinosaurs, including Scelidosaurus. The neck was stocky and fattened, but the head stayed nearly the same regardless of the model's origin or time space in time. Overall, as with many of the Crystal Palace and other 19th century statues, Scelidosaurus appeared to be an Iguana at the extremely odd end of the Iguana plastic toy spectrum. Notice that the hindlimb structure and the forelimb are slightly splayed and at nearly the exact some shoulder/hip level.

Slide on Over Scelidosaurus

©Nobu Tamura

Armored dinosaurs are always fun to talk about. Lightly armored dinosaurs are sometimes even more interesting as they tend to possess a lot of intermediate and basal characteristics; not that fully armored dinosaurs do not sometimes exhibit such characteristics. The "limb lizard" Scelidosaurus (one species, Scelidosaurus harrisonii) is one such dinosaur from the Jurassic of England. Scelidosaurus is the titular animal of the family Scelidosauridae and is a basal member of the Thyreophora; this means that the family Scelidosauridae is on a lower branch than either the Ankylosauridae and Nodosauridae (collectively Ankylosauria) or the Stegosauridae. Scelidosaurus is one of the most basal and primitive Thyreophorans. At about 13 feet (4m) long it is also a very short and stocky animal, though not stocky enough to be considered "big" in terms of dinosaurs; its estimated weight is given in kilograms rather than tons as with most stocky and well built dinosaurs. The armor on this dinosaur is extremely primitive in terms of later members of its group as well, but it is somewhat protected for an early dinosaur of the Thyreophora. The hindlimbs are longer than the forelimbs also, giving it a very Stegosaur look and possibly the opportunity to rear up to graze above its quadrupedal height while on those longer hindlimbs.

The Saddest Day

Taken from dinosaurjim.com, which was taken from elsewhere. If anyone knows the original illustrator please let me know. It may be based off of Scott Hartman's skeleton, but it is not the one he has posted on his site.

In one of the most miserable turns of popularity for a dinosaur, Torvosaurus was reignited in the public imagination recently when a Torvosaurus nest was announced as having been discovered in Portugal in 2005. The nest and the scientific importance of such a find aside, it was a sad discovery as well. Not only were their crushed eggs in the nest but there were also embryonic/hatchling bones in the mix. The discovery did paint an amazing portrait of the evolutionary position of Torvosaurus as a primitive theropod though. The Torvosaurus eggs were protected by a single layer of shell material whereas other dinosaurs create up double layer shells and birds typically lay eggs with three layers of shell. We have seen, though, that Torvosaurus was somewhat famous prior to this announcement; it did appear in a very key role in an episode of Dinosaur Revolution after all. It also appeared in cartoon form in Dinosaur King (4KidsTV did not post this episode but it is on YouTube anyway in a series of videos). The Dinosaur King card game has a fairly impressive assortment of Torvosaurus cards also. Toys exist as well, of course, as we expect with a well known dinosaur.

Welcome to Wednesday

Nathan Eldon Tanner probably never expected to have a dinosaur named after him. He did, however, and it just happened to be one of the largest predators of the Jurassic that happens to have had material located on two continents. Torvosaurus tanneri is a pretty interesting dinosaur for reasons other than its linked history via its name with the Church of Latter Day Saints. The Portuguese material attributed to Torvosaurus consists of a single tibia; that is some pretty distinctive bone matter to be able to be attributed to a species from another continent based entirely on that sole fragment of an entire living being. Colorado material is slightly more substantial, obviously, given that the animal was described and possesses enough characters to not only definitively differentiate from other North American Jurassic predators but also to warrant a proposal to elevate its status to that of a principal family. Torvosaurus was, as the flora and fauna discovered in and around the area in which Torvosaurus was discovered in Colorado, a predator that lived near rivers, wetlands, and an alkaline lake (Portuguese data of the habitat of Torvosaurus is not known in full at this time). All kinds of animals and plants were discovered in the Dry Mesa Quarry of Montrose County Colorado (along the border of Colorado and Utah). Studies of the channel flow velocity and deposition of bones in the dry Mesa Quarry have been done, but at the moment I do not have the data that shows where within the channel Torvosaurus material was discovered. It appears that predator remains are concentrated in the lower velocity areas of the channel flow, according to the study.

Torvosaurus Gets Inked

©Dmitry Bogdanov

Torvosaurus has been mentioned in a few studies. Obviously the paper naming the dinosaur describes Torvosaurus; that should be understood without having to be said.What does exist additionally, though, is very nice in the way of research and additional materials to learn more about Torvosaurus. The Portuguese find of Torvosaurus is well documented as is its attribution to the genus Torvosaurus; at a page and a half it is also concise and gets quickly and directly to the point of comparing the Portuguese tibia to other dinosaurs discovered in Portugal as well as the Colorado material of Torvosaurus. James Jensen, one of the original authors, further described Torvosaurus and the contemporary fauna in a paper on Uncompaghre dinosaur fauna (Uncompaghre is the 6th tallest peak  in Colorado and the formation refers to plateau area around the peak as well). Jensen's paper on the fauna of the formation is short but concise and, as such, is not heavily detailed but does provide a good overview of Torvosaurus' neighbors and landscape. Additionally, Jensen raises the family Torvosauridae in this paper.

Torvosaurus on the Little Screen

Torvosaurus is one of those dinosaurs that was chosen to appear in the short series Dinosaur Revolution. The reviews on Dinosaur Revolution are mixed, but I feel that an educated mind can see both the fantasy of Hollywood as well as the science and take things with a grain of salt while doing their own research to double check the facts; though I know that the majority of the world does not double check facts of television shows and I am perhaps a little idealistic when it comes to assuming that people watching documentaries further research that which they see on television. As is sometimes done with television, the Torvosaurus and an Allosaurus in the episode are given immensely constructed and complex back stories, somewhat anthropomorphizing the dinosaurs. The Torvosaurus is portrayed as the more evil or bad of the two and sympathy is created for the Allosaurus and, in the way of many documentaries and shows with animals that are characterized in human ways, the "bad guy" ends up being run off or dies; like I stated before, there is a grain of salt approach to watching shows like this. Regardless, there are two relevant clips for today from the episode that show a model of Torvosaurus in action. The first is above and depicts the supposed battle between a Torvosaurus and an Allosaurus. The second is sort of a montage of Torvosaurus hunting sauropods called Dinheirosaurus.

Torvosaurus Educates, Does Not Eat, Children

We know if Torvosaurus were alive today it would not differentiate between adults and children in its diet, but we can assume that today it will only educate children rather than eat them. Doing so are the nice webmasters of Educated Learning in both abbreviated and detailed fact pages, the well written blog of Brian Switek, and a page on Dinosaur Jungle. Additionally, there is a rather fun educational video from HooplaKidz TV, which we have used before here, that depicts an animated Torvosaurus describing herself and just generally being entertaining. In terms of actual coloring pages today, there are none for Torvosaurus; our first missing link, so to speak, of the day. There are quality images that would make good coloring sheets, but they are the property of their artists and are not meant for coloring, so if anyone out there wants to color them in they need to be sure to ask the permission of the artists before using their works.

Key Features of Torvosaurus

The natural conclusion to yesterday's art by Davide Bonadonna

Torvosaurus differs from many other North American and European giants in a number of ways. Obviously the European material from Portugal did not undergo the adaptations witnessed in other European dinosaurs that are the results of insular dwarfism (as so recently discussed both last week and in the discussion of Balar bondoc). In North America the material gathered in Colorado and elsewhere, including potential material from Wyoming and Utah, was slightly smaller than or equal to the largest predators found in the west as contemporaries of Torvosaurus; "savage lizard" sounds a little more fearsome than "different lizard" (Allosaurus) but a little less fearsome than "lizard-eating master" (Saurophaganax) and so is nestled in both size and fantastic nature of name nicely in the middle of its contemporaries. Physically there were also many differences between this megalosaurid and its allosaurid contemporaries preserved in the fossil remains; no good "mummifications" exist for all of these contemporaries to my knowledge that would allow for extensive soft anatomy comparison.

Skeleton at the North American Museum of Ancient Life (Thanksgiving Point, Lehi, UT), photo courtesy of user Ninjatacoshell

The teeth of Torvosaurus are impressive, though not completely definitive of the genus or the family. Some of the skeletal markers that make it different from its contemporaries include the length of its ilia and pubic bones as well as lack of ornamentations on specific areas of the skull such as the lacrimal ridges (a bone of the "face" near the antorbital fenestra and nasal bones). Allosaurus, especially in the past few years, has been depicted with rather prominent nasal, orbital, and lacrimal ridges of bone and soft tissue, particularly the latter. Megalosaurids, such as Torvosaurus, show no evidence of ornamentation along these bones and it is assumed that the lack of ornamentation in the bone was a precursor for a lack of ornamentation of soft tissue in those areas. The skulls of the two dinosaurs are also different in overall size and length with Torvosaurus possessing a longer nasal bone that creates more solid bone area between the nares and antorbital fenstra than is found in the more rounded off and shortened muzzle of Allosaurus. Fore and hindlimbs of Torvosaurus are somewhat like those of Allosaurus; both have three clawed hands as well as feet. The claws of Torvosaurus appear slightly larger and stronger, but I have not seen a documented study to support this at the current time.

From Colorado to Portugal

©Davide Bonadonna

First and foremost, many thanks to my sister Anna for taking over last week while I was in the field helping a colleague trap mice and avoid rattlesnakes. If you did not notice a difference, that means she did a fantastic job, right? Kudos to the author and artist to be!

This week I have a monster of a dinosaur for us. Obviously, in sticking with my typical rotation, we are going to look at a predator this week, and not just any predator, but one that has been discovered in both Colorado and Portugal in varying stages of life including as an egg and is a fearsome predator of the late Jurassic. Larger than most of its contemporaries, including most Allosaurus individuals, Torvosaurus tanneri was a forced to be reckoned with. Three clawed hands and massive jaws were supported by a robust torso and well muscled and strong legs in this megalosaur. This "savage lizard" was between 30 and 26ft (9 and 11m) long and probably weighed nearly 2.2 tons (2 metric tons). The Portuguese specimen is the largest discovered meaning that the eastern counterparts of the Colorado specimens were either slightly larger overall or that the Colorado specimen may be a younger individual than the Portugal specimen. The Portuguese Torvosaurus rivals T. rex's skull and is much larger than any other Jurassic age predator while the Colorado material is slightly smaller than Allosaurus/Saurophaganax and another animal known as Edmarka (which may be synonymous with Torvosaurus).

What A Strange Little Dinosaur

Zalmoxes lacks a lot of popular culture references we have seen on the internet. It did feature in some news stories back when it was renamed and a little afterwards. Zalmoxes has warranted enough looks that it has been detailed by the Natural Museum of History in London on a fact page also. However, as we have seen, it did not manage to ascend to documentary dinosaur status as yet and has also not been portrayed as a model or toy dinosaur to my knowledge at this date. Zalmoxes has made its name in World of Warcraft as an item, as have many other dinosaurs. Apparently it is represented by a robe that players can acquire on a once previously mentioned landscape within the game. Sadly, that is where that popularity ends for Zalmoxes. A greater number of dwarfed dinosaurs from Transylvania are being discovered these days and that will pique interest in someone soon enough I am sure to warrant the creation of a documentary or toys or something else that gets the name out there more.

The Island Life

Brian Cooley's Zalmoxes sculpture

Depending on the specific species, the size of the Zalmoxes differs greatly. Z. shqiperorum was the largest species and could grow up to four and a half meters long. However, the smallest, Z. robustus, would only grow up to three meters long. Z. robustus was thought to be so much smaller than the Z. shqiperorum because of insular dwarfism. Insular dwarfism was the theory that large animals evolved by decreasing in size when the food sources are limited due to lack of land mass. Since Zalmoxes lived on islands, they were said to evolve over generations by decreasing in size so they would not need to eat as much plant matter. This allowed for Zalmoxes to continue to populate and also have lots of available food.

Papers of the Zalmoxes

Zalmoxes, the poor unfortunate "unusual Euornithopod" has had some osteological and phylogenetic study done on it. That 2003 study by Weishampel, Jianu, Csiki, and Norman was the landmark paper that renamed Rhabdodon robustus as Zalmoxes robustus and identified a second species as Zalmoxes shqiperorum. Thankfully Dr. Weishampel is nice enough to host his own papers so we can read the entire paper, all 59 pages, of the in depth anatomical description of Zalmoxes and how it differs, and is thus officially distanced, from Rhabdodon. The matrices and characters are included, which is always nice to have, so that the systematists amongst us can really look at the characters that were analyzed. The osteology of newer specimens has also been discussed, this time only for Z. shqiperorum though. The 2009 paper discusses a new fossil site in Transylvania, Romania and the specimens of Z. shqiperorum that had been unearthed from that location.

No One in Motion

Zalmoxes does not appear in motion pictures, short or full length, animated or computer graphics. There is an alphabet video that mentions Zalmoxes in the Z slot of the alphabet; there really are not too many dinosaur choices in the Z slots of the alphabet. Dinosaur Train's A to Z episode does not use Zalmoxes, sadly for us; I know everyone wants to see the Dinosaur Train song again and again. Zalmoxes, and the other Transylvanian island dinosaurs that have been discovered, truly do deserve their own documentary. Some day this will certainly happen. It has not so far and thus I have nothing to share in terms of video today, unfortunately.

Children and Dwarf Dinosaurs

Science for Kids has a pretty good fact page going for Zalmoxes. It is a bit short, but it gets the important information out there quick and in an easily readable way. Additionally, I found a pretty sweet puzzle site that is any age friendly. You can make the pieces any size you want from a 12x12 puzzle down to a 2x2 puzzle. That means you, or your child/nephew/niece/sibling, can customize the puzzle to fit yours, or their, skill abilities. Pretty nifty if you ask me. Seeing as how you can create your own puzzles on that site, be prepared for more Sunday kid friendly posts with dinosaur puzzles! This will help a lot for dinosaurs that are not as popular. Also, when you are done with your puzzles and reading your facts, here are a couple of coloring pages worth all kinds of time and fun to color and detail!

Rakes for Hands, Giant Heads

Cast in Brussels, photo by Ghedo

Some inconceivable reason caused the curators of the Museum of Natural History in Brussels to take a rather nice cast of the rhabdodontid dinosaur Zalmoxes and give it rakes for hands and feet. A great deal of the skeleton of this genus, spread over two Romanian species and, potentially, a third Austrian species, is well known, but this does not include fore and hind feet. Despite this, enough is known of the rhabdodontid iguanodonts that a reasonably educated guess could have been easily made for the casting of this skeleton. Regardless, we can get a sense of the overall dimensions and lay out of the skeleton of these species by looking at this cast. The scapulae are rather slender and long, which is pretty interesting and the skull is a triangle of sturdy thick bones with a fairly nice dental battery found inside the mouth. The skull truly sets Zalmoxes apart from many other dinosaurs and as such, we will definitely be looking at that in a moment.

Attributed to Anky-Man

The skull, if not the skeleton, of Zalmoxes, is quite robust. Muscles would have create a fairly good bite force, but in all likelihood the main manner of getting energy out of its food would have been through a lot of grinding of the dental battery. The mouth, and it is always up in the air when discussing this, may have been enclosed in a flap of cheek to help in chewing plant matter. A cheek is instrumental in holding vegetation in the mouth during mastication; without a cheek your food would mostly end up falling out onto your favorite t-shirt unless you held it in there with your hands. The skull of Zalmoxes is very iguanodontid in overall shape and form, but it is small and, given the size, more robust than seems necessary for this dinosaur. Perhaps, if insular dwarfism is responsible for the small stature of this dinosaur, the head was the last part of the body to begin to "shrink" through successive adaptations. However, maybe there was a significant bonus to possessing a large tough cranium in Zalmoxes environment.

©Vlad Codrea (via MSNBC)

Those big heads must have been used for something, right? Then again, they could have been mistakes or slow to adapt to the island life. Zalmoxes is thought to have "suffered" from something called progenesis. The main thing to understand about progenesis is that it is a developmental acceleration of life. A rhabdodont that took five years to achieve maturity and then lived another 30 years or so may have been perfectly normal but the same animal, under the effects of progenesis, may have matured in a year or less and only lived between five and 10 years total. Progenesis is not a disease so much as it is an adaptive reaction to an external stimulus that, over generations, forces animals to breed faster in order to sustain population and pass on genetic information. Insular lives may have caused just such a thing to occur and the adaptations of dwarfism as well as progenesis together may well have been enough to cause those sturdy crania of Zalmoxes to stand out as much as they do if they did not do so on account of a beneficial adaptation for large crania. Perhaps we will have a definitive answer to this query soon.

Dinosaurs that Start with the Letter Z

©Mariana Ruiz Villareal

Two species of dinosaur, one originally in the genus Mochlodon, belong in a Z genus. Those dinosaurs are Zalmoxes robustus and Zalmoxes shqiperorum (do not ask me how to pronounce that please). The generic name comes from the Dacian city of Zalmoxis. For my human history deficient friends, Dacia was a region in the Carpathian mountains, now part of quite a few countries including Romania and the Ukraine, between the Tisa and Danube rivers inhabited by a people called the Dacians by the Romans who practiced a religion called Zamolxism, which got its name from Zalmoxis the chief god of the religion who had a city named after him. Essentially, then, the name Zalmoxes, is a tribute to a Dacian city and god. The specific epithets, Z. robustus and Z. shqiperorum, carry the meanings "robust" as in the robust build of the skeleton and the Albanian word for Albania (Shqiperia) respectively. The dinosaurs we are looking at are small, squat rhabdodontid iguanodonts; they were somewhere between a buff looking hypsilophodont with a thick powerful jaw and a basal iguanodont. The two species have different adult sizes with Z. robustus measuring in at about 7 to 10ft (2 to 3m) and Z. shqiperorum at 13 to 15ft (4 to 4.5m). The size was of Z. robustus was attributed to the wonderful spectacle of insular dwarfism, which we have discussed previously in this blog.