Bones and A Brain

Approximately 500 individual bones have been assigned to Ampelosaurus atacis from the excavation sites in Southern France. The femora from that location number approximately 27 individual specimens. These bones are not assumed to have come from singular individuals specifically, meaning that any number from 14 to 27 individuals may be represented by these femora. More interesting, however, is a non-specifically assigned braincase described in 2013 by Knoll, et al. The braincase includes the majority of the skull surrounding the braincase (this includes paired frontals, parietals with extensions, basioccipital, occipital, basisphenoid, parabasisphenoid, prootic, and laterosphenoid). The CT scans and 3D renderings from the description and research are available free on PLOS. The images from the study are wonderfully detailed and freely available, however, they are too large to upload. In order to look at them and appreciate them the link is contained in the reference below.

Knoll F, Ridgely RC, Ortega F, Sanz JL, Witmer LM (2013) Neurocranial Osteology and Neuroanatomy of a Late Cretaceous Titanosaurian Sauropod from Spain (Ampelosaurus sp.). PLoS ONE 8(1): e54991. doi:10.1371/journal.pone.0054991

Originals and Osteologicals

Le Loeuff's original description of the titanosaurid Ampelosaurus is available online as a PDF from the translators over at the Polyglot Paleontologist. The translation is well done and the paper is short but informative. Lacking from this version though are the figure plates and details to which Le Loeuff refers in the paper. The images are available online in other places, including the Academia page of the article uploaded by Le Loeuff. The osteology of the dinosaur has also been discussed in the book Thunder-lizards: The Sauropodomorph Dinosaurs. Some of the discussion for the topic is missing, but if the entire book is available it is worth borrowing and reading the entire section. If not, making do with the missing pages is not the end of the world either.

Video Reviews

Today I thought that we could try something a little different. There is not a documentary or news story or any other such video as we prefer to find on Mondays, however, there are a pair of reviews of the same Ampelosaurus model that we can view. One of the reviewers promises a discussion of the life history of the animal while the other only promises a review of the model. Either way a history of the animal must be discussed to review the authenticity of the model. I shall leave it to the videos to do the rest of the explaining for themselves though.

Tiny Titanosaurs for Tots

The sites that discuss Ampelosaurus are ample (pun intended). About sticks out first because it comes about alphabetically first and because it does, as usual, a very good job of summarizing the key facts and has been written up into an easy to read paragraph also. The NMH of London also has a site dedicated to the dinosaur, but puts out a lesser fount of information than the About page. This is okay to a point because they do make it up a little with a nice quality original illustration. It is not the same of course, as having quality information. KidsDinos and Prehistoric Wildlife both have respectable fact files and nice illustrations of the dinosaur. The search can continue beyond those sites, but the quality of the sites falls off quite a bit. There is no quality coloring page available today either, but these sites should keep young readers busy for a while and the illustrations can easily be used as references to draw their own dinosaurs today!

Protection and Little Titanosaurs

Compilation uncredited, dinosaur illustration is the same as yesterday (Dmitry Bogdanov).

Ampelosaurus, despite being a titanosaurid, appears to have been a somewhat smaller sauropod than is often thought of when we hear the name "titanosaur." This small-ish appearance of Ampelosaurus could be an artifact of the size of the femora discovered, but considering the number and diverse amount of remains that have been discovered, this most likely simply was a smaller titanosaur. This idea is probably best exemplified in illustrations (other than in the size comparison graphic above) by Alain Beneteau's depiction of a Taracosaurus attacking an Ampelosaurus. The head of the sauropod is, in all the illustrations that I have seen, are nearly identical. There is a known braincase and partial skull that accounts for the similarity in this aspect of all the illustrations. The back of Ampelosaurus is covered in osteoderms that have also been unearthed. As far as I know there is only a single photographed osteoderm available on the internet for our viewing.

Femora of France

©Dmitry Bogdanov

Discovered in France and Spain, Ampelosaurus atacis Le Loeuffe 1995 (Vine lizard of the Aude River) was a Cretaceous titanosaurid that presumably lived throughout Europe (though this has not been substantiated as yet). Many partial sets of remains of this dinosaur have been recovered, but the majority of those remains are actually represented by a single bone of the skeleton; the femur. The catalog of animals found near this dinosaur actually outweighs its gargantuan remains, but we can discuss that at a later time this week. Though known as a French dinosaur originally, some of the most interesting remains, including a braincase, have been discovered in Spain.

Human Ankle, Tarsier Leg

The morphology of Archicebus indicates that it is one of, if not exactly the last common ancestor of all primates from humans to monkeys. The largest similarities between primates and Archicebus are found in the metatarsals and the ankle, particularly the calcaneus. These bones are similar in shape and proportion to those seen in later primates. Archicebus, however, also possesses a skull, teeth, and limb bones that are much more common to a group of lower mammals (tarsiers).

Paper Time

The find of Archicebus has been important and monumental. The papers, many of the illustrations of which we have seen here this week, that have been published are few in number but are pretty informative and useful. The original paper and a completely independent paper that can probably be read in full with institutional access (I do not have that at home). Either way, the original paper is worth reading and it is the kind of paper that I never want to spoil by summarizing here. The discussion of haplorhine evolution is short, considering the overall paper length, but is definitely helpful in knowing where these tiny little primates rest on the tree of life.

News and Movies

To start, there is good news in the world. You can find that news here. It is very nice to be a part of the group and it is going to be quite a busy and fun time in the lab now.

In terms of video, there is a surprising lack of news stories associated with the relatively newly announced animal. The video shown here is a small snippet of that news. A slightly better news story can still be found on the NTD (New Tang Dynasty) television service website (the site states they are based in New York and broadcasts directly to mainland China and worldwide). This news story at least shows a portion of an interview with Ni Xijun that I saw the other day. Unfortunately, that interview was not in English at all. The NTD story translates it for us though thankfully.

Short Listed

Today there is not much out there. The newest finds usually have the fewest links and Archicebus is not that much different from any other fossil animal. There is a short round up on the About (http://dinosaurs.about.com/od/mesozoicmammals/p/Archicebus.htm) pages, which have always been pretty extensive in their coverage of the animal kingdom. Unfortunately, today is one of those rare days where we do not have a lot of specialized articles for people to let their kids loose on the internet to read. In that vein, however, it may be worth the time to go about searching safely and discuss what makes websites acceptable sources of information. There's a cheat sheet for that in case it is a topic that has never been discussed in your house (http://bit.ly/1CiN8tr).

Creepy Smiles

© Xijun Ni

The creepy smile of Archicebus achilles in this restoration is a little odd, though if I grabbed an insect that size for dinner as a rather small primate I would be just as happy as Archicebus appears to be. The rather large toes of the hindlimb in the reconstruction are true to those of the fossil remains as well. The nearly opposable thumbs on the forelimb are obviously useful for grasping insects like this rather large piece of dinner. The only thing that has not been alluded to with the fossil used as a model for the illustration is the potential ability of the tail to be used in a prehensile manner. The illustration does appear rather tarsier-like, which is a good thing as the animal is hypothesized to have been a member of the tree living between tarsier and monkey families.

That Prehensile Tail

© Xijun Ni

The first primates are probably what the populace thinks of when one says something like "prominent early mammals". Therefore, as the last of the strictly mammal weeks here, I present to allthe earliest recognized primate, Archicebus achilles Ni et al 2013. This little tree-scrambling primate is considered the first "haplorhine" or dry-nosed primate, a group that monkeys, apes, and humans all belong to as well. Its discovery in Asia supports hypotheses that primates first began to evolve in Asia and later migrated toward and eventually into Africa, where it is known that humans later evolved and originally migrated from. The name of the animal originated from the Greek and Latin combination meaning "Beginning monkey" with a reference to Achilles, supposedly due to a significantly novel calcaneus discovered in the fossil. The animal is comparable in weight to the smallest extant primates (Mouse Lemurs) but is thought to have been active during the day rather than nocturnally, like most small mammals were, and still largely are, when this little creature first began to confidently stride around on the planet.

Cartoon Popularity

Cimolestes and other small mammals do not make it into the toy market very often, which is quite okay. They often do not make much of a mark in the video game market either. Cimolestes does, however, actually hit a good chunk of the popular arena marketed toward kids thanks to Dinosaur Train that includes both video games, even if it is still just a small portion of the games online that are devoted directly to the Dinosaur Train genre. The same goes for toys; Cimolestes only really appears where Dinosaur Train characters are concerned. These are both hard to find online either way though. It actually seems that the only way that Cimolestes has been introduced to the public over the years is through technical literature (popularized books are absent) and the Dinosaur Train series.

What About Your Tail?

I noticed that there was a pretty fantastic piece of art out there but it has no illustrator credit and no dollar amount attached to it. Therefore, I present it to you today as a link to the bureau that apparently manages its release. I do not think that breaks any kind of copyright rules, so it should be okay. The image does not really address what I wanted to address today, but it is pretty fantastic looking. The thing I really wanted to look at today is the tail of Cimolestes. Most small rodents (e.g. anything smaller than Capybara and Beaver) we think of either have wiry little tails and use them as balancing tools or big bushy tails that can be used as balancing tools or to help provide warmth. Cimolestes is usually depicted with the wiry looking tail that we see in mice, rats, and shrews. It stands to reason, and considering the environment at the time, that there was not much need for Cimolestes to have a bushy tail for warming itself if this wiry tail counterbalance is correct. Balancing as it scrambled up and down the tree was probably the limit of what Cimolestes needed its tail for anyway considering that it used all four limbs to scramble around the tree. Any small help in balancing while running was a benefit for an animal scrambling away from dinosaur that could swallow it whole if it tripped or otherwise lost its balance when it was running away. Long tails in extant mammals sometimes serve the exact same purpose. Think about how well adapted Cimolestes was the next time you see a rat, mouse, or even a cat running along a fence top!

Not Necessarily Correct

©Carl Buell

The image presented here is from a news story about a small mammal that mentions Cimolestes and discusses their habitat. The story does not mention whether or not this image of Cimolestes or the other small mammal that is being discussed, so we can use this image today to go with the other papers and articles that I found about Cimolestes that are pretty interesting. The first article that was really good today actually discussed Cimolestes in a round about way as it actually centered on the evolution of placental mammals rather than the mammal itself. Woodward's 1910 description of a mandible found in Montana is also a good addition to the reading list for today. It notes how small details can be used to attribute something as small as a mandible to a known species. The final paper worth reading for the day is about two new potential specimens from the Gobi Desert. The specimens do not belong to the genus Cimolestes, but that animal is described and discussed in comparisons to the two genera that are being described in the paper. This kind of cross identification and description are important to be aware of and to be able to understand when reading future papers (consider it a future preparation tool for you younger scientists)

Hopping and Jumping

Aside from the episode of Dinosaur Train with Cimolestes there are not an awful lot (read: zero/none) of animated or puppeted references to Cimolestes in video, cartoon, or documentary of any kind. There is a nifty little animation that uses the scientific interpretations of the purported movements of the animal. It is a tiny little series of animations of Cimolestes hopping about, which is pretty cool looking honestly. The model is a little more mouse like than I think it should, in my most humble opinion of never having studied this animal in depth at all.

Two Sites Today

There are only two sites needed today. One is About, because it has a nice list of facts and a short paragraph which means it caters to a universal group of readers. The other is the PBS page for Dinosaur Train. The reason this stands alone with the fact page as an assist is because we get a fair number of facts from Dr. Scott Sampson and some inferred behavior discussion. Watching the episode with Cimolestes is also helpful, but there is not a link here for that today; check the PBS site and Netflix for the episode.

Perception of A Tree Rat

©Steve White

Cimolestes was a tree climbing rat sized mammal and it has been drawn as such many times. It has also been drawn to look something like a shrew and even an opossum. Regardless, it is a small mammal with a rodent-like body plan. Adept at clambering up trees and chasing down insects, Cimolestes was an iconic mammal of the Mesozoic. The iconic image of a very small mammal racing around underfoot of dinosaurs is perfectly filled by Cimolestes, however it is usually drawn in the trees, like this image. Its agile little body was slender, but the fluffy images that make it look more like an opossum (not this one) could be said to just be the result of its fur being puffed up. This less furry version looks a little sly, but may be a little more accurate.

Thievery of Bugs

Basal non-placental eutherians are a weird off-shoot of the extant group of eutherians, which are typically known to be placental mammals. One of the best known of those mammals was the Cretaceous scamperer Cimolestes. A North American fossil mammal of the trees the size of a rat, Cimolestes is thought to have chased insects around the arboreal habitats it called home and, probably often, temporary forays into the undergrowth below. Either way, Cimolestes may have been in a transitional place in the fossil history of mammals between marsupials and placental mammals. Additionally, look at how fuzzy and mammaly this animal has finally gotten to be. About time that mammals have started to look like mammals in this jumpy history we have been following lately!

Popularly Not Named

The name of Thrinaxodon is not used in the documentary for which it was used as a model. It appears all over the place though under its own name. Thrinaxodon is included in many other media, including illustrations and toys. The animal appears in popular card games and in the set of collector's cards shown below.

In 1982 South Africa put Thrinaxodon on a stamp also. In a more realistic vein, UT Austin's Digimorph collection is supplemented with a Thrinaxodon skull. My favorite popular culture mention of Thrinaxodon, however, comes from Wizards of the Coast's long standing collectible card game Magic: The Gathering.

Needing Citations

This image desperately needs a citation. Aside from needing a proper credit, it is a great image and very succinctly sums up a lot of the known anatomy of Thrinaxodon. The author/illustrator even included the secondary palate, though it is not visible, which is arguably the most important feature of the entire skeleton in terms of being nearly mammalian. There are other characteristics that show its nearness to the animals that would eventually become fully accredited, card carrying mammals such as the paired occipital condyles, modified jaws with teeth geared toward chewing and the loss of the pineal foramen. There has been speculation that the thorax and abdomen of this animal were separated by a primitive but effective mammalian diaphragm also, which is nearly as significant as the prediction that these animals or their nearest descendants may have been producing milk from mammary glands, a very mammalian trait.

They Wrote A Book

Seriously, they wrote a book on Thrinaxodon. The book is actually only on the cranial anatomy of the small near-mammal, which is slightly more impressive, if that was possible. The book is available as a plain html site from UCMP. That site, in turn, links an even larger work from the University of Texas that was written by Rowe, Carlson, and Bottorff in 1993. I feel like that level of information may be enough for most readers for a day, but there are also published studies on growth patterns and tooth growth and replacement. The writings explain themselves today and are on three of the most interesting topics around Thrinaxodon, which means they require very little further discussion. Enjoy your reading today ladies and gentlemen, there is quite a lot available to you!

Turning to Other Sources

As we have done many times, we have to go to a similar but different species to see anything like what the animal we are discussing in a documentary. Thankfully, the small near-reptile category of lifestyle was well represented despite being an animal other than Thrinaxodon. Labeled simply as "cynodont" in the species list of Walking With Dinosaurs Episode 1, the inspiration for the near-mammal was actually Thrinaxodon though it was not called that in the show. Knowing that, perhaps it is a little bit of misinformation to say that there is not a documentary that has Thrinaxodon in it. The animal is not entirely factual to Thrinaxodon alone however, and incorporates other near-mammals as well. Either way, watching it is beneficial.

Hear and See the Near-Mammal

The fact pages abound for Thrinaxodon. Part of the popularity is in its inherent "cute factor" and the other part lies in its nearness to mammals. Whatever makes it popular, it allows us more of a platform to educate that critical next generation in yet another fossil animal! As noted, there are many sites to look at, including About and the Walking With Wikis which both present the information in a manner that is more accessible for all ages and reading levels. The site Prehistoric Wildlife presents the information as an essay, making it a little less attainable to lower level readers. A video produced by Menteon Learning also lays out this information for us, though does not go into too much depth. This is actually not a bad thing though, as it allows the video to appear concise and accurate in its information, though more information is available than is presented. I am both happy and sad to say that I have another Josep Zacarias link that could certainly be used as a coloring book image as well today. Happy for obvious reasons, but sad because I also found it online without proper attribution, and Mr. Zacarias is a hardworking artist and deserves credit for his work!

Streamlined Digger

Thrinaxodon was built for digging and hiding. The small near-mammal was thin and cylindrical (as far as any tetrapod can be cylindrical anyway) and had a head that was elongated rostrocaudally. This gave it a long skinny body overall and made it look somewhat weasel-like. The major exception to this was the large, but slender, canine-like face with its large canine teeth that appear almost like tusks. The large teeth were not helpful for digging in any specific way, however, the limbs were most built for burrowing. They were short and powerful for digging and burrowing out their homes, but still elongated enough to be suitable for propelling it through the underbrush of small ferns and cycads that populated its world. Given its ability to scurry, probable nocturnal nature, and large teeth, Thrinaxodon was at least omnivorous and most likely fed on insects, lizards, and possibly other near-mammals/mammals and dinosaur nestlings or eggs. Burrowing was an effective way for an animal like this to hide during the day while it ran around at night getting into those dinosaur nests, other near-mammal burrows, and catching nocturnal insets. Efficient as it was then, burrowing is still extremely efficient and useful for small mammals, such as mice and mink, and larger mammals like badgers and otters (River Otters get rather large). It is no wonder that animals like Thrinaxodon would have used burrows for protection. Imagine this small animal shimmying through the hardened soil tunnels!

Breathing and Chewing

Few people stop and marvel at the wonder of being able to chew and breathe at the same time. The ability to breathe while holding food or water in the mouth has evolved a few times in the history of life and each time it has been a remarkable innovation in the line of animals in which it evolved. One of the earliest transitional near-mammals that has been found with the ability to breathe and chew was the Cynodontid Thrinaxodon. Thrinaxodon possessed a primitive secondary palate making this possible. A single species is recognized in the genus: Thrinaxodon liorhinus. This small near-mammal also possessed two small tusk-like teeth and is thought to have lived in riverbank burrows. At under 0.61 meters (2 feet) in length, this small animal would run and hide, use its long whiskers, and come out after dark under the feet of the earliest dinosaurs. These little animals were furry and weasel-like, but they were definitely wonderfully interesting little animals.

©Nobu Tamura

Mighty Moschops

Moschops is a well known unknown beast. That is very confusing, I know. When I have to say that about an animal, what I mean is that no one knows the name of the animal but they have seen the image, somewhere, it happens quite often with prehistoric animals. Moschops has appeared in many popular culture venues, as we have seen. It even featured as a main character in a children's program; that program was a little inaccurate of course. The line drawings of Trainor were even less accurate, overall, though he attempted to keep some of the science accurate. Some old toys still exist, though not many new molds of Moschops have been utilized lately. One of those few new molds has made its way onto YouTube, as toys often do, as a review. Big Time Attic made day #84 in their Dino-A-Day list an entry about Moschops. Their illustration is well done, but kept cartoony, like the Cannons typically tend to do with their artwork (I personally enjoy the child-like aspect of their art).

Calf Face of the Cape

There are four recognized species, though two are considered recognized but doubtful, of Moschops. The heavily ossified skull of Moschops is a defining feature of the animal that may, some speculate, may have been thickly built from birth onward. The speculation states that the fat but short tail adequately counter-balanced the heavy skull of Moschops and that it would have existed with the animal from birth if the head started out heavily ossified. Contrary-wise, if the skull became ossified over time as the animal aged, the counter-balancing tail could have started out miniscule and grown in coordination with the large skull. The skull, in true heavy helmeted-head fashion in the natural world, is very akinetic and appears to lack many visible sutures over much of its surface. The cemented nature of a skull that lacks sutures and kinesis allows for us to infer many behaviors, or at least make some interesting educated guesses, from looking at similar extant taxa with highly "helmeted" akinetic heads (e.g. Bighorn Sheep, American Bison). Due to this, there have been behaviors such as head-butting and display motions inferred in Moschops. The individual pits and bumps on the skull probably aided in the display function of the thick helmeted head of Moschops more than they would have in the physical combat part of intra- or interspecies combat.

Discussing Moschops

In 1936 Frank Byrne of Kansas State University named and described Moschoides which turned out to be a junior synonym of Moschops. It is funny in that Byrne specifically mentions in the first paragraph the large similarity between his new specimen and Moschops. Shortly thereafter, in 1940, Byrne published another article contemplating the evolution of mammal-like reptiles from the Karoo. In that article he again mentioned the similarities between Moschoides and Moschops without tying the two genera together. His discussion of the evolution of the animals is interesting though, despite this discrepancy. On a totally unrelated note, the fighting abilities, which I pondered for a moment or two on either Friday or Saturday, was actually studied and published in 1975 in the first volume of Paleobiology. Herbert Barghusen in Chicago is responsible for reviewing the fighting adaptations of all dinocephalians.

Jim Trainor, Not A Documentarian

Jim Trainor's short film The Moschops is the only short film in his fake "Highlights of the Permian Era" series. The science that exists in it is not the worst science out there, believe it or not, but it is certainly not entirely accurate by any means. The line drawings are typical Jim Trainor (to many that means they are awful). Usually on Mondays I try to only show quality documentaries and resort to not great documentaries where needed. This short film falls into the mostly entertainment category, so attempt to restrain the angry "That's not a documentary or exceptionally educational" comments if you can. The second part of the film, not linked here, gets a little more wayward (i.e. less G rated) with its treatment of the subject matter, hence my reluctance to share the link for that. The problem with a lot of these early mammal-like relatives of modern mammals is that there is not a lot of quality documentary clippings out there. The Walking With Series turns out to be, again, one of the more reliable nearly accurate shows, but it does not exactly discuss the animals we are interested in here today. The non-related Scutosaurus from the series Walking With Monsters probably best shows the posture and a similar gait while Edaphosaurus is probably most similar in diet. Unfortunately, of course, neither is Moschops.