STL Science Center

STL Science Center

30 June 2017

Fantasy and Dinosaurs

©Elise B (Elisetrations)
As we all know, fantastic representations of dinosaurs are often not scientifically accurate or exaggerate some of the most interesting details of the dinosaurs that best accent the points of the fantastic representation of the dinosaur that the illustrator wants to convey. In this illustration,  the fantasy is that of a lovable pet dinosaur, or companion dinosaur may be a better term, for a happy little girl in a pastel yellow dress. The real estimated size of Chaoyangsaurus is actually fairly well represented by this interpretation of the dinosaur, though it could be said to be a small exaggeration of this estimation. This is, of course, assuming that this little girl is approximately 5 or 6 years old and of average size for a young lady of this age. Regardless, the hypothetical quill knobs seen in the earlier posted Tamura illustration are repeated here along the dorsal aspect of the most rostral tail and the head of the animal is slightly more generically fashioned as an ornithischian head than as a ceratopsian line dinosaur; this is possibly more appropriate for the animal however. The image is striking in its simplistic lines and colors, though, and the fantasy of a dinosaur and young girl sitting by a stream is somewhat intriguing.

29 June 2017

Making It Famous

Sometimes dinosaurs with very little material seem to be much more hyped than they deserve, but when the animal is as important to the evolutionary history of its line as Chaoyangsaurus is it is not much of a stretch of the imagination that the dinosaur deserves to be popularized in both the media and the professional paleontological community. The importance of the low-yield of material attributed to Chaoyangsaurus is not only in showing that our world hosted many different sizes of dinosaurs, but also in what is arguably the more relevant capacity of showing another link in the family history of ceratopsian dinosaurs and effectively enhancing our knowledge of their similarities and differences with their nearest cousins. This includes dinosaurs like Pachycephalosaurus. Though Chaoyangsaurus is a very distant relative, it certainly helps us fill in gaps in our knowledge. To that end, we have seen many attempts to understand the familial ties and to describe Chaoyangsaurus throughout this week that are impressive and have reached well into the professional, amateur, and general public arenas. There have not been cartoons or feature length movies, these arguably help the most to interest the general public, but there have been news stories and books like New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. This book is a very technical tome of scientific presentations, but as a member of the general public, then an amateur, and now an in training member of the professional field, I can say that books like this generate a lot of interest in certain people around the world. Never underestimate someone that is keenly aware of what they want to learn and their ability to learn it in formal and informal settings; dinosaurs like Chaoyangsaurus that are less visible to the public than Tyrannosaurus but still are well known names with children (and it is, strangely and almost frighteningly) prove this mindset.

28 June 2017

The Face of Chaoyangsaurus

©Jamie A Headden
Creative Commons Attribution 3.0 Unported
The type material of Chaoyangsaurus consists mainly of dorsal cranial material including the mandible. There are are also some shoulder girdle materials and cervical vertebrae. The skull elements, particularly the maxilla and the mandible, contain the characteristics that associate the small dinosaur with its descendants, the ceratopsians. The teeth possessed similar wear patterns to those seen in definitive early ceratopsians and psittacosaurs like Psittacosaurus. The snout of Chaoyangsaurus and its jugals are also similar to those in ceratopsians. The jugal bones are a set of bones in the "cheek" of ceratopsian dinosaurs that give the larger dinosaurs their characteristically pointy jowls. Phylogenetic analyses taking these and many other characteristics into consideration in the original paper placed Chaoyangsaurus into a polytomy with Psittacosaurus and the base of the ceratopsian family tree proper.

27 June 2017

Chaoyangsaurus and the Ceratopsians

Chaoyangsaurus was initially described in 1999 by Zhao, Cheng, and Xu in the Journal of Vertebrate Paleontology as an early ceratopsian from Liaoning, China. Their description included detailed maps of the region from where the fossils were recovered as well as detailed photographs of the type materials. Many of the remaining papers that reference the animal are more about the origins of ceratopsians and characteristics of the family that started showing up in animals like Chaoyangsaurus. These studies that mention the dinosaur include Xijin, et al.'s Houcheng Formation ceratopsian as well as Xu, et al.'s description of early ceratopsians and discussion about Liaoceratops. These discussions of the evolution of ceratopsians occur frequently in research and often discuss animals like Chaoyangsaurus, though not always of course, because the evolutionary history of ceratopsians is complicated and loaded with taxa.

25 June 2017

Tiny Facts

Chaoyangsaurus is one of the smaller dinosaurs we have discussed here and it has smaller facts and yet the same amount of fact pages as many of its larger ancestors, descendants, and contemporaries. These pages vary considerably but the information is generally similar or at least presented in ways that are appropriate for their target audiences. The most simplistic of these pages, as it always is, because the Natural History Museum of London wants to convey information as quickly and as easily as possible. Their page on Chaoyangsaurus is supposed to have a nice simplified line drawing of the dinosaur, but it is not loading for me today. Hopefully this simplified version of the dinosaur will load for other people. Prehistoric Wildlife, meanwhile, does not have any illustrations, but does augment the listed information with a very short written description of the animal. The Dinosaur Database takes both approaches and makes a single page with short written descriptions (shorter than Prehistoric Wildlife) and two different interpretations of Chaoyangsaurus. The two interpretations show the dinosaur as a typical, old school, taut skin reptile and the second version is actually the image shared yesterday. Despite this shorter interpretation of the facts, the pages all together paint a fairly complete picture of the dinosaur.

24 June 2017

Before Horned Dinosaurs Got Ugly

Ceratopsians are interesting in their own right and some might even say that they look rather interesting. Prior to the evolutionary shift that leads to ceratopsians proper, a small ornithischian ancestor with a skull that shows some characteristics of basal ceratopsians without fitting into that family due to other, more differential, characters, was running about in the undergrowth and under the feet of giants. Chaoyangsaurus youngi Zhao, Cheng, and Xu, 1999 was named for the Chaoyang area and specifically after the Chinese paleontologist C. C. Young (Yang Zhongjian). Measuring in at approximately 1.1m (a little over 3ft), Chaoyangsaurus inhabited the Late Jurassic of China and is often depicted as a bipedal herbivore with (hypothetical) quills along the tail and caudal portion of the back. The speculative nature of this illustration is one of the first things that the artist acknowledges about the work but it also poses some interesting questions for us this week.
©Nobu Tamura

23 June 2017

Illustrated or Not

As usual this week, this entry is a little shorter than our typical entries for any given subject. As interesting as illustrations about Triassic subjects can be, especially considering the majority of these animals that are illustrated are early dinosaurs. Dinosaurs that do not look much like what people expect dinosaurs to be are intriguing and sometimes confusing to many people; this is a conversation I have had many times over with random people. One of the more interesting illustrations that does exist of Efraasia is slightly older and depicts Efraasia walking almost quadrupedally, but with its hindlimbs in a position that suggests bipedal locomotion. This illustration, like all the other illustrations of Efraasia simply depicts the animal as is by itself and without any kind of background. This version of the sauropodomorph is simple, but does have odd fingers, and is somewhat salamander like in its general appearance.

22 June 2017

Size of the Dinosaur

Efraasia was originally considered to be a small animal, based on fragmentary remains that could not be assembled extremely well, but it was later realized that the animal was much larger than believed. The estimated larger size is approximately 6.5m (21 ft). The dinosaur was still small for its size, but by small we mean gracile and lightly built rather than short or thin. The gracile hands and feet of the animal could be used to imply facultative quadrupedalism, though this is also implied by the fact that may other very early sauropodomorphs were known to be capable of moving bipedally and quadrupedally equally well. Poor pronation of the forearm, as some have hypothesized, may have limited Efraasia as an entirely bipedal dinosaur. Its gracile hands and digits were probably quite capable of grasping food items (and predatory animals and intraspecific competitors) which could then enable it to better survive its environment by adapting its diet (and defending itself more capably).

20 June 2017

Writing in Efraasia

We mentioned a number of articles, descriptions, and re-descriptions of Efraasia and thankfully there are a lot of examples of this writing hosted online in many different places. Only one of these writings is entirely about Efraasia and that is the Galton 1973 article that was previously described here. The paper (hosted on Springer's site), as many may remember, re-described a number of specimens collected by Eberhard Fraas and reassigned these specimens to a new genus named after a contraction of the collector's name; Eberhard Fraas was turned into the name Efraasia minor in this dinosaur.

19 June 2017

Efraasia in Motion?

Unfortunately Efraasia never made it, yet at least, into any documentaries, cartoons, or movies. There really are not too many movies that use Triassic animals though, so the fact that it has not been in any movies is a little less surprising than the idea that it has not been in any documentaries. Cartoon dinosaurs are typically the more famous of the dinosaurs, so its exclusion from cartoons is equally anti-climactic. The only other video online, actually, is from a young man reading about and discussing Efraasia from Stephen Brusatte's published dinosaur field guide. Barring any other videos, which I would gladly post, here is the single video that is out there:

18 June 2017

A Known Dinosaur

Efraasia is a well known dinosaur and has some of our typical webpages (e.g. Prehistoric Wildlife and Dinosaur Facts) to share facts about this sauropodomorph. These facts are read over a great set of images in the following WizScience video.

17 June 2017

Lesser Sauropodomorphs

Efraasia minor (von Huene, 1907–1908) was a gracile middle-sized sauropodomorph of the Late Triassic of Germany. The name was not actually coined by von Huene, despite the fact that he originally described the fossil remains. The name von Huene gave the remains was Teratosaurus minor; this genus is a group of rauisuchians, which Efraasia was deemed to not be a member of. The name we use was coined by Peter Galton in 1973 when he reassigned a number of specimens to the new genus named after the collector of the specimens, Eberhard Fraas. Estimated at approximately 6 to 7m (20 to 23ft), Efraasia is a respectable size for its time and place, but, as we can see, it appears to have been a rather generic looking early dinosaur; however, it is a generic dinosaur that stands out for a number of reasons that we will discuss this week.

16 June 2017

Plain Illustration

Most of the illustrations of Tarchia are fairly plain. These are mostly lateral views of the dinosaur in a static posture that shows a lot of what the dinosaur could have looked like from the side. There are not very many dynamic poses that are out there of the dinosaur that show it by itself, but this is also okay. One of the best piece of art I have actually found relating to Tarchia is a statue. The statue is a scale model of both Tarchia and Tarbosaurus engaged in one of those epic dinosaur battles that has long captivated the public audiences. The art is a collaboration between Vladimir Trush and Vitaly Klatt. Trush appears to have sculpted a number of Tarchia inspired statues.

14 June 2017

Thursday Already

The material of Tarchia is terribly incomplete to the point that size estimates of the animal are based on completely different animals, have been estimated from the smallest known remains at times, and have been independently made but not verified across a number of sources. This has made the dinosaur difficult to model in a popular context without arbitrarily picking one or another size estimate as the size of the model that will be illustrated, animated, or sculpted. It is partially this reason that there was no animated Tarchia until Dinosaurs Alive! was produced and other ankylosaurs of Mongolia were used in previous videos and films depicting that area of the world and its dinosaurs. Looking at these various estimates of size, however, Tarchia may appear to either have been the longest of Mongolian ankylosaurs with an estimated length of 8m (26ft) or a modest 4.5m (14.8ft). The upper estimate of 8m places Tarchia in the same size category as Ankylosaurus whereas the 4.5m estimate is within the range of Nodosaurus sized ankylosaurs. Basically this means that Tarchia was either a typically sized, though longer than any other Mongolian, ankylosaur or it was a smaller member of the ankylosaur family. This is important to our discussions on popular culture because the Tarchia model used in Dinosaurs Alive! appears to be of a similar size to the Tarbosaurus it is shown fighting. Tarbosaurus measures in with a range from 10m to 12m (33ft to 39ft) and even at its largest estimates this would be oversized for Tarchia.
Larger Size Estimate

Smaller Size Estimate (image by Conty)

13 June 2017

Discussing the Skulls of Ankylosaurs

There are a number of articles and citations for Tarchia. There are a lot more citations than full articles online, but there are still articles that discuss the dinosaur, so those that learn by reading are not at any kind of disadvantage this week (i.e. there is plenty of material to read and learn from about Tarchia). The most important and useful articles that exist online as full articles are possibly the most important articles in the current body of literature for Tarchia outside the initial description by Maryanska. The first is the description of the junior synonym Minotaurasaurus ramachandrani which describes what the authors (Miles and Miles) interpreted as a unique and novel cranial structure unknown before the discovery of these remains. The second article linked here today is the Arbour, Currie, and Badamgarav, 2014 that re-describes both Tarchia and Minotaurasaurus (as well as many other ankylosaurs of Mongolia) crania interpreting similarities, differences, and variations within the genus. It is worth noting that these authors mentioned that Minotaurasaurus is a fossil lacking provenance and was purchased at a mineral and gem show but has been hypothesized to have been recovered from Mongolia by Dalton 2009. The authors consolidated Minotaurasaurus as the same species as T. kielanae, but they did interpret the remains of another animal, Dyoplosaurus giganteus, as similar enough to belong to the same genus and redesignated the animal as T. gigantea; I have not looked up how this species was erased from the taxonomy so cannot offer more as to why it is no longer included in the Tarchia family tree.

12 June 2017

The Quiet Documentary Star

Despite the seemingly forgotten nature of Tarchia after the first decade or so of its known existence, that is to say after it was initially described, Tarchia managed to remain known enough that it was featured in a documentary in 2007. The IMAX movie Dinosaurs Alive! looked at the Triassic fauna of New Mexico and the Cretaceous fauna of Mongolia. The Mongolian desert scenes lean heavily on Tarbosaurus, but in its treks the large tyrannosaurid runs into a Tarchia. No hilarity ensues, but a short altercation does and it ends with Tarchia knocking Tarbosaurus off its feet and sending it into the sand.

11 June 2017

Tarchia Facts

Here is a video full of facts about Tarchia today. There are also a number of websites that contain facts about this strangely little known ankylosaur; I say strangely because during the first decade after its description Tarchia was actually fairly popular. These include ThoughtCo, the Natural History Museum of London, and Prehistoric Wildlife.

10 June 2017

Back to Tanks

©Nobu Tamura; listed as Minataurasaurus
The name Minataurasaurus is a fairly awesome name, in my opinion. Unfortunately it has been recently decided that Minataurasaurus is a junior synonym to an ankylosaur described by Osmolska in 1977 known as Tarchia. There are two species in this genus; Tarchia kielanae Maryanska, 1977 and Tarchia teresae Penkalski & Tumanova, 2016. Overall Tarchia is a fairly typical ankylosaur but the holotype name references a somewhat unique feature of the animal: a larger brain than other ankylosaurs. This may be in the eye of the beholder (Maryanska) or it may be supported by the remains of the animal; hopefully this will be something we can address later this week. The generic name comes from the Mongolian word for brain, tarkhi, and the scientific name refers to a part of the name of the leader of the 1970 Polish-Mongolian expedition that discovered the fossil, Zofia Kielan-Jaworowska.

08 June 2017

What Makes A Dinosaur Popular?

Since the discovery of Citipati it has been a bit of media darling and a very popular dinosaur with the general public. The dinosaur has appeared in books and cartoons, documentaries, movies, and shorts, and has been a very popular subject for illustrations, toys, and statues. The dinosaur's name comes from a Buddhist deity, meaning that searches for either bring up the other, only increasing the search popularity of both. We could look at any number of these outlets and even talk about the Buddhist inspiration of the dinosaur's name, but instead, we can see here how others are envisioning the dinosaur as a video game character. It does have a rather dodo-esque bill here, but it is an interesting interpretation.

07 June 2017

Continuing From Last Week

©Edyta Felcyn (Apsaravis)
Continuing where I left off last week, we can see that Citipati continues to be an animal that is often illustrated and has been studied not only for its interesting anatomy but also its peculiar behaviors. As with many of its kin the oviraptors, Citipati was an apt nest-tender and has been discovered many on separate and independent times on, in, or around its nests. Its eggs have, likewise, been recovered on numerous occasions and have even revealed whole embryos as well as hatchlings. These embryos and newly hatched oviraptors began life little taller than the average human knee (assume your own knee is within an acceptable range and attribute height differences to variation; how unscientific of me!). The adults would have been approximately 3m long and, in natural pose, approximately 1.8m tall. Assuming that the growth of these young Citipati was somewhat quick, perhaps even rapid, the combination of quick growth and the known brooding habits of Citipati says an awful lot, as we saw in papers last week, about inferences made into the history of avian style brooding as it relates to and is evolved from this maniraptoran style of brooding. The nesting position is often depicted in a singular manner, and for those not aware, this looks very much like this first image. The second image is a slight alternative, but the difference in the two images is most likely a question of heating or ventilating the nest to maintain proper brooding temperature.
©Edyta Felcyn (Apsaravis)