STL Science Center

STL Science Center

31 October 2014

The Sad Plight of Rhinos

1878 - Rashevsky, under supervision of A.F. Brant
The news recently that only 6 Northern White Rhinoceroses remain on the planet has been pretty depressing. Many sources contend that the Rhinoceros was the basis for the unicorn legend origin (others cite Narwhal tusks) but without them the parallel mat not be seen in the future. regardless, the news that the numbers of Northern White Rhinos has plummeted to a few males and females (none of which are pregnant after several attempts at mating and insemination) gave me an idea for November. This month will officially be "Ancient Rhinoceros Week".

The first Rhino, in no implied terms of evolutionary descent, is Elasmotherium. Three species make up the genus Elasmotherium: E. caucasicum, E. chaprovicum, E. sibiricum Fischer 1808 (type species). As mammalian charismatic megafauna of the last 3 million years (2.6 to ~50,000 years ago) a lot is known about these animals. In fact, so much is known that a simple weekly opening post could be a book unto itself. Instead, to keep this short, know that there are three species of Elasmotherium recognized and that they have enormous horns on their heads. We will look more in depth at them in some posts that will be dated for Saturday.

30 October 2014

Famous Displays in History

Epidexipteryx is well known in the public domain and in the scientific community. As such it is a taxon that we can comfortably call charismatic fauna. This sort of label is typically heard when discussing larger dinosaurs, birds, mammals, etc and is usually called megafauna, because of the size. Epidexipteryx, however, bucks the trend in terms of not being a large animal and instead became well known for a number of other reasons including its relatively new discovery, good press coverage, and use in the BBC's Planet Dinosaur program.

29 October 2014

Hu's Feather

Artist not credited, though it appears to bear a resemblance to the work of Jaime Headden
 The specific name for the week is Epidexipteryx hui, named in honor of Hu Yaoming, a Chinese paleontologist known for his work with mammals. When the dinosaur was described in 2008 the publication of the paper occurred shortly after the death of the 42 year old scientist. Hu Yaoming had very little to do with the dinosaur aside from it honoring him, however, his career was fairly well known and the dinosaur has gone on to become fairly famous. The skull of Epidexipteryx has not been discussed as yet, so beyond talking about the honorific name of the species we really ought to address the strangeness of that cranium. The skull has been noted to resemble those of oviraptorosaurs and therizinosaurs, to a lesser extent. The resemblance is not entirely evident or obvious, but to a point the downward curving of the mandible and premaxilla are definitely somewhat reminiscent of Citipati and Oviraptor. Somewhat uniquely, the mandible and maxilla possess forward angled teeth along the predentary/premaxilla and front of the dentary/maxilla, much like the African dinosaur Masiakasaurus. The remainder of the jaws are lacking in teeth entirely. Masiakasaurus' teeth are hypothesized to have adapted to grasping small fast prey. The similar teeth of Epidexipteryx could potentially have been used for a similar purpose and, given that the dinosaur probably could not fly (it lacked flight feathers on its wings), it probably chased down a myriad of small lizards and mammals as prey items on foot.

28 October 2014

Reading About Feathers

The paper describing Epidexipteryx was published in 2008 in Nature by Zhang et al. Rather than addressing the dinosaur as a paravian theropod the authors set out to describe what they called a new "bizarre Jurassic maniraptoran". To sum it up, Nature released a short news release that is available to the public. The article is a good read, but it is more regulated in its access. Reading the press release is a good substitute, so be sure to at least check this out!

26 October 2014

The Kids Displayed Feather

There is a rather goofy looking Epidexipteryx on a nicely organized fact page that is very kid friendly. The reason it appears somewhat odd looking is that the jaws of the dinosaur have been illustrated closed and with a rather enormous overbite. That page happens to be part of the Dinosaur Jungle site, which has been pretty reliable in the past for the quality of its information. The BBC, because of their use of Epidexipteryx in Planet Dinosaur, maintains a page on their site that details some information on the dinosaur and a short video as well.

25 October 2014

Jurassic Peafowl

The display feathers as reconstructed by paleontologists that were working on the initial description were a bit more sparse than those shown later in subsequent illustrations. However, that does not mean that these interpretations are conservative estimates or that they are inaccurate representations of the animal. The number of feathers discovered with the dinosaur is not as important as the fact that the display feathers are known to exist, though. The fact that those feathers are as large as they are also points at the exact use for which they are most often illustrated in as well. Arguments could be made for a more magpie-like situation in which the tail feathers are held directly behind the body, but the more peafowl-like version of holding the tail feathers erect is much more showy and interesting in terms of a display structure. The coloration of the feathers is, of course, all speculation at the moment. Definitive knowledge of the coloration of feathering may be in the near future though (you never know). As for the portrayed posture, it appears rather bird-like, when display postures of extant aves are considered (e.g. Northern Mockingbird). The extension of the arms of this reconstruction is more horizontal and extended less dorsal, but the idea remains the same. Were the forelimbs/wings covered in longer feathers that are not preserved with the remainder of the fossil? There exists the potential for such a thing, but as of now it has not been realized. The rostral skull of the paravian dinosaur is also quite interesting. The skull appears to have some elongation to it, though obviously not entirely like that of a beak or the typical shape of theropod dinosaurs.

24 October 2014

Epidexipteryx The Almost Bird

©Nobu Tamura
Toting a name that means "Display feather", Epidexipteryx is often portrayed as almost peacock-like.The feathers that are portrayed as such often have wonderful colors and almost distract from the small paravian body of the dinosaur. Paravian dinosaurs are small theropods that are closely related to birds, but also still related to dinosaurs, with Oviraptorids being considered one of the closest dinosaurs related to their clade. Epidexipteryx comes from the Jurassic beds of China, meaning it was temporally near Archaeopteryx and many other bird-like and paravian dinosaurs. One rather interesting anatomical feature of this dinosaur is the strange shape of its lower jaw, which we will look at in further detail this week. Also, we will look at its unique fingers and those rather ostentatious tail feathers as well.

23 October 2014

Ultimate Fame

Usually when a paleontologist is immortalized in the name of some taxon it is as part of the specific epithet. Once in a while paleontologists are remembered at the generic level (e.g. Drinker, Othnielia, Bennettazhia) or animals are named after family members (e.g. Timimus, Leaellynosaura). Gasparinisaura falls into the former category, being named after Zulma Brandoni de Gasparini, one of the premier female paleontologists of South America. Does being named after the second woman to chair the Paleontological Association of Argentina make the dinosaur famous all on its own? How well known, in North America, is Zulma Brandoni de Gasparini honestly? Regardless, there is a rather tiny South American dinosaur named after her and it is famous because it is tiny, named after a famous paleontologist, was on television, and was even featured in a dinosaur "how to draw" book. It is a rather wonderful little dinosaur and well known all over. Gasparinisaura has also introduced a renowned and well rooted Argentinian paleontologist to people unfamiliar with her career.

22 October 2014

Short and Light

Gasparinisaura was a short dinosaur at about 1.7m (5.6ft) in total length. The height of the dinosaur was probably less than that, measured at the hip. The compact body was approximately 13kg (28lbs) according to some estimates. These small measurements were made off of the light bones of the body, including the skull. The forelimbs were noticeably lighter than other members of Gasparinisaura's family tree. The pelvis is also lightweight, small, and the femur was shorter than the tibia and fibula. The quadratojugal attaches to the squamosal, a basal trait, which helped assign its place on the family tree. The gastroliths in the fossil, while not important in placing it the tree, have so far been counted at approximately 140 polished round stones that accounted for approximately 0.4% of the total weight of the dinosaur.

21 October 2014

Written Dinosaurs

Gastroliths in dinosaurs are well known from many different genera and many different time periods. They are somewhat rare, as are all fossils, but they are most definitely well known. Gasparinisaura are one of those dinosaurs that have well documented gastroliths. In 2008 those gastroliths were discussed by Cerda. His paper describes the stones, their purpose, and the implications they provide to the diet of Gasparinisaura. The image at left is from the paper and has been released on Wikipedia. Cerda is a professional when it comes to Gasparinisaura. He also had a hand in describing the microstructure of Gasparinisaura bone in Cerda and Chinsamy (2012). The original knowledge of the dinosaur came to the general public through the work of Coria and Salgado (1996), but new material has been unearthed since that time. That new material was again described by these two scientists, but in Salgado et al. (1997). The latter two papers kind of speak for themselves and do not need to be detailed ahead of time.

20 October 2014

Under the Feet of Giants

Planet Dinosaur almost features Gasparinisaura in its 5th episode. However it does not actually feature Gasparinisaura but it does feature Argentinosaurus. Under the feet of Argentinosaurus lived small dinosaurs, quickly darting in and out under the larger dinosaur's body. Those dinosaur do appear in the show and they happen to be Gasparinisaura. So far this entire paragraph has been a very convoluted way of saying that Gasparinisaura shows up in Planet Dinosaur as a speck beneath the lumbering giant that is Argentinosaurus. We should probably just watch it scurrying around rather than talking about it.

19 October 2014

Gasparinisaura's Lonely Link

Gasparinisaura appears on the internet very sparingly. We do have three quality sites that address our three normal levels of reading ability. The Dino Directory addresses the lower level readers and supplies an illustration and size comparison. Enchanted Learning actually rests in the middle level position with more detail taxonomically and guides for pronunciation. The third level is adequately filled by the Dinosaur Wiki. That page details more about the discovery, anatomy, and properties of the dinosaur. Unfortunately, that is where our road ends in the pursuit of educational links. There are no coloring sheets or videos for today.

18 October 2014

Looking Basal

©Nobu Tamura
Ornithopods all have a similar look to them. Basal ornithopods are no different in that respect. They exhibit primitive and derived traits, but they all have a fairly basic body plan that can be generalized as typically facultatively (at least) bipedal with a beaked face and a body that suggests that running is the primary defensive tactic of these animals.Safety in numbers may not have been their only defense, but for now it appears to be the only one we know of. This is, of course, partly due to the fact that there are not many remains from the known individual and that that one is fragmentary to begin with. However, it is important to note that there does not appear to be much in the way of novel traits that stick out in Gaspirinasaura's body plan.

17 October 2014

Gasparini's Dinosaur

1992, Argentina. Like so many other stories in recent paleontology this dinosaur's discovery happens in Rio Negro Province of that country. The dinosaur was described in 1996 and named after famed Argentine paleontologist Zulma Brandoni de Gasparini by Rodolfo Coria and Leonardo Salgado. Gasparinisaura cincosaltensis (named for the location Cinco Saltos) is a small bipedal ornithopod that has been placed as a basal euornithopod. This dinosaur is fragmentary, but the fossils did contain gastroliths, which are always a welcome addition to fossil evidence as they impart many behavioral and dietary implications to the researchers.

16 October 2014

First Dinosaurs

Saltopus was famous at some point but is not famous anymore, not as famous as it was before at least. The videos that we saw earlier in the week exist, as do the numerous websites we saw. There are, however, little to no remaining pieces of evidence. That has not stopped people from knowing about Saltopus. Part of the reason that it is known is that it has lived on through literature, including a small book called Saltopus and Other First Dinosaurs. This book is a pretty good introduction to Saltopus, but it does contain a somewhat unsubstantiated remark about the hunting habits of the dinosaur. However, rather than tell you what the book says, you should all check it out.

15 October 2014

Weak Bones

The partial skeleton of Saltopus is mostly gone at this point. The skeleton was not that great to begin with actually. The original material consists of a partial vertebral column, pelvic girdle (which contained an ancestral two vertebrae and not the novel trait of four), and partial remains of both the fore and hind limbs. The skull, unfortunately, is completely missing from the holotype. That material, also, is the only known material to date. The majority of that material was originally preserved as casts (or impressions) in the sandstone of the Lossiemouth Quarries.

14 October 2014

Fees All Around

In the future it may be possible to read Cambridge Journals articles at home, without subscription or access to a library with access, but that day is not today. That is okay, despite when I complain about the cost of single articles. I do frequently wonder how many people drop $45 on single articles, but it must happen now and again considering the price remains. That being said, it is wonderful when articles are online, regardless of how old it is. The original von Huene article is available online through the Cambridge Journals site (though articles that old are typically much more widely available and disseminated online). An article 100 years after von Huene's description and naming was written by Benton and Walker which revisits and redescribes Saltopus. To make a long story short, for those that cannot read the articles from home, Benton and Walker (2010) stated that: "[Saltopus is] one of a radiation of small pre-dinosaurian bipedal archosaurs in the Triassic found so far in North and South America and in Europe."

Benton, M. J., and Walker, A. D. 2010. Saltopus, a dinosauriform from the Upper Triassic of Scotland. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 101(3-4), 285-299.

13 October 2014

Dinosaur Days

There is a software program out there online known as Dinosaur Days that is not entirely free, but some times the videos from the site are either leaked or put on YouTube by the company that puts out the software (there is a difference). Regardless, the site is kind of partially interactive encyclopedia of dinosaur information and the videos that the writers have put together are well modeled, cartooned, and illustrated. The information in the videos is also well put together. Lacking a documentary on most dinosaurs I would highly recommend the site, if it is affordable. However, today that is not a worry as the video for Saltopus is available for viewing without a subscription:

12 October 2014

Cannons and Videos

Zander and Kevin Cannon
Big Time Attic is not the only site that has links concerning Saltopus. This only adds to the plethora of sites including Kids Dig Dinos, KidsDinos, and Enchanted Learning. The largest problem with the three sites is that they differ slightly in the systematics that are referenced. Rather than going over each individual site reading is definitely encouraged. There is also a video that gives you some cursory knowledge of the dinosaur from the dinosaur itself. Enjoy I'm a Dinosaur: Saltopus.

11 October 2014

Typical Bodies

The body of Saltopus has been highly generalized. In part this is because many of the bones were degraded or destroyed in the recovery as much as during the preservation of the dinosaur. All indications of the known body imply that the dinosaur was small, agile, and very basal. In fact, the animal is considered basal to the entire Dinosauriformes clade. This places it at the bottom of the tree branch on which all dinosaurs sit, both saurischian and ornithischian. It has been placed in the past as an advanced theropod and as a sister to herrerasaurs.

10 October 2014

von Huene's Lesser Known Dinosaurs

Friedrich von Huene named many dinosaurs during his career. In 1910 he described a Triassic dinosaur that had been discovered by William Taylor in a quarry in the quarries of Lossiemouth, Scotland. The dinosaur was a small bipedal carnivore with bones that were light and hollow like those of birds. The location of the quarries was near the town of Elgin and the dinosaur itself appears to have gracile limbs and all of these things put together gave von Huene the name for his animal: Saltopus elginensis (loosely translated Jumping foot of Elgin). The known material is not well preserved, but more on that later!

09 October 2014

The Quieter Chasmosaur

Anchiceratops is a very popular ceratopsian. It is not well known by the public though. This is a well studied dinosaur and is the subject of many books and book chapters and has appeared in at least two episodes of the popular cartoon Dinosaur King. We saw one of the episodes on Monday but there are still plenty of things we haven not seen, like the cards that have been designed for the collectible card game. There are also toys of Anchiceratops circulating in the dinosaur toy sphere. The toys are generally well representative of Anchiceratops as well. This is not always the case remember. One of the best representative toys has a good write-up on the Dinosaur Toy Blog. Personally, I am impressed that they even included the medially oriented bone knobs on the frill of the dinosaur. It is a well modeled toy that represents the animal well and gives those kids (and adults) playing with them a very accurate portrayal of the dinosaur that they are seeing. That is very important in the end. The purpose of toys is fun, of course, but it is also indirect education and modeling of prehistoric animals in general.

08 October 2014

Suppose and Assume

©Nobu Tamura
Taking after Paul, who made the estimates of body length and size, we can assume that the specimen he used, NMC 8547 (Canadian Museum of Nature), represents a postcranial skeleton of Anchiceratops. Assuming it does, we have a vertebral column of 74 bones. The neck is short in comparison to many other dinosaurs, but is considered long for a ceratopsian, containing 10 vertebrae. There are 13 dorsal and 12 sacral vertebrae composing the trunk and pelvis of the animal. The tail is also considered short at 39 individual elements, some of these are also found in the pelvic region though and are not dedicated tail bones. The average known chasmosaur (the family of Anchiceratops) is built different with 12 dorsal and 10 sacral forming the trunk and pelvis and up to 46 caudal vertebrae forming the end of the pelvis and tail. Ceratopsians, like many other animals, have fused vertebrae in the pelvis (known as the synsacrum) as well. It has been suggested the synsacrum of this specimen was oriented posteriorly compared to other chasmosaurs and that the trunk was not necessarily of a different length, just arranged differently. The pelvis is actually considered to be elongate also. The forelimbs are robust, another trait we consider normal for ceratopsians. It can probably assumed that the hindlimbs are also rather robust.

The frill we briefly mentioned already. The frill is covered with "epi" bones that are named for the bones from which they originate (or that they sit on, if that is more accurate) and include episquamosal, epiparietal, and epoccipital. To be completely accurate in describing them, these are osteoderms, meaning that they developed from bony deposits of the skin and not in the same manner as the squamosal, parietal, and occipital that they are all attached to. Anchiceratops also possessed bony knobs medially located on the parietosquamosal frill. These are varied in size and shape on individual animals. They are probably entirely unique to each individual rather than being an artifact of imperfect preservation.

07 October 2014

History In Play

Barnum Brown
As a history major during undergrad I thoroughly enjoyed reading personal accounts and the language of the early 20th century and earlier. It always makes my day when I can find original accounts from the past so that others can read them. Sometimes they are not highly descriptive or well written (probably in part because of the massive influx of fossil materials from the North American West during those years). Barnum Brown's description is fairly well done, though it does lack a little here and there. The massive amounts of photographs and comparative line drawings fill in a lot of the gaps though. In more recent times Jordan Mallon and Robert Holmes have spent a great deal of their time redescribing postcranial remains and variations in Anchiceratops. If the book, a great tome on ceratopsian dinosaurs with a plethora of wonderfully authored chapters, is not available to you online, and neither is the JVP article, then I encourage the readers to get out there and find copies of either one used somewhere. I realize that that is not very helpful, but it is the best advice and both the chapter and the article are worth the time taken to find them and read them.

06 October 2014

Two Timer

Apparently Anchiceratops is one of only two dinosaurs (Carcharodontosaurus being the second) to appear in the Dinosaur King cartoon twice and in the same city both times. Anchiceratops like Paris according to the Dinosaur King creators. One of the episodes is online. Enjoy watching it this evening. There are no documentaries or anything else, but a good cartoon is easy to enjoy.

05 October 2014

Slap Fight!

The links abound for Anchiceratops at different levels of reading complexity and ability. As usual when we have a lot of links we can set up a gradient of complexity in the links. These range from very simple with simple listed facts to short paragraphs. Sites like KidsDinos mixes listed facts, images, and some short reading passages. The encyclopedia at Science Kids does a good job of bridging that remaining gap between listed facts and short paragraphs. If that handful of links does not interest younger scientists into checking out Anchiceratops more, maybe this strange slap fight would be something they could get into:

04 October 2014

Many Horned Faces

The sheer number of ceratopsian skulls can be perplexing when it is noticed how few have postcranial bodies. In terms of overall fossil numbers Anchiceratops is fairly well represented and this gives a fairly good picture of what the animal looked like for illustrators to begin their interpretations with. The most interesting aspects of ceratopsian illustration, in my mind, have always been the beaks and the frills. The horns do wonderful things in some illustrations and bodies are never too far from the average ceratopsian body, just like interpreted hadrosaurs.

Anchiceratops of Horseshoe Canyon Cretaceous Craig Dylke 2013 under Creative Commons license 3.0
One of my favorite interpretations so far this week has been Craig Dylke's underwater Anchiceratops. In part this is due to the scene but also because the beak on his animals is enormous and it makes me wonder what exactly a version of this animal that fed on soft underwater grasses like a hippo or manatee would need so much keratin for. Granted the beak itself is not indicative entirely of what was eaten or how much sheering power there was on that part of the jaw, but it seems like heavy machinery in a soft food world. Either way, the idea that some ceratopsians may have been hippo-like has been courted a number of times in the history of our knowledge of them and it is always interesting to see them interpreted as such.

©Mariana Ruiz Villarreal
The tried and true interpretation of a terrestrial ceratopsian is always welcome of course. The highlights here are more on the subdued ornate frill of the skull. The triangular edges of the frill are covered in soft tissue here and, despite the angle, that tissue appears to really downplay that ornamentation. The horns are average horns for the dinosaur and the beak is a very ceratopsian beak. The illustration is not boring or just the average ceratopsian splashed with the name Anchiceratops, the dinosaur is just, potentially, that average looking. It is pretty amazing how non-fantastic dinosaurs could have been, and that is why illustrations like this that show them as "mundane" looking animals are important and pretty fantastic in their own way.

03 October 2014

Near Horned Faces

This entry is backdated to yesterday. Yesterday was a long tiring day and I wasted the evening away in a video game. Sometimes you have to turn off the brain.

Image Credit: Wikicommons user FunkMonk
There are times when I talk about similar dinosaurs that no matter how much I searched the blog I find myself amazed that I have not discussed that dinosaur before. That is the case with a healthy number of the ceratopsian dinosaurs that we discuss, and this week is no different. We will delve into the realm of a horned dinosaur known as Anchiceratops. One species is recognized (Anchiceratops ornatus Brown 1914) and a second species (Anchiceratops longirostris) was synonymized years later. This quadruped is from an earlier time period than its relative Triceratops and was a little smaller, with estimates topping out at around 16.4 feet (5 meters) long and girth estimates figuring it for a much lighter ceratopsian. An estimate of weight by Greg Paul comes in at approximately 1.2 tonnes; Triceratops is estimated between 6.1 - 12.0 tonnes. The parietalsquamosal frill was very ornately laid out, giving us the specific epithet of ornatus. Little is known about the postcranial body and most images fill this in with the idealized chasmosaur body type, making it look fairly recognizable and vaguely bovine. This dinosaur was discovered in 1912 by Barnum Brown and papers are still being written 100+ years later (the most recent was published in 2012).

02 October 2014

Video Games, No Books

We saw Stokesosaurus in a video game earlier in the week. The dinosaur does not appear in any popular type texts though. No children's books specifically mention the small tyrannosaur. Popularized technical and almost technical literature do discuss the dinosaur, but not often. There are not even any toys of Stokesosaurus. Soon I am going to have to change the popular culture day of the week to something else! The dinosaur is illustrated often, including in this poster sized image of the tyrannosaur family by Robinson Kunz of Germany.

01 October 2014

Short Autapomorphies

Stephen L. Brusatte and Roger B.J. Benson Creative Commons Attribution 2.0 Generic
The single autapomorphy of Stokesosaurus is found on the ilium on both specimens. Yes, I did say yesterday that there was only one recognized specimen, however, there is a supposedly juvenile ilium that is attributed to Stokesosaurus. Both ilia are marked with a ridge from the superior to the inferior edge of the ilium. That ridge angles posteriorly along the surface. Highlighted line drawings of the specimens make that ridge look like an upside down Y embossed on the outer surface. The anatomy as inferred by many different researchers is considered to be heavily tyrannosaur influenced though the basal body plan was probably a lot more gracile and agile than the later and more advanced larger tyrannosaurs.