New Year Fossil

Before discussing this week's fossil I would like to say it has been a lot of fun to work on this every day (with a few exceptions now and then) for the past six years. We have discussed more fossil animals than I care to catalog, which may have been a better idea early on so that I know what animals we have already discussed and when. It is a little difficult to remember all of the animals that we have talked about sometimes considering there are well over 2000 posts recorded.

This week we will start off the new year a little more slow and relaxed than normal with one of our favorite Xenarthan fossils: The Giant Ground Sloth. Specifically we will discuss the genus Megatherium, one of many genera of giant sloths that includes seven species, most notably the type species M. americanum Cuvier 1796; one of the first fossils scientifically described by Georges Cuvier. Ground sloths like this were once common on the plains of Pleistocene North and South America. The sloths made it to North America after they migrated across the Central American isthmus from their native South America and were one of the very few South American taxa successfully survive the influx of North American taxa when the isthmus opened up. Typically depicted on the plains eating from solitary trees, Megatherium was also a forest dwelling animal. Expect to see some sloths in the forest as well as on the plains.

©Jaun Bautista Bru

Pictures Worth Many Words

Art imitates life to the best of its ability when it comes to fossils. We know with fossils that this is not always simple and of questionable accuracy. In the spirit of loving art for art's sake today I want to simply put a number of interpretations of Allosaurus together below without muddying the waters with my own interpretations or criticisms of the images. Instead, this can be done by the readers either within your circle of dinosaur loving friends or to inform your own artistic endeavors, or you could just enjoy some fanciful, interesting artworks that depict a very famous dinosaur. It is your choice. Also, I had to include the photo below because I took this panoramic shot in Utah during SVP and I do not think I shared it with many people.

©Franco Tempesta

©DK Eyewitness

Famed Dinosaur

As you may have noticed, I did not write yesterday; I let time get away from me and just never got around to it honestly. However, if you thought you would miss a lot of material on Allosaurus anatomy, you just have to look back at this post from a couple of years ago that addresses some of this topic.

Allosaurus is one of the most well-known predators following the likes of Tyrannosaurus and Spinosaurus from the dinosaur world. We know, from earlier in the week, that Allosaurus has made its mark in documentaries (and hypothetical documentaries) as well a research and a number of websites. Alone, these would be a good foothold for most dinosaurs to gain more popularity and have more interesting things to say about them and links to pages that discuss them. Allosaurus has also appeared in movies, but, more importantly to us today, in massive numbers of books, magazines, and as toys. Books are easy to come by that mention Allosaurus. There are  large quantities of information in books like The Princeton Field Guide to Dinosaurs and many other books that are geared more toward a younger audience, like Dougal Dixon's book Allosaurus and other Dinosaurs. Searching for Allosaurus kids books returns a list that can take a very long time to sort through; do so at your own peril in terms of time allowance.

Allosaurus has appeared in both the historical versions of magazines (meaning print) and digital magazines like Live Science. Technically the Allosaurus shared in this article for Live Science can also be attributed to the blog world (as it comes from the Witmer Lab's online presentations), but that is, I would argue, a new version of digital magazine.

I do not want to spend all day writing about toys, so simply know that the sheer number of Allosaurus toys is much higher than expected and range from old outdated versions of the dinosaur to new, feathered versions of the dinosaur.

News About Allosaurus

Allosaurus appears in a lot of research and therefore in a lot of papers. The dinosaur also appears in a lot of books, but we will save those for Thursday. Allosaurus has been the subject of finite element analysis, ontogenetic studies, and even intercontinental presence of the genus. There is even a paper that describes the injuries and pathologies of MOR693, more colloquially known as Big Al. Four papers should be plenty to learn more about Allosaurus. If, however, that is not enough Allosaurus papers, there are a number of papers presented in this post from two years ago on this blog.

Documentary Star

Where Tyrannosaurus is a full on movie star, Allosaurus is a documentary and television dinosaur phenom. Despite the number of appearances of Tyrannosaurus on television being considerable, lately the majority of documentaries have spent what appears to be a majority of their time discussing and showing Allosaurus instead. I have a few favorites in this group of documentaries, but not all of them are considered as scientifically accurate as others and as such I will only share a couple of the more widely accepted documentaries. The first video comes from BBC's Dinosaur Planet. The facts that are presented are typically seen and heard facts, however, the illustration and the sinister look of Allosaurus in this portrayal are what have really drawn my attention. This kind of representation is usually described as skin and bones interpretation and is often frowned upon as it ignores underlying muscle structures. Despite this problem with the reconstruction, the anatomy of the dinosaur is highlighted and discussed and, for anyone that has seen the skeletons of Allosaurus, this interpretation leaves the skeletal anatomy that is discussed easily seen in the animated recreation.

One of the better fleshed out versions of Allosaurus (though certainly not the absolute best) comes from the Walking with Dinosaurs special about an Allosaurus named Big Al. The reconstructed and animated version of Big Al is based on a skeleton housed and mounted at the Museum of the Rockies that contains a number of interesting pathological deformities and marks of skeletal repair. This more fleshed out reconstruction is important in that it adds some muscular tones to the body. The pathological conditions are hypothetically imposed on the dinosaur throughout its life during the documentary as well, allowing us to see changes in the reconstruction over the life of the dinosaur; this is an interesting and unique aspect of this particular interpretation of a dinosaur in a documentary. As such, this is a large reason that this video(a short clip from the documentary) is being included today.

Facts for Christmas

Because I know a lot of people are busy with major holidays or family time this weekend, I am going to post two videos with facts about Allosaurus rather than posting a long-winded entry today. These are okay videos but enjoy your family today. Enjoy that time watching dinosaur videos, of course, but enjoy time with your family for sure.

One More Week in December

The second half of the dinosaur calendar this month is a dinosaur that is closely related to last week's Barosaurus in many ways, including environment, the era in which it lived, and their interactions with one another. The most important interaction between the two dinosaurs was, most likely, that of a predator-prey relationship. Allosaurus often came into contact with Barosaurus and, some of those times, Allosaurus managed to feed on Barosaurus. The sauropod, as we saw last week, was enormous, so Allosaurus would have had a difficult time bringing down and eating its counterpart. The image of the two dinosaurs floating in space peacefully tethered together may be unlikely, but the lives of these two genera of dinosaurs were tightly intertwined and seeing a different view of the dinosaurs interacting is fun as well as interesting.

©Brynn Metheney

Gurche's Barosaurus

The entry hall to the American Museum of Natural History (AMNH), the Theodore Roosevelt Rotunda, is centered around a Barosaurus rearing up and facing an Allosaurus. The scene has been captured in a John Gurche painting that accompanies the entryway skeleton mount. Dinosaur art aficionados may remember John Gurche's work from such places and works as the Field Museum (the Sue mural), magazines and books (Boy's Life and The Dinosaur Heresies cover feature the same artwork). The painting in the entryway to the AMNH is equally iconic and, like many of Gurche's paintings, has a certain style to it that is unmistakable. Whether what brings it to life is the crisp detail of the skin, sky, or supporting elements of the background differs between viewers, but the beauty of Gurche's dinosaur paintings (and his sculptures) is hard to argue against despite their now "archaic" appearance. Unfortunately this piece has made its way around the internet since 1991 and I could pull it down from almost literally anywhere online and paste it onto this page. Out of respect for John Gurche I would rather post a link to the image on his page and a second link, for the painting on Pinterest as a secondary link to see a larger version of the painting. Facebook readers will see the painting as the icon for the link.

Making It Popular

There is no solid reason, just looking at Barosaurus, as to why it has become such a popular dinosaur among dinosaur enthusiasts. Barosaurus does not have the largest body, teeth, claws, or any strange cranial adornments (that we know of). There are also no movies, documentaries, or cartoons directly associated with the dinosaur. As one of the most prominent of Marsh's dinosaurs, Barosaurus became popular mainly because it was known early in the boom of North American dinosaurs. It helps that a great deal of speculation, testing, and discussion has been generated about and around Barosaurus since its discovery. This has led to the creation of illustrations, schematics, written works, and a variety of other works that further the self perpetuating popularity of the dinosaur. It doesn't hurt to be this enormous either:

The Tall Tale

Barosaurus has interesting anatomy for a sauropod (typically long necks and tails, and fat bodies are all most people think about when they see these animals. One of the most interesting things about Barosaurus is actually the size of its neck and tail. Among diplodocids, Barosaurus is thought to have one of the longest and fattest necks in the family. This has led to some of the discussion about circulation and blood pressure that has been so central to the research that has been done on Barosaurus over the years. The tail of the dinosaur is equally long, though not considered to be fattened or wider than usual. Despite both of these enlarged or elongated features, one of the hallmark restoration characteristics of Barosaurus is not either of these features, but rather the sauropod's ability to rear back on its hindlegs to defend itself from predators. Assuming that the dinosaur had the agility and strength to do this, one of the longest necks and longest tails of its age rearing back and slamming down on its antagonist would be an effective weapon of self preservation. Equally useful would be the long whip-like tail and also the ability to hit others in a very giraffe-like manner. At the moment, the rearing Barosaurus is by far the most popular incarnation of the animal; however, other representations of the animal defending itself may someday appear as well.

©Fred Wierum (CC BY-SA 4.0)

Old Information and New Information

The earliest results of a search for papers discussing or describing Barosaurus date back to 1919 (and before, but the earliest result in search is 1919). This Richard Swan Lull book, a redescription of the type specimen housed at the Yale Peabody Museum, is available in its entirety from Google; all you have to do is sign in. A description of any kind is beneficial to understanding the anatomy of the dinosaur in question. I recommend skimming, at the very least, this book to better know Barosaurus and the anatomical systems that were important to the dinosaur's survival. Closer looks at individual systems or specific anatomical modules have been conducted in Barosaurus as well. These include hypothetical cardiovascular system functions, cranial circulation, and neck postures and blood pressure. Blood flow in a long-necked sauropod is certainly an important topic and the papers here reflect that importance accurately. There are also papers concerning the idea of multiple hearts in Barosaurus and discussing the tail of the dinosaur as a supersonic weapon. However, these papers are not centered on Barosaurus and are somewhat less informative.

Barosaurus Showing Off

Barosaurus has not appeared in any movies but it has appeared on television, in video games, and makes many appearances in home movies (which is what YouTube basically is) because it is a popular museum and amusement park mount. The Royal Ontario Museum released a video with David Evans discussing their Barosaurus mount and the location from which the first skeletal remains of the sauropod were recovered that is shared below.

Kid Friendly

Barosaurus is a very kid friendly dinosaur. There are fact pages all over the internet ranging from more amateur sites like KidsDinos to the borderline professional web pages of About (no offense to Bob Strauss' quality entries for these fact pages). KidsDinos has been radically changed in the last few months and Barosuarus' page looks quite intriguing. Barosaurus has made enough of an impact to make its way into the DK Eyewitness books and DK Find Out websites such that it features prominently on their dinosaur fact pages. Fact pages, well written, listed facts, or interactive displays notwithstanding, abound for the dinosaur, but Barosaurus has also shown up in popular video outlets, even appearing as a dinosaur of the day for I Know Dino, a regular dinosaur related podcast.

Ending the Year in Fashion

The dinosaur calendar ends the year in a big way. Instead of a single animal to close out December we have two well-known and previously discussed dinosaurs to cover over the next two weeks.  The animals in question fit my normal predator/prey cycle of choosing topics which is convenient, and they also go together in discussion as well because they have a shared ecology. This week we will discuss Barosaurus, a large Jurassic sauropod known from deposits in Utah and South Dakota. This 20 ton, 26 m (85 ft) sauropod dinosaur was a member of the diplodocid family of sauropods and possessed a neck composed of up to 16 cervical vertebrae and a tail of upwards of 80 caudal vertebrae. The skull of Barosaurus is so far unknown, but has been rebuilt for museum displays using skulls of Diplodocus and other relatives of the dinosaur as blueprints.

©Brynn Metheney

The Modern Tyrannosaurus

Modern illustrations of Tyrannosaurus have included feathers for a fairly long time but even prior to the inclusion of feathers Tyrannosaurus was ever evolving in its illustrated representations. The amount of feathering changes depending on the artist and their interpretation of the extent to the amount of feathering that covers its body. There are two extremes of feather coverage which should be considered: A very light feathered body that has very small patches of downy feathers and the extensively puffy feathered model. The truth of Tyrannosaurus feathering almost definitely sits somewhere comfortable between the two extremes. Seeing the  extremes, however, allows us to feel a little less critical about the middle ground. There may not be a lot of scientific data supporting that but it has been a rather consistent observation in my experience. However you may feel about Tyrannosaurus feathering, enjoy the two different interpretations shown below for what they are worth.

©RJ Palmer

©Damir G. Martin

Tyrannosaurus Popularity

We all know that Tyrannosaurus is a very popular dinosaur and the list of known attributes of the dinosaur, both anatomical and ecological, is growing regularly. The literature, professional, amateur, and popular is immense and it too is growing regularly in all areas. I contemplated putting the list of all of the resources that could fall into those categories, plus movies, toys, and other popular culture online, but the list is so enormous that this blog post would take days to read. Instead, looking for Tyrannosaurus on one's own, you the readers could be just as busy and find links that I would not necessarily put on this blog. What I do want to share today, that someone would find but that might not been seen regularly, is this video, which shares a lot of images of the dinosaur gathered from popular sources:

Tyrannosaurus Anatomy

The general shape of Tyrannosaurus is known to everyone that has ever seen anything labeled as a dinosaur. The dinosaur itself is more complicated than its general outline of course, and this is a very important distinction to make; not every dinosaur shaped like Tyrannosaurus superficially is in fact T. rex. The hypothesized anatomy of Tyrannosaurus has recently been the subject of a National Geographic documentary and, despite my enthusiasm for describing all of that anatomy, a great mock-up has been done for me already. The key to watching a documentary like this is to remember that, though the anatomy is based on hypotheses, these hypotheses have been tested in various ways for many many years and they are mostly based on extant members of the extended Tyrannosaurus family; these include inferences developed from crocodylians as well as birds.

Tyrannosaur Paper Trail

The study of Tyrannosaurus has been conducted across fields, disciplines, and a rather immense amount of time (considering the field of paleontology). This is a normal situation for an animal that is intriguing for a variety of reasons. Many of the reasons that Tyrannosaurus are intriguing is the mysterious nature of so much of its anatomy. The biomechanics of running and walking, feeding, the skeleton as a whole, and Tyrannosaurus forelimbs, for a few simple examples, have been discussed and studied intensely for years and the emerging pictures of how these systems interacted is now showing a complex animal with amazing capabilities and life history. Recent advances in science have allowed us to look at not only the skeleton of this (and other) dinosaurs, but also the soft tissue, which is revealing even more about Tyrannosaurus that is awe inspiring and astounding. These soft tissue analyses have included studies of cellular preservation as well as protein analyses. These practices have led to findings that suggest the reproductive state, and as such corroborate sex determination based on skeletal tissues, of T. rex specimens based on soft tissue evidence like medullary tissues. Such analyses have not been without critics and this is to be expected as skepticism is a way of life in science.

The Veritable Movie Star

Tyrannosaurus rex appears in more movies, documentaries, and other film roles than any other dinosaur or fossil creature. There are a few that come close (e.g. Triceratops, Stegosaurus) but none of these possesses the "star power" of T. rex. Some of the best Tyrannosaurus representations in film are some of the oldest, but these do not always hold up in terms of the image of the dinosaur that we expect to see because of the changes in the scientific appearance that have been uncovered recently. There are, because of that, also good modern illustrations or depictions of Tyrannosaurus that may not be in the best documentaries or movies but are beautiful to look at. As a villain, possibly one of the best Tyrannosaurus feature cartoon roles was as the protagonist in the 1980's cartoon The Land Before Time.

Despite the inaccuracies of the illustration, though it was fairly on point in its heyday, this Tyrannosaurus accomplished the goal of looking and feeling like a terrible presence that not only brutally attacked another dinosaur early in the story, but also came back to stalk and haunt the young heroes of the story throughout their journey. The single-minded quest for these tiny morsels seems a bit ludicrous, but it does serve to drive the story. In the vein of antiquated dinosaur representations is the original King Kong's Tyrannosaurus. This version of the dinosaur is one of the more entertaining stop-motion/puppet representations of the dinosaur that has graced the screen. Terribly rendered with three fingers and its tail dragging all over the screen, this T. rex is an embarrassment to its kin, but it is also one of the first that the public was introduced to and is quite an achievement for stop-motion animation.

The only newer movie I am going to leave here is actually fairly old as well. There are plenty of new Tyrannosaurus attacks on film in modern and ancient scenes. One of my favorites of all times is the initial attack in 1993's Jurassic Park.

Factosaurus

Popularity makes writing this almost farcical with some dinosaurs; I could easily just place links and videos in here all day long with a dinosaur like Tyrannosaurus and spend no time at all working on the post. However, there is no fun in just posting videos and not getting to discuss them at all. Many fact pages exist for Tyrannosaurus; Google lists an abbreviated version of a fact page on its front page of results when searching for Tyrannosaurus facts. There are a number of issues with that front page including the illustration of Tyrannosaurus and the capitalization of "Rex" among other issues. There are a few high quality fact pages that need to be highlighted. The first page I am sharing is the University of Manchester Museum's page describing and discussing the mounted skeleton (cast) of a Tyrannosaurus known as Stan that is housed in their display hall. Their description goes beyond the mount itself and discusses some scientific studies concerning not only Stan but all tyrannosaurs and the findings of those studies. This is important for our younger readers because it shows not only facts about a dinosaur, but some important results of intense scientific inquiry. ScienceKids, the encyclopedia hosted in New Zealand, hosts a long lists of facts about Tyrannosaurus that lists all kinds of different facts about the dinosaur that have been collected from throughout the known results of Tyrannosaurus research over the last 100 plus years. The last page that I want to specifically mention is Kids-Dinosaurs. This site not only has posted a significant list of facts, but has made those facts interactive and illustrated the facts with informative artwork, graphs, and photos of fossils. The video I think is most worth watching for entertainment purposes is the always popular cartoon series I'm A Dinosaur, shared below. I will save some other videos for later on in the week.

Missed Dinosaur?

©Everything Dinosaur

I looked back over my posts and I know that at some point, in the older version of this blog, I had covered Tyrannosaurus rex. However, in the new version of the blog there is no entry present for T. rex, let alone an entire week's worth of entries. Therefore, in the spirit of the holidays, and because we are coming back off of a week away during which I was working on my research exclusively, I bring you the holiday T. rex. Tyrannosaurus is an interesting dinosaur in part because it is an immensely popular dinosaur and that has shaped its public image as much as the science behind the dinosaur itself. Also, because the dinosaur is so popular with the public and scientists alike a lot of research has been done on, around, and to explain the dinosaur so that we all know as much as we do about T. rex. This week we will discuss T. rex and I will attempt to pick the best scientific tidbits that have come to light since the last time that Tyrannosaurus was featured on the blog. There has been a lot of interesting science since that time, so hold on tight and get ready for some really intriguing science this week as we discuss one of the most famous dinosaurs ever!

Back Next Week

My apologies folks. I've been considerably busier the past week than usual and haven't had time to write here. I'll be back next week, but for now, here's my excuse note for not writing!

Lizard of Yunnan

Yunnanosaurus is a special prosauropod. Facultatively bipedal and sporting sixty spoon shaped teeth, this was a dinosaur well adapted for its world and solidly laying the evolutionary body frame for the giants that would be its descendants (some speculation included here). One of the strangest things about the animal is the almost absolute lack of quality illustrations. Many, even most, of the illustrations of this dinosaur are the textbook quality pre-1980's style drawings, such as the one below. This is interesting and confusing because there is indeed a wealth of fossil information about the morphology of this dinosaur. If anyone wants to contribute a better drawing or knows of one I think we would all benefit greatly. It is, however, fun to note the antiquated dinosaur art that is out there. This version of Yunnanosaurus has frog-like thighs and a snake-like tongue that make it more ridiculous than accurate while at the same time underlying the problem that Yunnnosaurus, despite its popularity, suffers from: namely a lack of illustrations and interpretative materials.

Scholarly Fun

Yunnanosaurus has been written about extensively. The most important papers are the papers that describe various aspects of the fragmentary prosauropod. There are fewer articles exploring aspects of functional morphology and other aspects of paleobiology, but we can ignore this lack for the most part as the descriptions more than keep us occupied in terms of pages for reading and pure content. Young's original description is online but can be difficult to access. In contrast Sekiya's description of a new species, Y. robustus, is easier to access and read online. Those interested in just the skull may, instead, find Barrett's description of the skull of Y. huangi more useful. Be aware that this paper is entirely a description of the skull and not a biomechanical analysis of the skull.

Popular Without Movies

Yunnanosaurus is an early dinosaur with no movie credits in its accomplishments. There is a WizScience video that exists regarding Yunnanosaurus. Unfortunately the other videos mentioning the dinosaur either do not actually show the animal or have a very abbreviated (think 2 - 5 seconds) of actual mention in the videos. This is a short video, but one can add on this how to draw video as well to get more Yunnanosaurus today:

Long Lists of Knowledge

Yunnanosaurus is a well known sauropodomorph and as such has many fact pages devoted to it hosted online. These include well known sources such as KidsDinos and Prehistoric Wildlife. It also includes sources we have not referenced often including Age of Dinosaurs and a Raresource page. For the first time in a very long time we can also share a coloring sheet of Yunnanosaurus (that may actually be almost accurate). Enjoy reading facts and coloring your own Yunnanosaurus this evening!

Silly Sauropodomorphs of Space

This is the last week of November and therefore it is the week of the calendar creature. This month that animal is the sauropodomorph Yunnanosaurus. Discovered originally in the southwestern Chinese province of Yunnan and described in 1942 by C. C. Young (the anglicized name of Chinese paleontologist Yang Zhongjian). The original fossil material consisted of twenty incomplete skeletons of the facultatively bipedal sauropodomorph dinosaur. Two species are recognized: Y. huangi Young 1942, and Y. youngi Lu, et al. 2007. The teeth of Yunnanosaurus may be the dinosaur's most interesting feature, as we shall see later in the week; however, its position early in dinosaur evolution is also interesting and we may learn a lot about early dinosaur environments from studying this animal over the week.

Quality Images

The best quality images of Shastasaurus are all somewhat similar and lack the flash that is often added into dinosaur illustrations. However, there are a number of high-quality illustrations of Shastasaurus that are interesting and intriguing. One such illustration shows Shastasaurus digging along the bottom of the ocean for its food, presumably. This is one of the only (if not the only) image of this ichthyosaur from a more ventral angle. The belly of the beast, figuratively and literally, is not all that impressive. The flippers and underside of the trunk are smooth and non-remarkable; however, the tail is differently interesting (that does sound odd, admittedly). The tail vertebrae, assuming that this illustration is entirely accurate, occupy the ventral region of the tail and curve downward to the end of the hypocercal tail. The tail also has what appears to be an untethered membrane which, being untethered to the body or the remainder of the tail, would need to be extremely rigid in order to produce any appreciable thrust. Either way, adding the membrane to the tail is not unique to this illustration, but this version of the animal has probably the most conservative amount of interpreted soft tissue that has been shown.

©Nikolay Zverkov

Ancient Marine Books

Shastasaurus has been featured in a number of books concerning and written about marine reptiles of the Mesozoic. As noted earlier in the week Shastasaurus appears in a limited number of tribute videos as well. A number of popular articles have come and gone, particularly in recent years, pertaining to the diet of Shastasaurus. These articles mention specifically the hypothesis that the toothless snout of Shastasaurus was ideally suited to suction feeding and ingesting cephalopods specifically. However, the mandible and jaw joints of Shastasaurus were not adapted to accommodate the range of motion required for successful suction feeding. Shastasaurus most likely required massive numbers of cephalopods with or without the ability to suction feed given its size. One of the key abilities of Shastasaurus in ingesting massive numbers of animals like this would be to get into a position to be able to eat them. Its large size and hypocercal tail probably made Shastasaurus basically incapable of high speed swimming. However, migrations of smaller taxa or simply larger, slower swimming taxa, may have been on the menu for this large mostly lumbering predator of the Triassic. Clearly it must have been successful at one time or another or it would not have survived long enough to make it into the fossil record. Conversely, Shastasaurus may have swam slowly through large groups of fish, or circled them like large whales sometimes do today to funnel them into an area fit for gulping.

This is highly speculative and not entirely taken from any of the sources discussed on Tuesday; take this conversation on diet with a grain of salt, that is to say. Hypothetical situations are fun to discuss, but definitely be aware that there are scientists that make a living studying Shastasaurus that know more about its diet and the evidence for and against specific hypotheses that have been discussed here today.

©Nikolay Zverko

Behold the Mountain

I have referenced mountains a number of times when discussing Shastasaurus this week and that is not without purpose. Shastasaurus was, after all, named for Mount Shasta in California. Shasta is an active volcano in the Cascade Range and is absolutely enormous. The ichthyosaur is as well. Many large marine animals comparable to Shastasaurus are of similar morphology. The most notable character of this morphology is actually the lack of a character: the dorsal fin often shown in recreations of later ichthyosaurs is entirely lacking in Shastasaurus. Other morphological characters of Shastasaurus are expected, such as a hypocercal vertical tail and pelvic and pectoral fins. The skull of Shastasaurus is not completely known, and as such the cranial form is not entirely known either. Therefore the only characters we can discuss for certain are the tail and dorsal fin and the breadth of the ribcage of Shastasaurus. The ribcage is short and shallow, giving Shastasaurus a slender body profile. The toothless snout (mentioned before), slender profile, basal tail, and lack of dorsal fin show Shastasaurus to be a basic and primitive ichthyosaur. The size of the animal is interesting, however, as it is enormous and exceptionally long (up to 21 meters estimated) despite its shallow ribcage (approximately 2 meters deep by 7 meters long) and primitive features.

A Day of Papers

Shastasaurus is a complex animal and because of the complexities associated with this giant marine reptile there have been a lot of different studies, descriptions, and research delving into the life, anatomy, and phylogeny of Shastasaurus. There are key papers that are more important than others, as is usually the case, that possess more information critical to better understanding of extinct taxa. In this case there are two papers describing potential (and debatable) species of Shastasaurus. These two species are from New Mexico and British Columbia respectively. New Mexico's species, S. altispinus is from the Upper Triassic and was described in 1989. The species from British Columbia, S. neoscapularis, was touted as the exemplar of the genus in 1994. However, since that time the five-plus species have been reassigned, redescribed, and only one sure species now exists (plus two still debated species: S. liangae of China and S. sikanniensis once known as Shonisaurus). A discussion of the implications of S. liangae's short snout and its placement in Shastasaurus was published in 2011. The only quality description of S. sikanniensis was penned under the name Shonisaurus sikanniensis; the animal was reassigned in the previous article about S. liangae and its short snout.

Monday Videos

As promised, here are the videos for Shastasaurus. These are tribute videos, however, they are here for your perusal and viewing pleasure.

Facts and Swimming Mountains

A full size Shastasaurus would be a sight to behold in today's waters. Appearing very piscine (fish-like if you prefer) with its vertically oriented tail but entirely lacking dorsal and anal fins. Approximately the size of a modern blue whale, this marine reptile has managed to capture a fascinated, though small, audience in its considerable wake. The fact that a lot of people know about this animal make it somewhat popular online. This popularity leads to more than a few websites hosting facts about the giant marine reptile such as About, a new-to-us site called Dinosaur Facts, and Prehistoric Wildlife. I plan to save the tribute videos for tomorrow, and there are quite a few of them to share, which means tomorrow will have a lot of images and videos.

Mountainous Ichthyosaur

Shastasaurus pacificus is the only certain species of the genus of mid Triassic ichthyosaurs. The middle Triassic is early in ichthyosaur evolution and Shastasaurus is clearly not as advanced as the more well known Cretaceous ichthyosaurs. However, the Triassic was a pivotal time for these early ichthyosaurs that led to the later Cretaceous ichthyosaurs and Shastasaurus was major player in the evolution of this family. Lacking a dorsal fin and more slender than many later members of its family, Shastasaurus possessed a significantly different shape than the later and more familiar marine lizards.

©Dmitry Bogdanov

Drawing in the Bat

Having a lack of popular references there was no reason to talk about them yesterday. Instead, we come back today to look one of the only well illustrated restorations of this prehistoric bat. The majority of illustrations refer to modern bats to illustrate their interpretations of these older bats. Only one set of illustrations appears to draw its inspiration directly from the skull. The shape of the illustrated heads are what gives away this inspiration of course, with the properly drawn animals possessing a more elongate head than modern bats; the poorly drawn Icaronycteris pieces have a shortened bat face with large flat noses. The ears of either version are open to even more interpretation, but it appears that almost all of these have been illustrated as typical bat ears. This makes sense, though, given that Icaronycteris is hypothesized to have been capable of echolocation. The tail, however, is longer than the legs in the fossil and all of the interpretations.

Your Average Sized Bat

Measuring in at approximately 14 cm (5.5 in) long from nose to tail Icaronycteris was just a little larger than the Little Brown Bat (Myotis lucifugus), the most common bat in North America. The wingspan of Icaronycteris 37 cm (15 in) is one and a half times the span of M. lucifugus. However impressive that sounds, we have to realize that Icaronycteris is still a rather small animal and most likely weighed around what M. lucifugus does (up to 14 grams) and that makes it a relatively small mammal, and a small bat specifically.

Paper Thin Fossil

The American Museum of Natural History holds records for the two most definitive articles written on Icaronycteris. The first article, Simmons and Geisler 1998, describes the familial relationships of the bat, its history, and basically every behavioral and ontogenetic piece of information that has been suggested, tested, and hypothesized about Icaronycteris and Eocene bat populations in general. This tome of information draws from all previous works on the bat and new hypotheses, phylogenetic character descriptions, and their results as interpreted by Simmons and Geisler. An earlier paper that is referenced by the first paper and is also prominent in describing this bat is Novacek's 1987 paper on the auditory capabilities of Eocene bats including Icaronycteris. This paper is shorter, but describes the hearing functionality of what may have been some of the first echolocating flying mammals; adaptations that highly influenced how and why bats behave the way they behave as we know them.

The Single Video

Whenever we have a little known animal we have few if any videos. Icaronycteris is one of those animals that has very few videos associated with it. The videos that do exist are patchy, but there is a link that calls itself a video of an animation and reconstruction of Icaronycteris. However, it calls the fossil bat a "3D Dinosaur" which we know is not at all accurate and is in fact only a stock photo. The lies of the internet sadly. Instead of looking at the non-videos, we should take today to appreciate the fossil itself. The fossil reveals a typical, as we currently think of them today, bat-like mammal. We cannot see the teeth in this view, but we will see later how they are very much like the bats we know today. As stated previously, this bat, despite being very early in the bat lineage, is already very "modern" in terms of its bat-like morphology. The fingers and the teeth are the most outgroup features of Icaronycteris as the teeth are more like those of a shrew and the fingers retain more primitive claws on the first digit. Most notable about the fossil, the tail is longer than those found in modern bats. This is rather evident in the fossil. What is not evident, unfortunately, is the wing pattern of these old bats. We can see later what this membrane may have looked like, but for now we have only the bones themselves.

©Erik Terdal

Short Facts

The fact files for Icaronycteris are lacking almost entirely. The only page hosting a fact file for this fossil bat is About. Eocene mammals are not unpopular really, but fossil bats are very rarely discussed outside of scientific conferences and research discussions. Hopefully after this week that trend will begin to change and more links for fossil bats and more information about them will begin to show up online; That is not the end goal of course but spreading more facts about this small fossil bat would not at all be a bad thing.

True Bat Wings

After a little contemplation it was decided that we should continue our discussion on bat wings, but instead of continuing with small maniraptoran dinosaurs we are going to look at the origin of the phrase bat-like. We described the wings of Yi qi as bat-like and many pterosaurs are described in the same way. However, the origin of the descriptor comes from the small flying mammals that people were most comfortable with (or uncomfortable with). One of the earliest complete bat fossils belongs to an animal known as Icaronycteris. The small microchiropteran, a group of small bats dependent on echolocation, dates from the Eocene and contains three recognized species: Icaronycteris index Jepsen 1966, Icaronycteris menui Russell et al.1973, and Icaronycteris sigei Smith et al. 2007. The type species was originally recovered from the Green River Formation and constitutes the most completely described specimen of the genus. Clearly already a "fully functional" bat, one of the earliest bats was already well adapted for the kind of life that bats still adhere to today.

©Andrew Savedra, Royal Ontario Museum specimen

A Cheeky Image

The images shown this week are all serious reconstructions of the small maniraptoran dinosaur Yi qi. Those reconstructions are all as scientifically accurate as possible with the scientists and artists working together. The majority of the illustrations show the dinosaur in stark high definition with feathering finely illustrated and the sharpness of the image finely tuned for the most realistic habitats possible. John Conway went down a slightly different path in his illustration. This image uses soft colors and a lack of sharpness that captures the dinosaur perfectly while leaving enough of the detail muted that we can interpret some of the fine details for ourselves. Additionally, Conway made his version a little more frumpy looking and a little less angry, as Yi qi tends to look in most other reconstructions.

©John Conway

You Can't Buy Popularity

Yi qi is a popular little dinosaur for a variety of reasons, though that popularity is not entirely evident outside the paleontological community. The announcement of the description was met with typical news outlet fervor, but it died quickly, perhaps even faster than many other new dinosaur announcements. Part of the excitement of the dinosaur is actually the debate that it has caused because of its unique wing structure and the uncertainty of the morphology of that wing. Being toted as a "bat-winged" helped the dinosaur to become a news item and granted it some of the popularity that it has experienced. Its popularity also made many more of its clade members more visible to the public. The name Scansoriopterygidae is still difficult to say but it is more well known now because of Yi qi.

©Matt Martyniuk

What About the Wings

There is something about the forelimbs of Yi qi that seems unnatural or even a bit downright creepy. Yi qi had feathers preserved with its skeleton. Those feathers are stiff and cover almost the entirety of the body. However, there are no flight feathers associated with this dinosaur. Instead, the elongate digits (Digit III being the longest digit) are spanned by a preserved membrane that lacks avian-like feathering altogether. Evidence for this membrane stretching to the torso is not preserved in the fossil, though it has been interpreted as extending that far medially in order to complete a wing structure. The inclusion of a styliform bone, debated as misidentified radius and ulna by some (David Peters for example), was proposed to have expanded the wing caudally from the wrist and past the range of the digits. This gliding wing would have been substantial with this addition but obviously becomes somewhat smaller and less expansive without the added distance from the wrist.

From Xu et al. 2015

Election Dinosaur

Take a moment away from the election in the United States to read this paper describing Yi qi the Jurassic maniraptoran dinosaur. It will make for a pleasing distraction, regardless of who you support, to simply ignore the anxiety and just read some science.

Video-less

Yi qi is very new. Because the little maniraptoran dinosaur is very new it has not had many chances to appear in documentaries or anywhere else. The dinosaur made a few popular news stories and even the short video that we shared yesterday from the publisher of the original description, Nature. There are other short videos, such as this video posted by The Paleo Archive, an account that discusses fossil animals of all kinds on YouTube. Those interested in the take of a young child (seeing young dinosaur fans at work is always fun) can watch this video by Rogie the Dino Boy. His interpretation of the facts associated with this dinosaur are fresh and delivered in the way that only a child could deliver them.

Facts and Coloring Sheets

The video collection WizScience produced a video showing and discussing Yi qi, which is as good a place to start as any in looking for facts. There are other videos to consider as well, such as Nature's short documentary on Yi and its hypothetical flight abilities as described by scientists up to and including research conducted in 2015.

The video from Nature is a companion to the 2015 paper that finally described the 2007 discovery.  The fact files are ultimately all the same as that shown by About, with a little bit of variation speckled throughout the different fact files. The facts are analyzed by a lot of different authors and the interpretations are varied depending on the way that the authors see the data and interpret the reconstructions. Darren Naish, for example, describes the "Dino-dragon" in a different way than it is typically depicted. In the realm of coloring sheets, two black and white drawings could be used for coloring. However, the drawings belong to their artists and are not available for my inclusion here. Therefore, here is a link to different versions of the interpretation of the dinosaur; one by Jaime Headden and the other by Sergio Perez.

Bat-like Theropods

The very small theropod dinosaur Yi qi had unique fingers that separated it from all other theropods along with its sister scansoriopteygids, which were climbing and gliding arboreal maniraptorans of the Jurassic of Asia. A partial skeleton of the animal was described in 2007 and, as of now, remains the only skeletal remains that have been recovered or described of the small dinosaur. Yi qi, like its sister taxa, is assumed to have lived in the trees rather than merely climbing them and gliding down from them. The most unique aspect of the reconstruction of Yi qi is the bat-like patagium that was stretched between the fingers of the dinosaur. We can read the paper later that describes this, but for now, enjoy this Emily Willoughby reconstruction based off of the description:

©Emily Willoughby

Typical Illustrations

The illustrations of hadrosaurs have changed as much and as often as any other subset of dinosaurs over the years since their initial discoveries. Hadrosaurs, however, have arguably changed less than other dinosaurs. The reason for that is not a lack of hadrosaur research or knowledge but rather the general shape of hadrosaurs. Postural changes of the dinosaurs and enhanced precision of soft tissue depictions of the head and neck are the most profound advances in hadrosaur illustration. Beyond these categories, the bodies of hadrosaurs in particular, the depiction of hadrosaurs has remained fairly uniform because there was not a whole lot to change in those areas to begin with. Parasaurolophus and its contemporaries were depicted with bovine bodies because they were basically the cows of the Cretaceous. This explains the bovine appearance of hadrosaurs between the neck and tail quite readily. One other thing that changed in illustrations of Parasaurolophus and other dinosaurs overall that has made a significant impact on the illustrations we see today is the organization of the toes and posture of the feet. Older illustrations feature elphantine feet that end in columns for sauropods and hadrosaurs are not treated much differently in this respect. Some depictions of Parasaurolophus are a little extreme in their depiction of the bovine state of the dinosaurs, such as this image by John Conway (though he is far from the only artist depicting these dinosaurs in this manner).

Parasaurolophus with hypothetical frill attached ©Tom Parker

The Best Paleo Video Ever

The 1980's and early 1990's were filled with some amazing paleontology movies and documentaries. These included images of newly discovered dinosaurs and an immense multitude of hadrosaur models, animations, and recreations. Chief among these is Parasaurolophus and the intriguing anatomy that it possessed. The original attempts at recreating the sounds of Parasaurolophus and many other hadrosaurs were undertaken by a large and varied number of scientists, but the one I remember best was a clip of David Weishampel blowing on plastic piping to create deep resonant sounds. Since that time there have been many other recreations of the sounds using computers and complex algorithms to hit precise notes, such as in this compiled sound clip attributed to Sandia National Laboratories and the New Mexico Museum of Natural History (https://www.youtube.com/watch?v=lBU6zfI1b0U):

These same practices are used to create the Parasaurolophus sounds in popular documentaries such as Dinosaur Discoveries. Did this dinosaur really sound like this? We may never know, but there is a strong amount of evidence that says that Parasaurolophus may have potentially sounded like a living low frequency producing machine. It was probably not capable of defending itself with sound, but that would make for an interesting defense if it was possible.

Parasaurolophus Makes A Good Read

©Brynn Metheney

There are specimens of Parasaurolophus from all over the western half of the continent. There are remains from Utah, New Mexico, and Alberta, Canada as well. Many of the remains of the dinosaur come from Canada, in fact. There are remains described on a regular basis from Dinosaur Provincial Park. A wide variety of topics are discussed as well. These range from ontogeny and heterochrony (life history and developmental change in time and events) in Parasaurolophus to acoustics of the nasal passage, as mentioned yesterday. Parasaurolophus may not have made it into space (contra this Brynn Metheney drawing) but it has indeed created a stellar impression on the history of life and the careers of many biologists and paleontologists.

Astronaut Hadrosaur

©Lisa Andres

The October dinosaur of the month was Parasaurolophus. This week counts as the last week of the month but we have missed two days, so October's monthly dinosaur will have a somewhat shortened spotlight. That works out just fine considering that we have discussed Parasaurolophus once in the past; check the Facebook page for the week of October 29, 2010. It is an interesting convenience that Parasaurolophus is kind of having a six year anniversary this week. As many dinosaur enthusiasts know, Parasaurolophus is an interesting hadrosaurid dinosaur. The crest of this dinosaur has been used to estimate many things about hadrosaur crests, including its noise making ability and the potential for endothermy via warming turbinates within the nasal passage. Possibly the most recognized of all the hadrosaurs, Parasaurolophus is one of the dinosaurs that most readily and entirely embodies the phrase "charismatic megafauna" and we will see why and how in the next few days, or at the very least be reminded of that in the near future.

Undergrad Adventures

Our undergraduate researcher, a junior (3rd year) did a phenomenal job with her poster this evening. She presented it to a lot of prominent researchers and really held her ground when prodded for more information about her methods and interpretations of her results. She would be a great researcher if she continued on in science (she wants to be a veterinarian, for now at least) and any of us would be pleased to continue working with her in the lab or as a colleague elsewhere.

Hybridizing Post

The museum here (Natural History Museum of Utah) is fantastic. I recommend starting at the top and slowly meandering down the ramps. The geological areas are filled with interesting displays as are the straight up biology areas with cells and DNA and wildlife dioramas. The real gem of the museum, as would be expected, is the fossil area. Rather than explain all of the mountings piecemeal, I ca offer a bit of a photo tour of that area and join this post with the post for my photography. I am almost sad to say that my phone makes a competent camera, but I think the differences between my real camera and my phone should be somewhat evident.