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.