Megaraptor Introduces Itself

There are a lot of fact pages about the genus Megaraptor but most of those fact pages are far less entertaining than the I'm a Dinosaur cartoon series. The cartoon for this dinosaur is not very informative so we do have to share fact pages as well but all is far from lost. The pages hosted by About and Enchanted Learning suffice to augment the cartoon. They may be slightly less entertaining to most children but they are good reading for this occasion.

Recent News

Recently in the news there has been talk of a new "Megaraptor". That animal has not been described as belonging to the genus Megaraptor but to better understand what exactly that news is describing, we really do need to understand the genus to which it is being compared. Megaraptor is a genus of large dromaeosaur-like theropod belonging to a larger group of dinosaurs that includes the Gondwanan coelurosaurs and allosaur-like theropods. Its original description as a Southern Hemisphere dromaeosaur has since been retracted and reoriented a number of times and at some point during the week we will try to describe the phylogeny of this strange dinosaur.

Christopher Chavez

Old Art

Osborn's drawing and hypotheses about the habits of Apatosaurus are timeless classics of thoughts about dinosaurs at his time.The tail dragging sauropod of that time is long gone in both literature and illustration but the images stay with us, as does the idea that the dinosaur was a lumbering beast incapable of supporting its own weight out of water. These images will slowly disappear from the popular psyche as older cartoons and illustrations as they become more obscure; however, they were once the height of scientific thinking and some aspects of the reconstruction of dinosaurs from then can still be seen in today's modern depictions of dinosaurs.

Illustration and text by Henry Fairfield Osborn

Apatosaurus Thunders into the Spotlight

Apatosaurus appears in too many documentaries, texts, and movies to mention in a single post. There are already posts that address some of the older popular posts that are on the internet or in print. Some of the best new material has to do with the splitting of Brontosaurus from Apatosaurus that was so popular a short while ago. Additionally, the studies on supersonic tails in sauropods, Apatosaurus in particular, have been extremely popular in the past six months. There are videos that address this hypothesis and the subsequent testing of that hypothesis. One of the best sites that was not shared prior to this writing is the DK Eyewitness introduction to Apatosaurus. Their Apatosaurus model is very Diplodocus looking, but the information is still quite intriguing and the presentation is very much inline with the typical presentation of dinosaurs in popular outlets.

Deception of Lizards

Juvenile, Sam Noble Oklahoma Museum of Natural History. Photo by Matt Wedel

Our imaginations and everything we know bout dinosaurs has always told us that dinosaurs are enormous beasts.We know that Apatosaurus is one of the largest dinosaurs that traversed North America. However, it was also small at some point in its life. Small is subjective of course and we learn early on that we cannot always say something as simple as "it's large" or "that is small" when we are trying to describe or identify an animal or object in isolation. We keep saying that Apatosaurus is enormous, but we have yet to compare it to anything. For the sake of perspective, Apatosaurus is 22.8 m or 75 ft long. In comparing terms that means that Apatosaurus is approximately 1.5 school buses long. The juvenile shown above is significantly smaller, as we can tell by comparing it to the adult leg in the background. There are many specimens of Apatosaurus in museums, on display, and in ready-to-be-quarried quarries across the western regions of North America. These specimens are in various levels of completion, but because there are many that are significantly complete we have a very good idea of how large the animals were at different stages of life. That is why we can put adults and juveniles together, call them what they are, and not split them into different species.

New Papers

The sheer number of papers written about Apatosaurus rivals the dinosaur in size. We can venture as far back as Marsh and up to the present. The past few years have seen a revival of sorts in the amount of research being conducted and published on the giant sauropod. There are reports of new remains of Apatosaurus from Utah. There are numerous discussions and debates over the cortical areas of bone, the tails (both in regards to their centers and their development), and the necks of Apatosaurus as well. The number of papers could keep anyone busy for an entire day.  Hopefully everyone will find these papers enjoyable and learn something new about Apatosaurus.

Size Gets Views

Popularity has been gauged a number of ways on this blog but the number one reason for popularity of any dinosaur usually comes down to its size. We have had a few middle of the road taxa that are not popular because of their size, but this is generally an exception to the idea that size, when it comes to dinosaurs, truly matters. Some dinosaurs make it into movies and documentaries because they are small and others because they are larger than anything else we can imagine. Apatosaurus fits into the second category: being enormous. The immense size and popularity of this dinosaur has led to its inclusion in countless documentaries and movies. The entire dinosaur is not always treated equally, however. The tail of Apatosaurus has reached enough popularity as a research project that at times it has outshone the rest of the dinosaur. Most recently Apatosaurus has been famously killed onscreen in Jurassic World. There are many videos showing the behind the scenes making of the dinosaurs, a movie that does still employ physical models in an age where dinosaurs of that immense size are often portrayed in only digital means. Anyone that was taking note of the dinosaurs in the park may have noticed that Apatosaurus took the reigns of giant sauropod from Brachiosaurus for the first time in the movies. The latest popular news about sauropods (reconstituting Brontosaurus as a separate species from Apatosaurus) may have led to this new sauropod king of the Jurassic series. Regardless, the sadness of the scenes in which Apatosaurus appears in Jurassic World is awful; however, its inclusion in the movie with another prominent sauropods says a great deal about its current popularity on the silver screen.

Apatosaurus Favors Children

There are a ton of posts on this blog already written about Apatosaurus and none of them appear to match our current version of fact sharing posts. Rather than search through them all and attempt to rehash the kid friendly links in this post feel free to comb through the past links. One link that did not exist the last time that  Apatosaurus was discussed here was the popular, on this blog, video series I'm A Dinosaur. There is now a video for Apatosaurus and it is, as they all are, fun to watch:

Cover Animal

The animal for the month on the calendar will feature this week as this is the last full week of July. That dinosaur happens to be one of the largest on the calendar as well and it is also one of the dinosaurs that we have focused on multiple times here. There is almost never enough in one week, so discussing one animal three times is not actually a problem as it allows us to felve even deeper into the knowledge about this specific dinosaur. The dinosaur astronaut of the week is a whale of a dinosaur: Apatosaurus ajax.

©Brynn Metheney

One More Feathered Fossil

If Protoavis was a bird or if it was a small theropod this re-creation is an acceptable representation of what the fossil may have looked like fleshed out and alive. The caption mentions specifically that the feathering is inferred and that the feather pattern is based on the feathers of Archaeopteryx. The head is scaly and extremely dinosaurian. The eyes, in the orientation that they are shown here, appear to have some binocular capabilities; this overlap of visual fields was mentioned by Chatterjee in The Rise of Birds. This particular illustration is possibly one of the better life restorations of Protoavis that has been shown this week. This is in part because it does not entirely commit to either interpretation while allowing for both sides of the argument to show through in this illustration.

Popular Fragments

Protoavis has never fully ascended to the popularity of an animal that was whole or to the kind of animal that Protoavis really had the potential to be. Lacking the solid evidence that proves that the fossil is or is not a chimeric group of fossils, we can never be entirely sure of the nature of Protoavis. If it is a very early bird it pushes back the origin of birds into another age (the Triassic) and makes birds even more ancient than previously thought. If it is a theropod, but not a bird, then Protoavis is a bipedal dinosaur well on its way to the building blocks of bird origins despite not being a bird. The alternative, that it is a group of fossils, makes the remaining material of little use and uninformative. Whatever one decides, there is a lot of literature that needs to be examined in order to make an informed decision.

Skeletal Remains

There are many assertions made from as many angles about the remains of Protoavis from the fossil's head to its toes and tail. Starting at the skull, it is described as complete by Chatterjee, though the known fossil is recognized to be missing much of the rostral aspect forward of the temporal region. Additionally, Chatterjee made many observations of the quadrate and its mobility. Subsequent observations and descriptions by Paul, Chatterjee, Ostrom, and others have not validated the shape, articulation, or mobility of the quadrate within the specimens of Protoavis that have been described. The braincase is similarly marred by disagreement. Disagreements are made with the cervical vertebrae and some of the other post-cranial elements, but none as much as the quill knobs that Chatterjee mentions on the broken ulna of the type specimen. The inclusion of these supposed quill knobs caused an inference of feathering and that is why current illustrations depict Protoavis as being a small feathered dinosaur. Many subsequent descriptions of the same anatomy have concluded that the material, because it is fragmentary, cannot be confidently described as possessing quill knobs and flight feathers. Whether this is truly the case or not we may not know for a very long time, if ever, but the image of a feathered Protoavis is normal whereas a non-feathered Protoavis is not common and may not even exist.

Paperless Protoavis

The original description of Protoavis is not online. There are mentions of Protoavis in many different places including a short review of bird evolution by Luis Chiappe. This review mentions the first 85 million years of bird evolution; we know that there is far more to the bird evolution story than just 85 million years. The bird is also mentioned many times in Sankar Chatterjee's The Rise of Birds. Chatterjee mentions Protoavis multiple times, probably because he did the original description. However, he does mention it in relative situations and for good reason. Appropriate mention of your own described taxon is tasteful and worth appreciating.

Mixed Up Fossil Movie

All of the arguments and contentious debate around Protoavis should have stirred up so many videos and documented debates that there should be absolutely no gaps in the video record of the debate around Protoavis. However, there are many gaps and a lot of the discussions and arguments that have been presented are actually only available in print and very little has been recorded regarding the attributes and diverse descriptions of those attributes as they are seen in the fossils. Also lacking are discussions about the nature of the fossil itself; i.e. there are not videos concerning the idea that the fossils are actually an amalgam of multiple animals from a "death assemblage" deposit. There is a WizScience recording that we can share here though. The video shares some facts and the discussion of confusion caused by the fragmentary fossil as discussed on Wikipedia (not much new information is shared here).

Facts About A Potential Dino-Bird

Despite the contentious nature of the Protoavis fossil there are multiple websites dedicated to presenting facts about this odd fossil. Most of the sites directly address the controversy. Dinosaur Facts is one such site that addresses the controversy and offers an opinion. That site is more direct in its opinion than About, which mentions that there is controversy but does not take a side or voice a strong opinion either way. There are also sites that barely mention or may entirely ignore the controversial fossil material like Dinosaur Jungle. If the controversy itself is high on your list of interests, EvoWiki has a page dedicated to just the evidence from both sides of the argument.

Before the Birds

Protoavis texensis was named and described by Sankar Chatterjee in 1991. The fragmentary remains appear extremely avian but retain many theropod characteristics and the mysterious mixture of characteristics has led to the contentious and problematic diagnosis and descriptions of the small dinosaur since the initial description. Aspects of the anatomy have been described and redescribed a number of times and interpreted as different anatomical structures by different authors. There have been discussions of the fossil representing a massive death assemblage rather than a single specimen. However, bird, early bird, lots of remains, or single theropod, Protoavis is a dinosaurian
fossil regardless. That dinosaur is small at 35 cm tall and rather old at approximately 210 million years.

Drawing A Bird

©Kelly Lance

When you have teeth or pseudoteeth soft prey are almost always on the menu. Typically, as we mentioned earlier this week, Pelagornis is shown eating fish or simply soaring above the waves. In fact, fish catching pictures are even rather rare with this bird. However, Pelagornis eating a squid is a novel illustration. Remember, the bird is enormous and the squid, therefore, is also extremely large, though not a giant squid still by any means. Grasping the squid like this Pelagornis would be able to easily keep a squirming slippery cephalopod in its beak while re-positioning the catch while trying to swallow the animal.

Making It in Video Games

The most popular culture savvy reference for Pelagornis, other than from the Smithsonian Channel, is from ARK. The game has brought many fossil animals into the spotlight in recent times. The information file is, as it has been for many extinct animals, posted online with commentary and narration.

Additionally, there is a very nice video from James Gurney that shows and describes his process in illustrating the bird for Scientific American and the oil board version called Giants of the Sky. His process is intricate and detailed and it produces fantastic artwork.

Carolina Monster

Grabbing fish on the wing was once the niche of needle toothed pterosaurs and is currently the realm of petrels, pelicans, and a few other ocean-going birds. The time between pterosaurs and modern birds is littered with the psuedotoothed birds of various forms that we have not yet discovered. The Charleston Museum houses one of the largest birds that ever lived and certainly the largest pseudotoothed bird that ever took flight. Looking at the skeleton without anything for scale, the size of the bird is still quite appreciable. The head is enormous at approximately 16 in (40 cm) long but is still dwarfed by the wingspan of the bird. That wingspan is equal to approximately 20 ft (6 m), which is the same as the once common Harrier Jump Jet. Imagine a bird, as we know them, but the size of a medium sized two person jet fighter. That is a truly immense bird.

Giant Bony-toothed Birds

In the past decade the giant bird Pelagornis has been studied more often than in the previous century. Three new species have been named in eight years and the two most prominent papers on the internet are from the past three years. One of those papers, Fitzgerald et al. 2012, describes a set of remains from Australia that constitutes the first group of remains of Pelagornis discovered in Australia. More recently there have been studies conducted on the growth of  the characteristic pseudoteeth of Pelagornis. The structure of the pseudoteeth are described in detail. That structure is rather intriguing and makes for a very interesting read.

News and Aerodynamics

Computer voiced descriptions of the giant bird Pelagornis rule the day on the movie Monday. However, the Smithsonian Channel has a well put together video on the aerodynamics of Pelagornis on YouTube. Today we will let the Smithsonian, and more importantly Daniel Ksepka, do the talking:

Facts About Giant Birds

Pelagornis is a little known bird for unknown reasons. As the largest bird genus that has ever graced the airs of the Earth the birds in this genus should probably be a lot more famous than they are right now. There are a number of websites that share images and facts about the genus out there though, meaning that the popularity of the fossil may be below the radar of most popular sites, but there is some knowledge and a following out there. The sites that mention Pelagornis are some of the most common websites that we see on a regular basis on this site. This includes About, as it usually does. Kidzsearch, the online kids encyclopedia shared here sometimes, also has a very short discussion on Pelagornis. The Latin Times also gets in on discussing this group of birds. The birds have been discovered at diverse sites across the entire globe (The type specimens include: P. miocaenus from France, P. mauretanicus from Morocco, P. chilensis from Chile, and P. sandersi from North Carolina), which is why there are diverse sources like The Latin Times.

Ignore the Placement

The problems with bird fossils exted far beyond the crushed and fragmentary remains that they are composed of. This fragmentary nature leads to many hypotheses of relationships and uncertain positions within the group. This includes the recently announced material related to ostriches and the fact that the tree, based on genetics, morphology, or whatever else, is in continual flux these days. That being said, we can approach our fossil for this week knowing that we are going to mention the family and genus without going into too much detail on hypothesized positions in the group. Regardless, the largest of bird genera needs very little more than itself to be intriguing enough to discuss. Having pseudoteeth also makes this giant fossil rather intriguing. Described in 1857 by Lartet, the genus Pelagornis consists of four currently recognized species; P. miocaenus Lartet, 1857, P. mauretanicus Mourer-Chauviré and Geraads, 2008, P. chilensis Mayr and Rubilar, 2010 and P. sandersi Ksepka, 2014. All four species have pseudoteeth and the wingspan of P. chilensis is estimated to be the second largest of the four at 17 feet from wingtip to wingtip. Compare this the albatross (and an eagle and  pigeon), one of the largest extant seabirds, above. The species P. sandersi is estimated to have had a wingspan at least seven feet longer (that is 24 feet folks). We can compare that to even more extant birds, because it is amazing.

Feather Your Dinosaur

There are many interpretations of Compsognathus rolling around the internet that still appear quite dinosaurian. That is to say that many of the illustrations that are on the internet are still showing tight skinned Compsognathus running around in very dinosaur-like situations and doing dinosaur-like things. However, Alexander Lovegrove and many other newer artists or artists that change their styles to match current trends in science have adopted a much more feathered look for Compsognathus. This look is very interesting for Compsognathus and seems to be quite fitting. This small family of dinosaurs wears its feathered jaguar spots quite well. The gape on what appears to be the adult is impressive, though not unrealistic at all and, for a little dinosaur, is certainly more than enough to capture small lizards, mammals, and insects. Aren't they adorable?

©Alexander Lovegrove

Popular Dinosaurs

Compsognathus is a popular dinosaur. The well preserved fossils that allow us to know so much of its anatomy also allow us to portray the dinosaur in a variety of modes including animation and as static models. These, in turn, create an even more popular image of the dinosaur. The dinosaur has been used as a model for Jurassic Park and a number of other movies and documentaries. It is the quintessential small dinosaur that can be shown with a very dinosaur-like body plan (Coelophysis not withstanding).The dinosaur has also appeared in books, popular magazines, and as toys. Most recently it has been given a role in the developing game ARK. They appear to be capable of being tamed and running around with your character. There have been less useful sidekicks.

Compsognathus' Extra Material

Nopsca 1903

The name Compsognathus means "elegant jaw" with an alternative definition of "dainty" but the dinosaur was far from fragile; though it may have been elegant. Both specimens are robustly preserved, the German specimen even more so. The German specimen is thought to contain eggs in addition to its integument preservation. A chicken sized dinosaur with well preserved skin and eggs a marvel unto itself but could certainly spawn chicken-dinosaur-egg jokes. This specimen also contains gastric contents, illuminating the diet of the small dinosaur as it was in the instant that it died. Illustrations of Compsognathus prior to the more famed illustration by Nopsca in 1903 that shows these coincidental fossils, such as that by Marsh in 1896, were recreated in the traditional dinosaur pose with the tail dragging along behind it. Both Nopsca and Marsh's illustrations are great for what they are. Marsh's illustration shows the body plan and skeleton of the dinosaur in a reasonably accurate portrayal of the bony anatomy, though not in posture, as noted earlier. Nopsca's illustration is great for showing the coincidental fossil material. Together they show a great deal of information about the dinosaur.

Marsh 1896

New Papers

Previously Compsognathus papers were discussed on this blog at the following link. Since that time other research discussing or using Compsognathus as a model taxon have been published. This is great for us because we are staying current and updating what we previously learned about our tiny dinosaur friends. These newly published studies include dinosaur reproduction (ovarian follicles and a debate about their existence). Dinosaur reproduction is always a hot topic and therefore an interesting and entertaining topic. Additionally, there are mentions of Compsognathus in new books written about the origin of birds. The mention is small but important as the discussion about the origin of birds is important information to get out to more and more people (there are many that still do not recognize that birds are dinosaurs). These comparisons are steeped in comparative descriptions of dinosaurs and birds that were published previously. To close out paper Tuesday I direct you to the Cambridge Journal Robotica. If one is not able to view the PDF on the Cambridge site, an alternate but older version of the material is available from Transactions of The Japan Society of Mechanical Engineers. This may not be as current, however, it does include images of the robot in use:

©Akama et al. 2011