Support PBS!

I endorse supporting PBS fully. Unfortunately they do not stream one of the neatest dinosaur shows they have put together in the past twenty years that is dedicated to a single taxon. I guess that is why we can be grateful for YouTube content. In lieu of placing a lot of links in here today, I recommend watching this NOVA special on Microraptor. There is a lot of good information and some good CG dinosaurs running about. Most importantly, it gives one a lot to think about concerning Microraptor, which can lead to some fun conversations.

Feathered and Fun

From Hone DWE, Tischlinger H, Xu X, Zhang F (2010)

 The feathers of Microraptor are not even remotely questionable. They are clearly viewed attached to all four limbs. The tail possesses well defined feathers out at the caudal-most end of the tail as well. The only real question with that much feathering is how closely related is Microraptor to extant birds? The paper from which today's image is ripped examined the feathers with UV light to conclude that they were real and attached directly to the skeleton. It did not delve into the depths of the dino-bird question, but the evidence for Microraptor as a linking taxon is outlined in other papers. As a small dromaeosaur we know that it belongs to the family of dinosaurs most closely related to birds. We can also infer an ability to glide for short periods and distances or at least fall with grace thanks to those long feathers on the limbs.

Reference:
Hone DWE, Tischlinger H, Xu X, Zhang F (2010) The Extent of the Preserved Feathers on the Four-Winged Dinosaur Microraptor gui under Ultraviolet Light. PLoS ONE 5(2) e9223.

Week Off, Week On

We are back. After much traveling a week off seemed best as I had already missed much of the week. There should be a good dinosaur for this week back. An interesting dinosaur. A small dinosaur! Not quite a bird, but almost a bird, we shall discuss a dromaeosaur. Considering it is a small dromaeosaur, the name Microraptor is a very accurate description of the dinosaur. We have discussed small dromaeosaurs before, but this takes the lack of height to a whole new level. In fact, Microraptor gui is small enough that it could easily perch on a human arm, much like an extant bird of prey that is trained to do so. I kind of want one for that purpose alone. Look at how adorable yet fearsome it is.

©Durbed, Some rights reserved. This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License

Popular Everywhere

I have had plastic Stegosaurus toys since I knew there were dinosaur toys. I have a number now. I also have a Stegosaurus shaped pillow that roars. It is a generic roar, but a roar nonetheless. Some of the most popular venues for Stegosaurus have been the Jurassic Park series (the novel featured a sick Stegosaurus, not Triceratops), the Walking with... series, and the non-descript little plastic dinosaurs that one can purchase anywhere in the world. Other iterations of Stegosaurus have made their ways into popular books, television shows, and other imagery, but the Stegosaurus in my mind will always be tied to those plastic toys in some aspect. The DinoRiders Stegosaurus is a pretty iconic dinosaur also, right up there with Snarl from Transformers (which apparently later becomes a cat of some kind?). Regardless, the fame of Stegosaurus translates into many appearances, a wide audience, and some nifty kid's books.

Iterations of Spikes

Stegosaurus has gone through many iterations of posture and general body shape. The plates of Stegosaurus have been the subject of just as many interpretations as the entire of body the animal. These have ranged from tall triangular plates to flattened roof-like plates (from whence the name Stegosaurus, "roof lizard" comes). These shapes are all based on the different fossil plates that have been recovered. They are mostly the same shapes of course, but morphological differences and soft tissue on the plates may have altered how the living animal looked significantly. The differences can be seen in the many different illustrations below.

Middle "roofed" plates illustration by Giovanni Caselli. Other illustrations are unknown.

Special References

Old publications or new publications; either general topic will allow you to retrieve hundreds of writings concerning Stegosaurus. Dinosaurs that are as popular in video formats as Stegosaurus was yesterday tend to have a lot of printed material devoted to them as well and this genus is, of course, not an exception as it has hundreds, maybe even thousands, of papers and books that focus on or dedicate some text to Stegosaurus. One of the better old books was written by CW Gilmore in 1914 and discusses all of the "armored Dinosauria" that was at the time in the Smithsonian (United States National Museum). Throughout the 20th Century Stegosaurus was revisited time and again, especially after the discovery of non-North American members of its family. All of the literature that exists is far too much to read. I picked out some interesting reads instead. These should be fun, some may be a bit older and therefore out of date, but fun anyway:

Heat loss through convection

Growth of plates

Stegosaurus plate vasculature

Histology of Stegosaurus plates

Movie Dinosaurs

Stegosaurus is a simple dinosaur to find movies for. The real problem is actually weeding out the poor quality movies and terrible interpretations of Stegosaurus. We can highlight the best Stegosaurus movies and let the readers decide which are their favorites for the day:

Walking with Dinosaurs: https://www.youtube.com/watch?v=eUdcrYvhJr8

Walking with Dinosaurs' stage show: http://www.dinosaurlive.com/dinosaurs/stegosaurus/

I'm A Dinosaur's Stegosaurus: https://www.youtube.com/watch?v=pvTvrvDolTk

The Land Before Time's Spike: https://www.youtube.com/watch?v=2t2iFLshgWQ

Green Rabbit's singing Stegosaurus: https://www.youtube.com/watch?v=iBzsCcu0IEQ

The Lost World: http://jurassicpark.wikia.com/wiki/File:The_Lost_World_Jurassic_Park_-_finding_Sarah

Stegosaurus the Mighty

There are tomes dedicated to Stegosaurus. Actual tomes of knowledge and popular culture artifacts, drawings, and videos. Stegosaurus has always been a popular dinosaur, partly because of its rather interesting skeletal anatomy if for no other reason. Regardless, it presents very interesting links from a wide variety of sources. These include strictly educational sites like the New Zealand hosted Science Kids and the less professional, but just as educational, Kids Dig Dinos. There are, due to its popularity, also PBS videos and a lot of coloring pages. Simply searching for Stegosaurus brings up far more links than I could possibly discuss in one day. It is a scary amount of information, I promise.

Comparisons of Then and Now

The interpretations of Stegosaurus over the years have changed, as they have with all kinds of dinosaurs. Originally, the iconic stegosaurs of yesteryears were small headed tail dragging plate bearing arches with stubby little legs. As with many other dinosaurs the original interpretations were also swamping dwelling monsters with little intelligence and slow ponderous gait. The reality of dinosaurs, we know now, was rather different, and Stegosaurus was more than likely no different. Since the older interpretations fell out of favor the limbs have become more erected and the tail, hips, and back have changed their orientations sufficiently to change the entire look of the dinosaur dramatically. No longer do stegosaurs appear to be shuffling lizards of the swamps, but a believably active and high energy herbivore has come to exist in the minds of dinosaur enthusiasts and casual dinosaur recognizers alike. Most people may not draw the connection between stegosaurs of then and now, but they can tell you, without any knowledge of Stegosaurus that the newer illustrations look far more dynamic and energetic. They certainly look as though they would be able to swing that tail with much more vigor and probably chase down an intruder or conspecific territory encroacher, assuming they were ever territorial.

Alarm System

There is, in our posts, a stunning lack of an amazingly iconic dinosaur. I searched all the posts and somehow missed one of the most iconic dinosaurs of the American West. If I have not missed it and we are repeating a week, that is also okay because I will definitely find new materials. It will be new information to everyone regardless. Therefore, for this week, we will go over the fantastic dinosaur Stegosaurus. Be prepared. Be happy. Be patient with Stegosaurus if we have repeated this information.

Finally Back

I am finally back at the computer. Just to round off Segnosaurus though. There are a large number of popular outlets that claim Segnosaurus including books, animatronic and static displays, and video games. These are all interpretations of the dinosaur, of course, so they should be appreciated for their interpretative qualities and interesting manifestations. Also, in video game environments, for instance, there should be a recognition that the models are often hand-crafted by gamers, and therefore have no budget behind them. Far too many people complain about the accuracy of detail in video game models, I probably have in the past as well, but it is not worth the time or effort to do so honestly. The model used for Dinosaur King, as an example, is budgeted and therefore rather "acceptable" by most standards, even if it is an updated Therizinosaurus.

Late Days

I am updating from my phone, the computer has been busy or giving me trouble the past few days, but it's okay. The important thing is that we all recognize the fossil material of Segnosaurus and what that material looks like. As with many fossils, not all of the animal was ever discovered. Enough was that we know what Segnosaurus looked like with reasonable accuracy. We know, for instance, that this dinosaur was a therizinosaur and therefore has many corresponding characteristics of that group of animals. These include the forelimb and hindlimb morphology as well as that of the crania that exist. Unfortunately these animals are not often displayed, but when they are they are often modeled after not only their fossils, but those known from other members of the family; that is nothing new in paleontology though!

Short List of Papers

Here is a short list of papers that should be read to gather more information on Segnosaurus and other therizinosaurs. I do not feel that I need to give a synopsis of each paper here:
A review of therizinosaur diet
Introducing Segnosaurus (introduces the family, but discusses the genotype)
A new therizinosaur order?
A "newly" discovered hindlimb of Segnosaurus

Drawing and Strangeness

I always enjoy a sped up drawing. This video is no exception as it is quite nicely drawn. These sped up images are always fun to watch and enjoy. There is also this video which appears to show a therizinosaur said to be Segnosaurus fighting a Tyrannosaurus after eating a juvenile. We have stated that therizinosaurs are typically herbivores, but there is some wiggle room in the knowledge and practice of the diet of Segnosaurus. Unless you like Linkin Park I would suggest muting the video. If anyone knows the origin and can shed some insight in that way, it would be much appreciated.

Segnosaurus Was A Mom Too

While everyone in America is celebrating Mother's Day, or has at least acknowledged it hopefully, it is important to remember that Segnosaurus had to have had its share of mothers as well. It is kind of necessary for the species to continue after all. The kids version of the Encyclopedia Brittanica online has an entry dedicated to Segnosaurus. It is rather short and there are better websites out there, including the Dino Directory at NHM London and Enchanted Learning. The drawing is good for coloring. So enjoy coloring with your mother, or kids, today!

Size and Strangeness

Therizinosaurs are known for their large claws, in part. Therefore, it is a little sad that this slightly older interpretation of the dinosaur has very small claws on its forelimbs. The claws on the hindlimbs were always depicted as slightly smaller, therefore the claws on the hindlimbs being depicted small here are not a surprise. The herbivorous diet of the animal is depicted here in the beak-like appearance of the face. In fact, it looks almost entirely hadrosaurian in its overall shape and make up. Segnosaurus is not, most likely, this much of an herbivore in its appearance. It probably did not have cheeks either way. The fact that it was as tall as it appears to be in relation to this one armed business woman is not that amazing as therizinosaurs were at least medium sized theropods. The general shape of the illustration is appropriate, though, which means that the dinosaur is actually quite appropriately drawn, despite the inaccuracies.

Say No Saurus!

Michael B.H.

No one wants to be called slow. The fact that there is a dinosaur that belongs to a genus called the "slow lizard" is a little sad, perhaps even a little pitiful. However, the dinosaur of the week probably was a little bit slow, and it was certainly one of the stranger dinosaurs that existed out there in the world. Those rather strange dinosaurs are collectively known as therizinosaurs and have been widely regarded for a long time as the oddest theropods for a variety of reasons, including that they are the only theropods that are widely considered to be entirely herbivorous. Segnosaurus galbinensis is another Mongolian find of the 1970's that was returned to the West through the Soviet Union expeditions of the era. Four specimens were eventually discovered, though these constitute less than 50% of the skeleton. Despite this, we know that the therizinosaurs, and Segnosaurus, had stocky limbs, which led to the naming of the genus. Slow, stocky, and bulky, Segnosaurus is a very odd dinosaur.

Street Cred for A Whale

Ambulocetus has drawn a lot of attention since its discovery from all sides of the evolution debate, fossil lovers, whale fanatics, and mammal enthusiasts. It is not hard to see why it would be so popular, given that it is an interesting fossil animal regardless of the exact nature of its placement in the history of life, let alone whales. The animal is so important in that history of mammals that it has shown up in a few documentaries, including The Walking Whale from National Geographic. There are mentions in books, plush toys, plastic toys, and more. The influence of the early whale is enormous, kind of like whales. The reverse side of the science of the whale, the use of the fossil by Creationists and Intelligent Design folks, is also prevalent online (and probably offline but I cannot attest to that). There are sites dedicated to that area of the whale's popularity and they are easy to find online. I choose not to link them directly as they are so easy to find. Instead, enjoy the fun things associated with the whale (and the fossil and its history of course), like this fantastic family reunion portrayed by the multitalented Ursula Vernon:

More of Ursula Vernon's work is available here

How to Amble

Ambulocetus in the natural history museum in Pisa, Italy

Locomotion is an interesting topic, and one that a lot of people really love to study. I do not study locomotion all that much, but I cannot say that I am not very interested in how things get from point A to point B. The ways in which Ambulocetus did this are somewhat varied, as we would expect. Walking on land the animal was most likely a little slow and cumbersome, but able to walk with enough grace that it was still adapted enough to walk on terra firma. The swimming portion of its life was probably a little more tail-powered, but it also appears that some may think that it doggy-paddled a little bit to help itself move. Popular images, however, always use the tail locomotion story when describing Ambulocetus. This innovative way to move around the waterways, it can be argued, was the initial use of such methods prior to the advent of the actual whale's tail and true whale locomotion.

Paper Pile of Whale-like Proportions

Delighting once again in the popularity of an animal, we have many many papers at our disposal. Whales, as previously mentioned, are charismatic megafauna and due to the fragmentary nature of many fossils have come under fire and reveled in the delight of the masses, often at the same time. We therefore have piles of literature for and against the evolutionary implications of Ambulocetus as well as whales in general. The key papers for today, however, are those concerned specifically with the biomechanics and the origin of Ambulocetus and other whales. Time is of great import in all paleontological studies, and the pinpointing of the origin of whales is an interesting discussion to enter into. Since there are now a variety of whale-line fossils, pinpointing the exact species or genus that should be considered the first true whale is an interesting, and potentially impossible, diagnosis at the present time. This has not stopped anyone, and the discovery of fossils in India have been used to make arguments dating whales to approximately 54 mya. Perhaps of more interest to most people are the biomechanical implications of Ambulocetus locomotion. This topic is covered in a number of papers, but an investigation into the artiodactyl relationship of whales and the description of more holotypes and what they reveal biomechanically caught my eye above all others. The description paper is nice to read, but the video yesterday basically did the description for us, so enjoy these papers and feel free to find others. I have another few to potentially mention tomorrow.

Whale or Propaganda Baby?

Propaganda has a long history. Whales have a long history. Whales that walk are propaganda, if you watch the right videos and listen to the right arguments. I do not, and will not, get into that. Everyone can have their own views on the fossils and what they mean, and they can all fight amongst themselves. Additionally, I will not tolerate any kind of arguing one way or another. Civil debate is one thing, argument is another. As it is movie Monday I could try to be fair and show videos from each side, or I could simply refer everyone to a fun documentary that could create arguments. It could, but it will not around here. Keep yourselves civil, that is all I want. Now, enjoy this interview with Dr. Hans Thewissen:

Walking Whales

There are a lot of good places to share facts today. There are a variety of reasons for that, but of course the most obvious is that whales are charismatic megafauna and the history of evolution of charismatic animals is big business in science. That and it is simply really awesome to see the transition of animals when we have a good serial fossil history. Remember, though, that a good serial history does not mean that we have every single step on the way to whale. Anyhow, Prehistoric Wildlife and Dinosaur Jungle both have good fact sheets and are not our usual fare; we are branching out today. Additionally, AMNH has a nice short news release about some display work they were doing with Ambulocetus and there is a really nice progression animation to go with an exhibition that the Museum of New Zealand had in the past. It is well worth the minute or so that it runs.

Furred Fur a Change

© Kelly Taylor

Typically, for some unknown reason, Ambulocetus is illustrated as a slick creature. However, as a mammal that has not quite yet dedicated its life completely to living in the water, it is hard to think that these creatures would have been entirely devoid of hair. They may have been less furry than this pair seen here, but they must have had some sort of hair. Regardless, fish was most likely on the menu as it appears to have been here. The whiskers I could actually see being relevant to the swamp life that has been hypothesized for Ambulocetus. In the dark silty waters of a swamp, the feeling powers of the whiskers would have been very beneficial for a large predator like Ambulocetus. It would also be very much like the apparatus seen in otters, muskrat, and beavers, as well as other river/pond/swamp dwelling mammals.

Ambling Toward the Waters

© Nobu Tamura

It has become apparent that I somehow have never discuss whale evolution of the most primitive kind. After searching all of the posts here I noticed that there were none concerning what is often considered the most primitive amphibious step towards cetaceans: Ambulocetus natans. One of the transitional fossils that shows a bridge between land mammals and the ocean-going Cetacea, Ambulocetus was an amphibious shoreline or swamp dweller that was equally at home on land and in the water, but not truly a master of either. As their descendants became more attuned to the water, they would leave the land, but these fossils truly show adaptations to both the land and the water. It is thought that Ambulocetus may have hunted like crocodiles, ambushing prey from below in the water, or by staying extremely still on land. Unlike crocodiles, swimming was effected by use of apparently webbed fore and hind limbs.

From Awful Interpretations...

Totally awful interpretation of "natives" (Maori) hunting Moa.

Moa are enormous birds. They have, as enormous birds, captured the imagination of countless numbers of people over the ages. No doubt the Maori, despite hunting them to extinction, were in awe of the giant steaks running about on the new islands they colonized. The popular culture impact of Moas has not been as great as that of the so-called Terror Birds, but the general populous has probably heard of Moas if not seen images of them. It has not hit the toy market as hard as most popular culture darlings, but it has hit gaming markets, which is close to the same thing. Moas are also popular book topics. Either way, they are big birds that had big personalities and often become big members of the popular culture buzz. However, we only have a few of these popular culture items at our disposal right now.