STL Science Center

STL Science Center

30 June 2015

Confounding Arguments

Just prior to the release of Jurassic Park as a movie, but after its publication as a novel, there was a renewed interest in Procompsognathus. Whether this arose from the book and movie or simply because the fossil was looked at with new eyes, two papers reviewed the material that was attributed to the holotype and one nearly declassified the animal. That paper, a 1992 study published in the Journal of Vertebrate Paleontology, was written by Paul Sereno and Rupert Wild. Their findings declared that Procompsognathus was in fact a fossil chimera composed of theropod post cranial skeleton and crocodylomorph cranial elements (and a forelimb for good measure). Other papers since that time, see Fabien Knoll, have asserted that parts of the postcranial skeleton are not portions of Procompsognathus and this should not be a surprise anyway. The holotype is based on a three part slab fossil which could have easily been "contaminated" with other species. There is no insinuation in any papers that the chimera was purposefully assembled, but evidence supporting non-Procompsognathus material in the fossil is important to spread apart from the material that does belong to the dinosaur. To that end, in 1993, Sankar Chatterjee, after more fossil preparation work, set about refuting Sereno and Wild's 1992 paper (the abstract for this work can be found here). Chatterjee asserted that the skull was not that of a crocodylomorph, but of a basal theropod. It appears that all sources since those two have agreed that Procompsognathus is, as the 1990 version of The Dinosauria states, "a problematic theropod". That version of the publication actually considered Procompsognathus a nomen dubium based on confounding and insufficient evidence. The agreement on the general basal position of the skull has been further agreed upon, I think we can say this satisfactorily, as being close to Coelophysis and Segisaurus halli in the tree. Paul's 2010 Princeton Field Guide states that Procompsognathus is a misleading name as the dinosaur is not related to Compsognathus very closely at all; so much for the comparisons in body shape presented here the past few days! However, we can still use those comparisons as both genera and Coelophysis (to which we know Procompsognathus is related) have basic small theropod body plans and would have had similarities in diet and sometimes in locomotion, though the typical unknowns (e.g. behaviors and mannerisms affecting locomotion and life history) must still be observed as unknown whenever discussing dinosaurs.
Model is ©Steve Baldock, photo posted by Amos Wolfe

29 June 2015

Lacking in Movies

Procompsognathus never made the casting calls for any of the Jurassic Park movies. Their cousins Compsognathus did, however. Because of this, we have a visually similar dinosaur on the big screen. Assuming that their behaviors were somewhat similar, because of their size and similar body plans, Compsognathus could be a reasonable stand in for Procompsognathus in terms of watching how they may have behaved.Procompsognathus is estimated to have been about the same size from nose to tail and at the shoulder, but Compsognathus is estimated to have had more mass overall. The increased mass only amounts to about 3 lbs., but that could be enough to dramatically alter how it ran, hunted, and ate. Somewhat ignoring those differences, take a look at the puppets that were used in The Lost World to represent Compsognathus and consider them as similar in movement abilities to Procompsognathus:

28 June 2015

Simple Links, Simple Dinosaurs

Procompsognathus is a small dinosaur. Small enough that it would make a great pet, minus the voracious appetite and untamed nature, and would probably entertain many children and adults. Probably not to that end, but facilitating the idea that Procompsognathus was a small and child friendly animal, there are many links for the dinosaur that are accessible to all and full of information. There are information only links like the one for the Natural History Museum of London and there are links that show information and have coloring sheets associated with them like that for Enchanted Learning. The people at Kids Dinos have put up a good information page as well. Unfortunately coloring sheets outside of that found on Enchanted Learning are not in good supply.

27 June 2015

Gracile Dinosaurs

©Richard Andersson
The forgotten eaters of John Hammond, Procompsognathus, are well remembered by readers and dinosaur enthusiasts in general. It is not because this small dinosaur had any remarkable anatomy that was extremely odd or beautiful. In fact, Procompsognathus was one of the most basic of theropods. It looked like a theropod and it ran about like a theropod. The dinosaur was a small version of its later descendants and cousins but with a weak jaw, in comparison to later theropods, and grasping fingers. It is likely that Procompsognathus was able to jump, like Compsognathus, Coelophysis, and the small lizards running under the feet of the growing ranks of dinosaurs. The ability to jump coupled with speed and grasping fingers could have possibly been an indication of a diet of insects as well as other small meat items, like lizards and small mammals. The idea that it may have been venomous is, as far as we can be concerned at the moment, is fictional. That could always be a possibility of course, but there is no way to say with certainty at the moment.

26 June 2015

Not A Crocodile

In 1993 the movie Jurassic Park was in theaters and the stars were being unveiled. Michael Crichton had created a star-studded cast for his novel and that left the movie with a great list of characters to choose from. Not all of the dinosaurs could make the cut, of course, and some were eventually replaced or left out entirely. One of those characters that was ignored and omitted was the small dinosaur Procomsognathus ("Before the elegant jaw" referring to its pre- Compsognathus time frame of existence). Living in the earliest Triassic, Proconpsognathus triassicus was a very small dinosaur and was used, by Crichton, to inflict the death of John Hammond in the original novel. This scene was played out by Compsognathus in the second movie, The Lost World, when they ganged up on and subdued the dinosaur hunter Dieter Stark. During this year the position of Procompsognathus as a non-crocodilian was also affirmed and the dinosaur was solidified as a coelophysid theropod. Considering the genus was 80 years old at the time, such a strange revelation may seem out of place, but the gracile little animal was difficult to place due to the fragmentary nature of the fossil, as you can see below.
Holotype on display in Staatliches Museum für Naturkunde Stuttgart

25 June 2015

Beloved Toothless Wings

As many know, Pteranodon means "toothless wing" and, as we can see from the fossils, the beak is most definitely without teeth. That has little to do with the fact that so many people love Pteranodon. It is popular enough to have been a main character/creature of the novel and to have featured somewhere on screen in each movie; those mentions may just be as symbols or words, but not every genus has been in every movie. Regardless of its presence in the park, Pteranodon has made its mark in every other dinosaur market, including video games (the unforgettable divebombing in the Sega Genesis game immediately comes to mind), and kids books, documentaries, television, and even popular movies. The real problem with all of this popularity is that the general public, it appears, still does not understand these animals at all. In the post-Jurassic World releases the media, almost as a whole and including reviewers that claim to be dinosaur enthusiasts are still calling Pteranodon and all other pterosaurs birds and dinosaurs interchangeably. It becomes, rather quickly, a nerd-rant, but the fact that this basic premise of pterosaur/Pteranodon biology has been lost on journalists is frustrating and confusing at the same time. Everyone ought to take a moment today to explain to someone that Pteranodon is not a bird or a dinosaur. It will be worth it, and it will make for a happy Pteranodon. Far happier than this one:

24 June 2015

That Winged Finger

Pteranodon is a pterosaur, and like the other most famous member of the (smaller) pterosaurs, Pterodactylus, it had a wing that was held open by a single elongated digit. That digit allowed for a wing that was approximately 5.6 metres (18 ft) in males and 3.8 metres (12 ft) in females. These dimensions allowed for enormous surface areas and, despite their large reptilian bodies, were more than enough to keep aloft the extremely light Pteranodon. That may seem like a confusion of terms, but the large reptilian bodies of Pteranodon were composed of light skeletal elements, similar to those of bats and birds in their general composition and pneumatic properties, though definitely different enough that three should never be confused if presented in isolation. Even the elongate crests on the backs of Pteranodon skulls are pneumatic and lightweight, allowing the flying reptile to move its head about while in flight without changing its center of mass significantly. Debate has ebbed and flowed about the purpose of the crest beyond sexual dimorphism and has included ideas such as rudder control during flight. This would be an interesting and not unrealistic use of the crest, but I cannot claim to know its morphology well enough to present either side of the argument with an assertive conviction. Personally, I think the wings were soaring devices and would to imagine that they crest was used to impress the ladies and to aid in steep banking turns, but more proof of that concept is certainly in need. Unfortunately, due to their lightweight skeletons Pteranodon tend to be preserved in slabs of very flat stature and with little to no soft tissue imprints aside from the wings.

23 June 2015

The Papers of A Prolific Writer

Pteranodon has been studied by a large number of people over the years. In last 30 years, about, the literature surrounding Pteranodon has been reviewed and the majority of the remains also have been reviewed and redescribed by a single individual. Nestled in the heart of North America, where a good majority of the specimens from the Western Interior Seaway have been found and stored, a huge amount of literature has been generated by Chris Bennett. Pteranodon is not the only animal that he has written about, but off and on for the past few decades Dr. Bennett has written some highly praised, circulated, and criticized (as all paleontologists have) articles on the animal. He has not broached all subjects related to pterosaurs such as biomechanics, for instance, but is gracious enough to host the majority of his articles online. These include ontogeny, functional morphology, and osteology, amongst other topics. There is also work on sexual dimorphism in his catalog. Aerodynamics have been discussed by Bramwell and later by Bower. If taxonomy is more the object of interest, there are papers on that as well by Miller, for example. There are papers everywhere waiting to be read, and most of these are older, and can therefore be found free more easily.

22 June 2015

Pteranodon Videos

From I'm A Dinosaur to Primeval, Pteranodon features heavily in the film industry in various genres. The reason for this is actually quite straightforward: Pteranodon is a mysterious reptilian creature with absolutely no morphological homologues in the living world. There are a number of reptiles that have cranial ornamentations somewhat similar to Pteranodon, but really only in that they are crests of bone and soft tissue of one variety or another that are vaguely similar in appearance. Pteranodon is also a major player in documentaries, like those shown in the Walking With Series, and in movies, like the ones that populate Jurassic Park, Jurassic World, and the test islands of the other movies. These depictions are not, of course, always accurate in regards to the biomechanics of the animals, even when they are accurate representations of the flying animals themselves. Their flying abilities and physical looks, unfortunately, often cause them to be called flying dinosaurs by the media and this can lead to confusion. Sadly, we have to deal with this lack of knowledge on a semi-regular basis, especially when a new blockbuster movie comes out.
Yes, I like Jurassic Park III, and this is a reference. Blame Sam Neill if you must; Alan Grant is great.

21 June 2015

Father Pteranodon

Pterosaurs are well loved by all ages and groups. That, as it tends to do, lends itself to wonderful amounts of links and coloring sheets and all kinds of educational resource. The most obvious, at the moment, is definitely Dinosaur Train. The show is based on a family of Pteranodon. Visiting your local PBS website, or not so local if you are from outside of the U.S., will furnish you with more than enough educational links to discuss with your family today. Coloring sheets abound as well on sites like Enchanted Learning. The most important thing on this rainy (here) Father's Day (also here) is that everyone learns and people get to enjoy their days and their families.

20 June 2015

Heinrich's Pterosaur

©Heinrich Harder
Some times the classics are almost correct and do not need a great deal of revamping. Beautiful as the newest illustrations of Pteranodon appear some times, the original depictions of Heinrich Harder are actually quite spot on for the presently accepted morphologies of Pteranodon. The wings, for instance, are fairly appropriate, though debates probably still range over the placement of the patagium between the legs and tail. The small head crest would most likely indicate that these individuals, if they are Pteranodon longiceps, females. The larger head crests would indicate males, as Pteranodon longiceps is considered to be sexually dimorphic with males having larger bodies overall, including the crests on the head. Not seeing different body sizes in these animals we can only make an educated guess based on that shorter crest. Harder, however, may have been illustrating these Pteranodon based only on the fragmentary evidence of the fossils that had and have been collected throughout the American West.

19 June 2015

Another Omission

©Matt Matyniuk
Somehow, through a calculated decision at the time I discussed flying reptiles three years ago, I omitted Pteranodon. Due to the focus on getting correct information out on Jurassic World dinosaurs and other creatures, we really need to talk about that ubiquitous flying reptile and king of the skies. Probably the most prominent member of the genus is Pteranodon longiceps Marsh 1876 which was originally recovered in the western Kansas Smoky Hill Chalk deposits that were laid down during the existence of the Western Interior Seaway. Pterosaurs in general have long been associated with water because their best preservation has been associated with shorelines or the middles of what was once ocean and Pteranodon is not an exception.

18 June 2015

Swimming with Class

Teylers Museum, Haarlem
Mosasaurus has, as expected, had a big draw as a fossil, on the blog, and in the movies. This is very apparent in Jurassic World, of course, but other documentaries and such that are almost movie length would count as well. The video game presence is also noteworthy, as is the literature (non-scientific) in which one or another species of Mosasaurus is discussed or pictured. These are, to be certain, most usually lumped together under the generic name, but it makes little matter in the long run. The point of knowing that these animals are known in children's literature, popular literature, and other venues like video games, is understanding that they are charismatic enough that they are considered worthy of study as well as awe inspiring and fantastic by many including the general public. Scientists kind of have to have interest from someone or their research grinds to a halt rather quickly, unfortunately. That sort of interest has led to the massive displays of mosasaur remains in museums worldwide, like that of the type specimen in Haarlem and others. They are wonderful to look upon also, so they are worth seeking out.

17 June 2015

Reptiles in the Ocean

The ocean going reptiles of the Mesozoic were not a small faction of the population of those oceans at that time. Since different groups were considered the ruling reptiles of the ocean at different times it can be safely assumed that the various groups of pelagic reptiles were the apex predators of their day. The families that held those titles became increasing larger to usurp the title from previous groups but, because of the needs of aquatic locomotion, did not appear to be strangely exaggerated in shape or form (think of the reactions of most people the first time they see the arms of Tyrannosaurus or Carnotaurus). From ichthyosaurs to plesiosaurs there was not an enormous swing in terms of what family was considered the apex predator group, though both had higher members in specific niches. Mosasaurs, on the other hand, evolved forms that were capable of being not only the apex predators in a wide variety of niches, but also dominated the previous acme of icthyosaur and plesiosaur domination. In fact, they ate quite a few of the largest ichthyosaurs and plesiosaurs. There were copious reasons for this changing of the guard.

1. The teeth of Mosasaurus species were conical and bone crushing. Some members of the family ate hard shelled organisms with very different teeth, but Mosasaurus species were purveyors of the larger, squishier, bodies of the ocean and preferred to crack down only on the shells of ammonites and sea turtles when looking for crunchy food items. These were, of course, much softer than giant clams, though a case could be made for the toughness of ammonite shells as extremely hard bodied. Either way, the conical teeth of mosasaurs were excellent in their presumably strong jaws at breaking into the softer shelled swimming organisms and certainly the soft bodies of plesiosaurs and whatever remaining ichthyosaurs that were in the oceans of the Cretaceous.

2. Swimming with paddles worked for the somewhat slower plesiosaurs; smaller necked plesiosaurs tended to be speedsters while their longer necked cousins took a more relaxed approach at life. Mosasaurus species, however, were built for speed all over. Their streamlined crocodile-esque shape is not a coincidence. That shape of body has been toyed with in many lines including mosasaurs and crocodiles and has proven effective for speed and maneuverability in aquatic landscapes. The evolution of paddles to stabilize and turn the body and a very powerful tail capable of motoring at high speed make for a deadly combination for slower animals and the ability to ambush, assuming mosasaurs followed the typical marine camouflage patterns of predators, would make them deadly for swifter prey as well, though with a lower success rate probably.

©Nobu Tamura
There are other obvious, and less obvious reasons for their domination of the oceans, but these two are highly visible to all and rather obvious to infer, therefore lending themselves to quick observations. I know there are a lot of people that can add to these reasons, and their input is definitely welcome in the comments!

16 June 2015

All There is to Know

Anyone looking for a one stop paper on anatomy of Mosasaurus can visit this JSTOR page and take the rest of the day off. The paper is thorough and well written, and covers a wide swath of the anatomy of Mosasaurus hoffmannii, making it an indispensable reference for the mosasaur enthusiast. There are also descriptions of fossils throughout the history of our discoveries of mosasaur specimens including Mosasaurus beaugei Arambourg, 1952 and Mosasaurus conodon Cope 1881 (admittedly the second paper is more of a review of the taxon). Technically minded individuals may appreciate studies of dental microstructure in mosasaurs or maybe even rare earth element analysis  that determines where and when an animal was alive. The last paper reminds me of the summer I did inorganic chemistry research. I enjoyed some parts of that more than others.

15 June 2015

Manic Mosasaur Monday

I got a little sidetracked last night and forgot to hit enter on the post. Here is the post for Monday though.

The majority of Mosasaurus videos on the internet right now are steeped in so much Jurassic World glitter and shininess that the reptile has lost a lot of his educational links in the muddling. There are plenty out there though. The reason for all of the pre-JW links is as obvious as the reptile: it is definitely one definition of charismatic megafauna in the fossil record. We are discussing a large aquatic reptile, a world often forgotten in the dinosaur craziness of the Mesozoic that, when it does surface, is thanks to more news about enormous ferocious predators more likely than not. However, the pre-JW links of Mosasaurus related material were not all educational and news stories themselves. There was an episode of the BBC show Primeval (the translation makes it a little more disturbing) which has a very unlikely attack; humans are not worth an animal that large beaching itself I am quite sure. There are more than enough documentaries also, from the sensational Discovery series Mega Beasts (we can cut them some slack because they did reach out to people that know their mosasaurs) to the serial killer portrayal in the Reign of the Dinosaurs series (also Discovery, a bit overly dramatic).

14 June 2015

Kids at the Pool

First of all, regardless of the feelings anyone may have for or against the latest movie, this t-shirt design related to the movie is fantastic:
Best design I have seen this weekend, for anything, bar none. Anyhow, there are links everywhere for Mosasaurus. Enchanted Learning has some information and fun about Mosasaurus and even Dinosaur Train has a lot of videos and information about Mosasaurus. The state of North Dakota is behind Mosasaurus entirely, endorsing it and disseminating an awful lot of information to the masses about this very popular fossil from their state. There is plenty to read about in these few links, but if there needs to be more, the links abound just typing Mosasaurus into Google.

13 June 2015

No Single Image

Today I think it would be wildly inappropriate to post a single image of a single species of Mosasaurus. There are a lot of different interpretations of Mosasaurus and these can vary depending on the species that one is looking at as well. Fortunately, there is a nearly catch-all place to look at Western Interior Seaway Mosasaurus species in illustrated form. The work of the late Dan Varner has been collected by Mike Everhart and hosted on his site for a long time, and Varner focused a great deal on the animals found in North America, but that list is extensive in its own right and is not necessarily speciated from those species found in Europe and Asia. In a few images he placed some unique and interesting traits like forked tongues, but they are peculiar enough in their speculation (and phylogenetic relationships) that they actually do not appear absurd. In working on marine reptiles in the not so distant past I frequently saw these images, and I have grown quite fond of them. I encourage everyone to take the time to explore and appreciate them.

12 June 2015

The Attraction of Dinosaurs

Now that Jurassic World is out in theaters, we really should stop and ask ourselves, what is it that the public finds so endearing about dinosaurs? The size of dinosaurs is a clear option, as most people enjoy the site of animals that are far larger than seems practical for life. Elephants and whales are clear examples of this type of animal. Dinosaurs are even bigger (the ones people love the most anyway), maybe making that one of the most important factors that there is in determining our love of dinosaurs. I think it is more important for the second more obvious idea that governs our love of dinosaurs to exist. That idea is that we love dinosaurs not because of their sizes, but because they are mysterious animals that we see in snippets of time. Those short time captures are usually death events, but occasionally the death event itself is so rapid it actually turns out to be a portrait of the life history of the dinosaur. These are invaluable to us as the fossils in the death throes, maybe even more important. When we are truly lucky those life portraits are not only well preserved nesting dinosaurs or fighting dinosaurs, but they can even end up being mummified to the point that their soft tissues are still present in some form of quality.

In respect to one of the major players of the movie, one of the larger fossil animal genera, and a member of the "ruling reptiles of the sea", we shall discuss the mighty Mosasaurus this week. Oddly enough, Mosasaurus has not made it onto the list here yet, though other members of its family certainly have. Currently six species are recognized in the genus with Mosasaurus hoffmannii Mantell 1829 residing in the slot of type material. The genus has been around slightly longer and was assigned originally by Conybeare in 1822 with his description of the "Meuse River lizard". Despite the name, which is location based, the aquatic reptiles were ocean loving animals, and their size was appropriate for large predators of the Mesozoic oceans.

11 June 2015

Teeth of Rhabdodon

Teeth in question
The fluted teeth that give the dinosaur Rhabdodon its name are hard to find a good image of online. There are photos and images in the papers about the dinosaur, but these are not readily available without some screen captures and cropping. The teeth and the body of the dinosaur are actually kind of strange in their hypsilophodontid-esque morphology. Despite these morphological similarities the phylogenetic positioning of Rhabdodon still remains solidly in the iguanodontid family. Regardless, the fluted tooth name refers to the shape of the tooth.

10 June 2015

Cretaceous Bovine Anatomy

Rhabdodon and other members of the Iguanodon family have rather basic and schematic anatomy. One iguanodontid looks quite a bit like the next member of the family and so on down the line, for the most part. That is, of course, an ugly blanket statement when anatomy and morphology are considered. Rhabdodon was a smaller member of the tree and, as such, the anatomy of the animal was much like that of its larger cousins, but scaled down a bit. The lack of soft tissues makes it difficult to determine if any of the missing organ systems were different or if they were, like the skeleton, a slightly different but mostly scaled down version of its cousins.

09 June 2015

In French, s'il vous plaît...

The first responses to my search for papers are in French. That is not a problem in and of itself, unless you know absolutely zero French. The fact that there are French language papers published in regards to the material discovered in France and potentially attributed to a species of Rhabdodon (remember some French material was questionably assigned to a third species) is perfectly logical. The paper on Spanish remains is not in Spanish though, so it makes one wonder if the French authors are just being selfish in their publishing (that is just a joke, you know!). Some of the most intriguing information can be found in the paper about the braincase of Rhabdodon, if you like papers about the head and brain.

08 June 2015

Rhabdodon on the Move

I have shared the Dinosaur Planet episode Pod's Travels about five times now because it has a lot of different insular species that we have discussed. I even shared it once on an Iguanodon post because Rhabdodon is, in effect, an insular version of Iguanodon. I can share it again in here and will do so. The animals are referred to simply as Iguanodon but the show notes mention that they are based on skeletons of Rhabdodon. I have never personally understood why television does that sort of thing, but that is how it is. Unfortunately, that is about where the references to Rhabdodon on television or in movies dies out, unless you have the ability to watch old episodes of Dinosaur Train. There is a Rhabdodon character named Reba on an episode or two, but none of the clips are stand alone bits from the show or available online (without the sanction of PBS) otherwise.

07 June 2015

Rabid Rhabdodon

Strangely Rhabdodon is actually a rather popular dinosaur with kids. The dinosaur shows up in the Dinosaur Train alphabet song and on the website. It also appears on some kid friendly websites other than Dinosaur Train like About and Prehistoric Wildlife.

06 June 2015

Downy 'don

©Tom Parker
It has become apparent that the discovery of feathers on more basal dinosauriformes has convinced more and more illustrators that all dinosaurs need feathering. This is, of course, not entirely universally true, but it is also not completely without merit. Regardless, the interpretation of Rhabdodon with feathers is unique, but interesting. The idea that it had little chicken legs is a little odd and the wing-like forelimbs is pretty sad looking in general. All told, Rhabdodon looks like a big downy chick with a dinosaur head in this interpretation. Quality work, a little unorthodox, but a good quality interpretation.

05 June 2015

Dwarf Iguanodons

The fluted tooth miniature Iguanodon known as Rhabdodon is a genus with two recognized species, R. priscus Matheron 1869 and R. septimanicus Buffetaut & Le Loeuff, 1991. The animals were discovered in Cretaceous soils of Europe; Spain, France, and Romania more specifically. The French material has not been assigned to either species as yet, but with two species, Rhabdodon is in a minority of dinosaur genera in that it contains multiple species. The lack of lumping of taxa in paleontology means that the French material may belong to either species but may be assigned to a third, if that trend continues. If it does not, then it will not, obviously. Either way, Rhabdodon is a "simple" Iguanodon but is a very interesting dinosaur regardless.

04 June 2015

Popular Everywhere, Maybe Even China

The discoveries of multiple specimens of Microraptor gui are the result of combined AMNH and Chinese cooperation. Some of the fossils were originally smuggled out of China and the various states of preservation even created a nomenclature issue at one point, with the genus Cryptovolans being designated for one of those fossils. Other names given to the fossils include Microraptor zhaoianus and Archaeoraptor liaoningensis. As this was a topic of much debate and contention, we have stuck with the accepted name, Microraptor gui, and not mentioned the various other names. The fossils have been popular all over though, despite their nomenclatural discontinuity. The dino-bird has appeared on the BBC and in countless other documentaries and networks over the years. It has also graced many, many pages in books. It is not much of a surprise that it has been modded into video games, and even included in the Dino D-Day game that is available on Steam. That game is well worth the paltry sum they ask for it!

03 June 2015

Small Thieves

While some thought, or think, that Microraptor was only capable of gliding flight, we saw some papers yesterday that thought it was capable of powered flight. Regardless of the actual flight abilities of the dinosaur, we know that it had feathers and that those feathers carried black pigmentation. The fossilized melanosomes sound like the subject of speculation and science fiction, but they were found, analyzed, and determined to resemble those cells associated with the color black. The cells were found in the long pennacious feathers of the dinosaur, those capable of flight. The feathers were, of course, the key trait regarding the ability to fly in these small dinosaurs. all four limbs and the tail were feathered, and that feathering constructed what appears to have been a sturdy airfoil like those found in extant birds.

02 June 2015

Biplanes and Other Papers

Sankar Chatterjee, and R. Jack Templin 
PNAS 2007;104:1576-1580
Microraptor has become a magnet for attention in a variety of ways in the scholarly article realm. There have been some regular articles, such as those describing specimens and reconstructions and descriptions of the feathering of this magnificent dino-bird. There are also inquiries into the flight capabilities of Microraptor. These include simple flight models and complex, confusing models of Microraptor in terms of the modern mechanical marvels known as biplanes. The graphic from that paper is amazing, as we can see here. As a counterpoint to much of the discussion about flight, there is also an article that states that flattened Microraptors do not lend themselves well to flight models. That is a pretty good argument, it has to be acknowledged.

Caption for the image from the paper: Wing planform of Microraptor.(A–D) Different possible hindlimb postures during flight. (A) Hindlimb backwardly directed as in modern birds. (B–D) Biplane configuration. (B)Hindlimb backwardly sloping position. (C) Hindlimb forwardly sloping in predatory strike position. (D) Hindlimb in z-fashion with a body silhouette showing the animal in lateral view with an upwardly tilted tail for pitch control. (E) Cross-section of the tibia–fibula showing a streamlining and stretching effect of the cylindrical tibia by adding feathers caudally. (F)Cylindrical structure offers maximum resistance to the airstream as the airflow behind it becomes broken up into eddies, creating turbulence. (G) Filling the spaces in a cylindrical structure in front and behind improves streamlining, as in the case of the feathered tibia of raptors. (H) Pouncing posture of a raptor, Falco. (I) A typical staggered biplane Stearman for comparison with Microraptor; in biplane aircraft of the 1920s, there was a large additional drag of wires, struts, etc. between the two wings, which eventually made the biplane obsolete except for a niche application; such drag-induced structures were absent in Microraptor. (J) Life reconstruction of M. gui(IVPP V13352) in dorsal view showing the morphology and distribution of hindlimb feathers (Left) and orientation of the hindlimb (Right) during gliding, based on Fig. 1 A; proximal feathers on the humerus and femur are inferred (data are from ref. 12). (Scale bar, 5 cm.)

01 June 2015

Movie Stars

Microraptor gui is one of the most used dinosaurs of the last ten years in the documentary circle. We saw the show dedicated to the small dinosaur yesterday, but it has been featured in many other documentaries including a segment of Planet Dinosaur from the BBC.
There are plenty of pseudo-documentaries that discuss Microraptor or "interview" the dinosaur as well. Leave it to Chicago and the Brookfield Zoo, right? The Brookfield Zoo was one of my favorite places to go as a kid in Northern Indiana, and I am glad it is still a weird, wild world there.
Their Dinosaurs Alive exhibits of the past have also had Microraptor in the gallery. Albeit as a rather poor looking specimen originally. Thankfully the later iterations looked less bird-like and more Microraptor-like (not that I have anything against birds), although it could just be the weird lighting and the angle.