A brachiosaur topiary. Photographed by Mo Hassan.

Today’s Dinosaur Sighting comes to us from science blogger Mo Hassan (”The Disillusioned Taxonomist“). Mo spotted this topiary brachiosaur while visiting the Van Hage Animal Centre in Ware, Hertfordshire, England,  though it was nowhere near as large as some of the real brachiosaurs got millions of years ago.

Have you stumbled across a dinosaur in an unexpected place? If you have, and have a photo of the encounter, send it to us via dinosaursightings@gmail.com!

An early look at the "Dinoshark" from SyFy's film of the same name.

I may be completely wrong, but somehow I get the feeling that somewhere on a wall at SyFy Channel headquarters there is a special dartboard. On it are the names of large, predatory animals like “Shark,” “Smilodon,” “Giant Squid” and “Dinosaur,” and when the company executives run out of ideas they resort to throwing darts to determine what sort of movie they are going to make next. If this is true then it would seem that the filmmakers have been changing things up by throwing two darts at the board and combining whatever creatures are hit. That is the only way I can explain the origin of the forthcoming SyFy films Sharktopus and Dinoshark.

So far Sharktopus has been getting the most buzz around the web (even if it has been done before), but since the film is just in the planning stages it will be a while before it will debut for fans of “so-bad-they’re-almost-good” movies. Dinoshark will surface much sooner. It is set to air on March 13, but other than that details on the movie are slim. I have not seen a synopsis of a plot so far, but who really needs one? In an interview with the film’s producer, Roger Corman, the veteran b-movie maker, said:

“Global warming causes the glaciers to break apart,” Corman explains. “We start the picture with real beautiful shots of the glaciers falling into the ocean. The unborn egg of the Dinoshark that has been frozen for millions of years is released.”

I can only imagine what comes next. Boats and people start going missing, our heroes suspect there’s a Dinoshark on the loose, no one believes them, the body count continues to rise, etc. High art it’s not, but if you love creature features (and I have to admit that I do) you might want to invite over some friends, pop some popcorn and make fun of the b-movie cheesiness that is Dinoshark.

Allosaurus and Stegosaurus are just two of the dinosaurs that could appear on "Terra Nova." Image from Wikipedia.

Steven Spielberg, the director of the first two Jurassic Park films,  may not be done with dinosaurs yet. Even though plans for another JP film have only just begun to come together, rumor has it that the famous producer and director will be helming a new television project called “Terra Nova.” Little is known about it so far, but according to the blog io9 the premise of the show will bring people into contact with prehistoric creatures:

Following a family from 100 years in the future who travel back in time 150 million years to the strange and inhospitable environs of prehistoric Earth.

Nobody knows when the show will start filming or when the first episodes might appear, and early reports have suggested that the show’s special effects will be so elaborate that it will bypass the traditional “pilot” phase and go straight into full production. This is may be good news for dinosaur fans. If the show’s protagonists are sent back in time 150 million years, they will almost certainly run into some dinosaurs and other prehistoric critters, and a big special effects budget will ensure that the creatures look much, much better than the claymation monsters of the old Land of the Lost television show. (Ed. — What, you don’t like Sleestaks?)

What sort of animals might the show feature? If it is set 150 million years ago, as early reports suggest, then it would take place during the waning days of the Jurassic during a subdivision of time called the Tithonian. During this time there were already feathered dinosaurs (like Archaeopteryx) and early representatives of famous groups of Cretaceous dinosaurs (such as the ankylosaurs and horned dinosaurs) were already running about.

Unfortunately for fans of Tyrannosaurus, though, the show would take place too early for the most famous of dinosaurs to make an appearance. During the Late Jurassic the relatives of Tyrannosaurus were still pretty small and probably covered with feathers. (Stokesosaurus, an approximately 12-foot-long relative of Tyrannosaurus found in England and Utah, was about as big as early tyrant dinosaurs got.) There were still plenty of other large predatory dinosaurs, though. Allosaurus and Torvosaurus were among the top predators of the time, though (in my opinion, anyway) some of the weirdest and most wonderful large theropods were those present a few million years later during the Early Cretaceous.

A restoration of Asilisaurus. Darker areas are missing portions of the skeleton. From the Nature paper.

What were the very first dinosaurs like? This is one of the most vexing questions in vertebrate paleontology. Even though paleontologists have found a number of early dinosaurs in recent years, details about the very first dinosaurs and their close relatives have been hard to come by, but in a new paper published this week in Nature paleontologists report an animal that helps put the origin of dinosaurs in context.

Dinosaurs did not just pop into existence out of nothing. All the numerous dinosaur lineages we know and love can be traced back to one common ancestor, and that animal was itself just part of another diverse group of creatures. To put it another way, all dinosaurs compose one group (the Dinosauria) which is nested within an even larger group called the Dinosauriformes, or dinosaurs plus their closest relatives. (We will stop here, but you could keep on going down the family tree all the way back to the first life on earth if you wanted to.)

The new creature described by paleontologists Sterling Nesbitt, Christian Sidor, Randall Irmis, Kenneth Angielczyk, Roger Smith and Linda Tsuji helps to better resolve these relationships. Discovered in 243-million-year-old rock in Tanzania, Asilisaurus kongwe was a close relative of earliest dinosaurs, but it was not ancestral to them. Instead the Asilisaurus illustrates that the group to which it belonged, the silesaurids, split from the earliest dinosaurs earlier than was previously thought and thus suggests that there is another 10 million to 15 million years of early dinosaur evolution yet to uncover.

The species’ bearing on questions about dinosaur origins is what has made headlines, but outside these considerations Asilisaurus is still a remarkable find. The paleontologists who discovered it found the remains of at least 14 individual animals, and altogether they have been able to piece together almost the entire skeleton. It was a slender animal, with a long neck and small hands, that moved about on all four limbs. What it ate is not definitely known, but its leaf-shaped teeth would have allowed it to be a herbivore or an omnivore. This latter point is especially significant because, like the earliest herbivorous dinosaurs, Asilisaurus evolved from a carnivorous ancestor, meaning that among the dinosauriformes, plant-eating forms independently evolved at least three times.

Compared alongside its close relatives and contemporaries, Asilisaurus suggests that by 245 million years ago there was a major radiation of archosaurs (an even more inclusive group of vertebrates which contains dinosaurs, pterosaurs, crocodiles, and their extinct relatives). At this time dinosaurs were not yet the dominant large vertebrates, but instead were just part of a greater diversity of types now extinct.

For more on this discovery, see this post as Chinleana.

Nesbitt, S., Sidor, C., Irmis, R., Angielczyk, K., Smith, R., & Tsuji, L. (2010). Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira Nature, 464 (7285), 95-98 DOI: 10.1038/nature08718

A partial restoration of Microraptor showing how the wrist could be flexed. From the Proceedings of the Royal Society B paper.

If there is one persistent gripe that paleontologists have with dinosaurs on screen, it is that their hands are usually wrong. From Tyrannosaurus to Velociraptor, predatory dinosaurs are time and again shown with their hands in a palms-down position, something that would have been anatomically impossible (at least without moving the arms to which those wrists were attached to). This does not mean that the wrists of theropod dinosaurs were inflexible, though. As reported in a new study just published in the Proceedings of the Royal Society B, some theropod dinosaurs had a unique wrist structure that may have greatly influenced the evolution of birds.

Take a look at your own hands for a moment. Stick one out in front of you so that your palm is oriented straight up-and-down. Now imagine that you could bend your wrist so much on the “pinky” side that your fingers would be pointing straight backwards towards your elbow. That is what birds can do, and it is important to the way they fly and fold up their wings when on the ground.

As with many other “bird” characteristics, though, this feature evolved first among dinosaurs, and it probably had its beginnings in something that did not have anything at all to do with flight. As outlined by paleontologists Corwin Sullivan, David Hone, Xing Xu and Fucheng Zhang in their new study, the evolution of a peculiar wrist bone in theropod dinosaurs called the semi-lunate carpal allowed the wrists of predatory dinosaurs to become more flexible. This may have had something to do with hunting, but regardless of the reason why it evolved, it set the stage for the evolution of increased wrist flexibility among the ancestors of birds.

Maniraptoran dinosaurs were a diverse group, containing an array of feathered dinosaurs from the weird therizinosaurs to the famous “raptors” and birds, and as this group evolved many lineages were adapted to have greater wrist flexibility. This can be seen in their anatomy: the degree of asymmetry in the wrist bones provides an indication of how far the wrist could be flexed. Not surprisingly, the feathered dinosaurs most closely related to birds show the greatest amount of flexibility, but why were their wrists adapted in this way?

Nobody knows for sure. It had originally been proposed that this flexibility could be attributed to hunting, but the same changes are seen in maniraptorans that were herbivores and omnivores so it is unlikely that hunting provides the answer. Instead, the authors of the new study propose, the ability to fold the hands backwards would have protected the feathers of the arms. This would have prevented the feathers from getting damaged or from being in the way as the dinosaurs moved about, although the authors recognize that this hypothesis requires further evidence.

Perhaps more significant, however, is how this wing-folding mechanism may have allowed birds to take to the air. Birds do flex their wrists while flapping their wings to fly, and so it appears that the wrist flexibility that first evolved in dinosaurs was later co-opted for flight in birds. This is what is known as “exaptation,” or when a previous adaptation takes on a new function. Indeed, as more is discovered about the evolution of birds, the more traits paleontologists find that evolved for one function but have been co-opted for another at a later point (feathers themselves being the most prominent example). There is relatively little separating birds from their feathered dinosaur ancestors.

For more on this new study see Not Exactly Rocket Science and Dave Hone’s Archosaur Musings.

Corwin Sullivan, David W. E. Hone, Xing Xu and Fucheng Zhang (2010). The asymmetry of the carpal joint and the evolution of wing folding in maniraptoran theropod dinosaurs. Proceedings of the Royal Society B : 10.1098/rspb.2009.2281

The remains of the fossil snake Sanajeh (left) associated with sauropod eggs (upper right) and a partial baby sauropod skeleton (lower right). From the PLoS Biology paper.

When discussing dinosaurs, the topic of what they ate often comes up, but what about the creatures that ate them? Obviously some dinosaurs ate other dinosaurs, but the famous prehistoric archosaurs were not immune to predation from other kinds of hunters, especially when the archosaurs were babies. In 2005, for example, paleontologists described a specimen of the 130-million-year-old mammal Repenomanus giganticus with the remains of baby dinosaurs preserved inside it, and now a new study in the journal PLoS Biology adds a prehistoric snake to the list of dinosaur predators.

About 67.5 million years ago, in what is now western India, sauropod dinosaurs laid nests of up to 12 eggs. Unlike their parents, the developing and newborn sauropods were not large enough to defend themselves from most predators, and so it is not surprising that the bones of the newly-described snake Sanajeh indicus seem to be common among the preserved dinosaur nests. At an estimated 3.5 meters long, this boa-like snake would certainly have been large enough to eat baby dinosaurs for breakfast, and one peculiar specimen suggests that it did so.

Even though there are many associations between sauropod nests and snake bones, one particular fossil appears to show a Sanajeh caught in the act of nest robbing. The remains of the snake are coiled around a crushed sauropod egg, with an additional two eggs and the partial skeleton of a baby sauropod found right next to it. By all appearances this snake died in a sauropod nest when a storm caused a mudslide, burying predator and prey together.

Interestingly, though, it appears that the snake did not simply swallow the eggs. According to the authors of the new study, Sanajeh had a relatively limited gape, so instead they propose that the snake crushed dinosaur eggs with its body and then ate the contents of the eggs. Baby sauropod dinosaurs probably outgrew the threat of predation from these snakes by time they were about one year old, the authors estimate, but in the egg and as newborns they were very vulnerable.

Jeffrey A. Wilson, Dhananjay M. Mohabey, Shanan E. Peters, Jason J. Head (2010). Predation upon Hatchling Dinosaurs by a New Snake
from the Late Cretaceous of India PLoS Biology, 8 (3) : 10.1371/journal.pbio.1000322

The well-preserved skull of the new sauropod Abydosaurus. From the Naturwissenschaften paper.

Utah’s Dinosaur National Monument is best known for the exquisite collection of Jurassic-age fossils that have been discovered there since the beginning of the 20th century, but what is less well known is that more recent Cretaceous critters can be found there, too. When I visited the national park last summer I dropped by a dig being undertaken by paleontologists from Brigham Young University which had turned up the remains of  a predator akin to Deinonychus and a sauropod that would have looked like a smaller rendition of Brachiosaurus. At the time these dinosaurs did not have names, but now paleontologists Dan Chure, Brooks Britt, John Whitlock, and Jeffrey Wilson have finally given a name to the large herbivore.

At first the presence of sauropod dinosaurs alongside “raptors” might seem like an anachronism. The long-necked plant eaters were the dominant herbivores during the Jurassic, but for years what paleontologists saw in the fossil record suggested that they were all but wiped out by the Cretaceous. (Alamosaurus, a sauropod that may have lived alongside Tyrannosaurus, was an exception.) As scientists have continued their research, however, it has come to light that there were a number of sauropods that lived during the Early Cretaceous (146-100 million years ago) of North America, and the new genus from Dinosaur National Monument is one of them. It is called Abydosaurus mcintoshi.

What is truly amazing about Abydosaurus is that among its remains paleontologists found a complete skull. As big and heavy as the rest of their skeletons were the heads of sauropods were light and relatively easily detached, and more often than not those skulls are never found. Finding the skull of any sauropod is cause for excitement, and the discovery of the Abydosaurus cranium is all the more special because it is the first complete skull to be found from an Early Cretaceous sauropod from North America. It is truly a beautiful specimen, and based upon what I saw at the dig expect to see much more of Abydosaurus in the months and years to come.

Chure, D., Britt, B., Whitlock, J., & Wilson, J. (2010). First complete sauropod dinosaur skull from the Cretaceous of the Americas and the evolution of sauropod dentition Naturwissenschaften DOI: 10.1007/s00114-010-0650-6

Dinosaur snow sculptures. H/T to SV-Pow!

Going for Broke: What do you do if you break a bone? (A dinosaur bone, that is.) Well, once you get over the humiliation of breaking something that has remained intact for several million years, David Hone at Archosaur Musings has a practical guide on how to deal with the problem.

The Young and Restless: Young Earth Creationists contend that all life on the planet was created sometime between 5,700 and 10,000 years ago. The blog Stupid Dinosaur Lies presents a detailed taxonomy and debunking of these arguments, otherwise known as “The Seven F’s of Young Earth Creationism: Fictional, Framed, Foredoom, Fascism, Fanaticism, Feint, and Folly.”

Connective Issue: The Disillusioned Taxonomist challenges readers to solve a photographic puzzle: “What’s the connection between the following animals?” (Including a fossilized trilobite and a lion.) The answer is here.

Interpretative Art: Peter Bond at ART Evolved presents a gallery of therizinosaur sketches and paintings. (One portrayal resembles an oversized, carnivorous zebra-striped turkey.) “Therizinosaurs have had a long and convoluted history when it comes to reconstructions. Meat-eater or plant-eater? Prosauropod or coelurosaur?  Skin or feathers? These questions led to wild variations in what a therizinosaur looked like!”

Blasts From the Past: Catalogue of Organisms presents “A Beginner’s Guide to Blastoids.” (Coolest. Species. Names. Ever.)

Psychedelic Trilobites: Walcott’s Quarry bemoans the lack of color in fossils, prompting two trilobites to experiment with a bold new look.

Saltasaurus and Peppernychus: Love in the Time of Chasmosaurs exalts over a discovery in an antique shop: A vintage pair of dinosaur salt and pepper shakers. Apparently, the design concept is quite rare: “This is, in my opinion, one of the most grievous oversights in the history of kitchenware. Disgraceful.”

Ice Age: SV-POW! posts remarkable photos that are a guaranteed cure for the winter blues: giant sauropod snow sculptures.

A T-Rex Walks Into a Bar: “Perhaps because they’re no longer around to lodge any objections, dinosaurs (and other prehistoric reptiles) have increasingly become the butt of kindergarten-level knock-knock jokes,” notes Bob’s Dinosaur Blog, which presents a few of his own humorous quips.

Earlier this month, I shared a how-to video of how to make a balloon Tyrannosaurus, but if you don’t like balloon animals there is another way to make a neat little dino. With just a square piece of paper you can make your very own “snapping” dinosaur, and the above video will show you how.

A specimen of Microraptor gui under UV light. The white arrows point to preserved tissue, the black arrows point to a "halo" around the body where feathers are not present, and the gray arrows point to preserved feathers. From the PLoS One paper.

Since 1996 paleontologists have found so many feathered dinosaurs that it has been impossible to keep up with them all. There are scores of exceptionally preserved specimens that have yet to be fully studied and published upon, but, according to a new study in PLoS One,  there is still plenty to learn about the few that have already been introduced in the literature.

Of the feathered dinosaurs discovered so far, Microraptor gui is among the most famous. Long flight feathers which were attached to its arms and legs and are plainly visible to the naked eye, made it a four-winged dinosaur. But until now scientists have been unsure whether some of the other preserved feathered around the body remained in their natural position (i.e. attached to the body) or had been moved around afterwards. To resolve this question, paleontologists David Hone, Helmut Tischlinger, Xing Xu and Fucheng Zhang decided to use UV light to see how the preserved feathers related to the rest of the body.

Paleontologists have been using UV light to study the details of fossils for a long time, but the practice had not yet been extended to the feathered dinosaurs of China. Under this light details that might elude scientists under normal lighting can more clearly be seen, and what the paleontologists found was that the feathers of Microraptor did indeed extend into the “halo” around the fossil that represented its body, and sometimes the feathers extended almost all the way to the skeleton. The feathers were not just strewn about as if they had fallen off after death; they were preserved in their natural positions.

This finding is important for two reasons. The first is that paleontologists can now be confident that the Microraptor specimen that was studied provides a good look at the external anatomy of the animal. More importantly, however, this sort of technique can be extended to the scores of similarly-preserved fossils from the same region. Using UV light, paleontologists will be able to better understand how feathers were attached to the bodies of dinosaurs, and added to new findings about the colors of feathered dinosaurs, scientists will be able to bring the past to life like never before.

For more on this study see the blog of its lead author, David Hone, called Archosaur Musings.

Hone, D., 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) DOI: 10.1371/journal.pone.0009223

Called “Dinosaurs Unleashed,” the exhibition features two dozen dinosaurs that will be on display along Oxford Street until the end of April. While some of the dinosaurs are placed around prehistoric-looking plants, the real draw is the chance to see the animatronic robots in the middle of the city. Who knows? Maybe anachronistic displays of dinosaurs in the city will even inspire someone to write the next “dinosaurs run amok” blockbuster.

An early restoration of a vaugely crocodile-like Megalosaurus.

Dinosaurs as depicted in museums, movies and art today are sleek, brightly-colored and often feathered. This was not always the case. When dinosaurs were first recognized by science at the beginning of the 19th century, naturalists like Gideon Mantell and William Buckland thought they looked like enormous lizards and crocodiles. Iguanodon, as its name might suggest, was thought to be a gigantic version of the tropical lizards, and Megalosaurus was envisioned as a more crocodile-like beast.

Buckland, in particular, was enthralled by these ancient creatures. They were the petrified evidence of a past world that had flourished and been destroyed during a past beyond memory, and (as later recounted by his son Francis) Buckland once described the great Megalosaurus this way:

During this period of monsters there floated in the neighborhood of what is now the lake of Blenheim – huge lizards, their jaws like crocodiles, their bodies as big as elephants, their legs like gate-posts and mile-stones, and their tails as long and as large as the steeple of Kidlington or Long Habro’. Take off the steeple of either church, lay it in a horizontal position, and place legs on it, and you will have some notion of the animal’s bulk. These stories look like fables, but I ask not your indulgence to believe them. There the monsters are, and I challenge your incredulity in the face of the specimens before your eyes; – disbelieve them if you can.

It was impossible not to be fascinated by such creatures, and they were so spectacular that Buckland thought the fossils of these dinosaurs may have inspired myths and legends:

May not the idea of the dragons, curious stories of which are chronicles in various parts of England, owe their origin, in some way or other, to the veritable existence of these large lizards in former ages? To point out the train of ideas or circumstances which led to these ancient dragon stories is of course impossible, particularly as man was not coexistant with Megalosaurus and Co. – still there is a certain shadow of connexion between them.

Buckland left this question open, but over a century and a half later the historian Adrienne Mayor would illustrate that he was on the right track. The mythology of many cultures, from Native American tribes to the Greeks, was heavily affected by the discovery of fossil bones. The Thunderbird, the Cyclops, Griffins, dragons and more were not just figments of our imagination, but early attempts to make sense of strange fossil bones found throughout the world.

A reconstruction of Albertosaurus. From Wikipedia.

Last week kicked off the 2010 Winter Olympics in Vancouver, Canada, and as we all know Canada has some really fantastic dinosaur deposits. In fact, one of my favorite dinosaurs, the tyrannosaur Albertosaurus, hails from the province right next door to the one in which this year’s Olympics are being held. Maybe it is a bit of a stretch, but I can’t help but wonder which Olympic event Albertosaurus might excel at if it could compete.

I don’t imagine that curling or luge would allow Albertosaurus to make the best of its talents, and the biathalon might be dangerous since the other competitors would be packing heat, but if the dinosaur could pull it off I think Albertosaurus could deliver one of the most fantastic figure skating routines ever seen. The stride of Albertosaurus might give it an edge in the cross-country skiing event, too, although judges would have to make sure none of the other competitors mysteriously disappear.

Logo of the "feathered dinosaur protest movment", from I Heart Chaos.

Time and again I have used this blog to describe what I think is one of the most fascinating recent discoveries in paleontology: that birds are dinosaurs.

Not everyone is happy with this fact, though. The blog io9 recently posted sample images from a feathered dinosaur protest group who prefer their dinosaurs to be scaly. According to the “skeptics”: “Dinosaurs are naked, leathery killing machines. They’re not Brazilian Carnivale queens.” Never mind that feathered dinosaurs are a fact (the fossils don’t lie); if you want to join the movement you can get stickers to show your support here.

The poster for the first Jurassic Park film. Will there be a fourth? (Image from Wikipedia)

It is hard to know what to believe about the Jurassic Park franchise anymore. About 15 months ago the rumor was that the series had been dropped, but half a year later a studio exec stated that the prospect of bringing the dinosaurs back was still on life support. According to Hollywood scuttlebutt, producers were hoping to take the series in a new direction and were not going to make a move until they had something fresh.

In fact, a few years ago the studio had something that may have departed a little too far from the previous films. A leaked script for an early version of Jurassic Park IV featured super-smart, gun-toting raptors as main characters, and it definitely would have been one of the strangest big-budget films ever made.

But as revealed by the director of Jurassic Park III, Joe Johnston, that idea was scrapped long ago. Making the rounds to promote his new film, The Wolfman, Johnston mentioned to HitFix that ideas for a fourth dino-blockbuster are starting to come together:

Is [the gun-toting dinosaurs idea] still in the offing, or have you moved on now to a new idea?

Johnston: We have. There is an idea now for number four that is different from the first three, and that is more or less the beginning of a new triology, in that it sends the whole franchise off in a new direction. It’s not about the dinosaur park anymore. It’s about all-new characters. So Steven [Spielberg is] busy right now with the stuff he’s doing and I’ve got to do “Captain America,” but hopefully afterwards, we’ll find time to develop it. And really… it’s something different that we haven’t seen before in the “Jurassic Park” world.

So, if this is accurate, Johnston might very well be back as the director for a fourth installment, which itself will be something of a reboot for the whole franchise. What could these new ideas be? We probably won’t find out for a while. The Captain America movie is not slated to come out until the summer of 2011, and who knows when Spielberg will be available again. It will probably be another few years before the dinosaurs come back.