Smithsonian.com

One of Mark Witton's Pterosaurs, Courtesy of the artist's Flickr page

The Life Aquatic: Let’s offer a warm Dinosaur Tracking welcome to Brain Beatty’s new blog, The Aquatic Amniote, which will “share news and insights about marine mammals, marine reptiles, and generally explore the evolution of aquatic amniotes, with special reference to the transition from terrestrial to aquatic in air-breathing, amnion-bearing, vertebrates.”

A Leg Up: ArtEvolved’s newest gallery is devoted entirely to Pterosaurs—which has prompted considerable online debate about precisely where the wings were attached on the flying dinosaur’s body. British Pterosaur specialist Mark Witton weighs in with his views: “In a nutshell: there is no support for…hip attachment, one specimen may show a knee attachment (but it’s ambiguous at best), whereas specimens of Eudimorphodon, Anurognathus, Jeholopterus, Rhamphorhynchus, Sordes, Beipopterus and a Tapejarid…all give either hints of an ankle attachment or show it quite convincingly.”

The Red Eye: “A wide variety of chemical defenses have evolved in the natural kingdom,” notes The World We Don’t Live In. “However, squirting blood from one’s eyes may seem to be taking self-defense a little too far” (agreed)—especially since the animals in question already have ample natural protection, such as spikes.

Not to be Confused with Fraggle Rock: Chinlea has posted photos of the Coelophysis Quarry in New Mexico, including the famous “Barney Rock,” which appears to be waving at visitors. (Thankfully, it doesn’t sing or dance.) According to the New Mexico Museum of Natural History and Science, “Hundreds of skeletons of Coelophysis were discovered at Ghost Ranch (Rio Arriba County) during the 1940s. This two- to three-meter-long, meat-eating dinosaur was one of the first dinosaurs on Earth and is the best-known Late Triassic dinosaur.”

Can I Phone a Friend, Regis? Catalogue of Organisms dishes up this Completely Frivolous Taxonomy Quiz. Sample question: “Current rank-based taxonomy is based on seven primary ranks. Which two were not used by Linnaeus?” (And, that’s the easiest one.) Answers are posted here. (No peeking…)

Shut Down: Paleochick offers an extensive round-up of news related to the closing of the University of Wyoming Geological Museum, which shut its doors on June 30th due to budget cuts. The museum was founded 122 years ago—and one of its first curators was William Harlow Reed, one of the railroad workers who discovered the first dinosaur fossils at Como Bluff, Wyoming. An online petition to keep the museum open currently has nearly 2,500 signatures.

The Show Must Go On? Last March, Bob’s Dinosaur Blog reported that Michael Jackson’s anticipated comeback tour had created a scheduling conflict at London’s O2 Arena with the Walking with Dinosaurs: The Arena Spectacular stage show that recently scored big box office in the United States. But…“Now, sadly, that conflict…has been rendered moot, which leads one to wonder if O2 will extend the dinosaurs’ stay to make up for Jackson’s absence.”

Megalosaurus, as depicted in Extinct Monsters.

It is difficult to look at the skeleton of a dinosaur and not imagine what it might have been like when it was alive. What color was it? What sounds did it make? How did it eat? The last question, in particular, is of perpetual interest when it comes to meat-eating dinosaurs, and many writers have tried to interpret the hunting habits of “predaceous” dinosaurs, sometimes dramatically. One attempt, made over a century ago, was undertaken by the Reverend H.N. Hutchinson in his 1894 book Extinct Monsters, in which he imagined a Megalosaurus pouncing on some unsuspecting prey:

It is not very difficult to imagine a Megalosaur lying in wait for his prey (perhaps a slender, harmless little mammal of the ant-eater type) with his hind limbs bent under his body, so as to bring the heels to the ground, and then with one terrific bound from those long legs springing on to the prey, and holding the mammal tight in its clawed fore limbs, as a cat might hold a mouse. Then the sabre-like teeth would be brought into action by the powerful jaws, and soon the flesh and bones of the victim would be gone !

Just what such a large dinosaur would hide behind is left to our imagination.

It should be noted, though, that we still do not have a very good idea of what Megalosaurus looked like. Even though it was one of the first dinosaurs to be scientifically described, no one has found a complete skeleton of it. In fact, last summer paleontologists determined that most of the fossils said to belong to Megalosaurus really represented other dinosaurs. The only “true” Megalosaurus fossil we know of is the portion of lower jaw first used to describe the genus.

"ReX" (with temporary neck brace) prepares for its big move to ImaginOn.

For the past seven years, a seven-foot-tall origami Tyrannosaurus has served as the mascot for the TEA ReX Teahouse in Charlotte, North Carolina. As The Charlotte Observer recently reported, however, the company is switching to a new online format, and the giant paper dinosaur would need a new home.

Now it has one, says TEA ReX president Wayne Powers. The origami structure is being installed in the entryway of ImaginOn, an arts and library center for children.

“ReX” was created in 1996 for an origami festival held in Charlotte every other year. According to Powers,

[The origami dinosaur] is made up of 46 pieces, each with more than 100 folds to complete the required bone shape.  It was designed by a prominent Japanese artist, Issei Yoshino, and opened up an entire new era of realistic-looking origami in the early 1990’s.  Under the direction of Southeast Origami Festival founder Jonathan Baxter, this one-quarter size prototype was folded by the Southeast Origami “D-Team”, who reside in cities throughout the southern United States and meet regularly to work on large-size origami exhibit pieces.

“ReX” was presented to Wayne Powers, in gratitude for his support of the Origami Festivals, and was prominently displayed at Powers’ TEA ReX TEAHOUSE in Charlotte’s Historic South End from 2002 until its closing in June, 2009, where he was enjoyed and regularly photographed by countless visitors from around the world.

It will be on display again next month. During the transfer, ReX will undergo “elective neck surgery,” Powers says, to reinforce a weak spot in its neck.

The Allosaurus skeleton on display at the Smithsonian.

Scientists in Spain announced this week the discovery of a large tooth from a predatory dinosaur similar to Allosaurus. Found by local residents in Riodeva, Teruel, the nearly 4-inch-long tooth is the largest predatory dinosaur tooth yet found from the country. Just what dinosaur the tooth belonged to is as yet unknown. The scientists who described it for the journal Estudios Geologicos, as LiveScience reports, are pretty confident that it came from an allosaurid, and may be closely related to the as-yet-unknown dinosaur that left similar teeth in the strata of Portugal. Whatever the dinosaur was, though, it appears to have dined on sauropods. A bone from the sauropod Turiasaurus riodevensis found in the same area as the new tooth bears a large puncture mark that appears to have been made by a large predatory dinosaur. No doubt more exciting discoveries will emerge from Riodeva.

Uncle Beazley on display at the National Zoo. From Flickr user Mo Kaiwen.

When I visited the National Zoo in Washington, D.C. earlier this year, I was a bit surprised to see a large Triceratops statue next to the giant anteater enclosure. There are a few dinosaurs at the zoo, like the Tyrannosaurus skull sculpture near the big cats exhibit, but the Triceratops seemed out of place. Why was it there?

I didn’t know it at the time, but this Triceratops was a minor celebrity. In 1956, Oliver Butterworth published a children’s book called The Enormous Egg in which a young boy discovers a large dinosaur egg. It hatches, and the boy names the young Triceratops “Uncle Beazley.” The dinosaur quickly becomes too large to handle, though, so the boy gives it to the “National Museum” in Washington, D.C.

A made-for-TV film adaptation of the story aired in 1968, and a life-sized Triceratops sculpture was created for the story. It was soon after donated to the Smithsonian by the Sinclair Oil Company, which was famous for its dinosaur logo. Uncle Beazley has been moved around a bit since that time, but today he can be seen in a special “prehistoric” garden right across from the lemur exhibit at the National Zoo.

A cast of a (real) baby Triceratops skull. From Flickr user Cryptonaut.

When I took a college course about dinosaurs a few years ago, I took the opportunity to confirm what a family member told me when I was very young. Someone had given me a small lump of irregularly-shaped rock and said it was a dinosaur bone. It certainly looked like some kind of fossil, and in 2003 I brought it to my professor to see if he knew what it was.

If my professor was sure of anything, it was that my specimen was not a fossil. It looked like a bone, sure, but it was just a small rock that had formed in a way that looked bone-like. It did not have the honeycomb-like internal structure that is a tell-tale sign of fossilized bone. Such mistakes are easily made, though, and it seems that a similar fossil-like rock has been making a bit of news lately.

This past weekend, DL-Online posted a story about a “baby dinosaur” skull discovered by Minnesota rockhound Mitchell Voss. Held the right way there is something dinosaur-like about the image on the rock, but this resemblance appears to be due to irregular swirls on the rock. This is similar to the famous (and now lost forever) Old Man of the Mountain from New Hampshire. While the side of the mountain appeared to present a human-like face, the “Old Man” was just a series of cliff ledges that, viewed from the right angle, looked like a human face. The same phenomena is at work with this “baby dinosaur”, and I have no doubt that an examination of the internal makeup of Voss’ find will reveal it to be a rock.

The wonderful exhibit “Dinosaurs: Ancient Fossils, New Discoveries” will soon be coming to the Denver Museum of Nature & Science, and to promote it the museum has commissioned a special TV ad that can only be described as “Apatosaurus on Ice.”

Unfortunately, though, some people might think this is a bit of false advertising. There are no ice-skating dinosaurs in the exhibit, but the commercial is very impressive all the same! If you want to know more about how it was made, see this article from VFX World.

The skeleton of Limusaurus (the head is to the right). From the Nature paper.

As I have written about many times here on Dinosaur Tracking, paleontologists presently have an overwhelming amount of evidence that birds are living dinosaurs. That doesn’t mean that everything about the dinosaur-to-bird transition is well-understood, though. For years scientists have been faced with a puzzle involving the hands of living birds and bird-like dinosaurs. The dinosaurs most closely related to birds appeared to have a thumb and two fingers (digits I-II-III) while studies of the embryonic development of birds showed that they have fingers II-III-IV. This difference would have to be accounted for, and a bizarre new theropod dinosaur described by an international team of scientists in yesterday’s edition of Nature provides a crucial clue to this fossil puzzle.

The new dinosaur, named Limusaurus inextricabilis, is so strange that I almost don’t know where to start describing it. It lived about 156 million to 161 million years ago in what is now western China, and it was one of the dinosaurs that became mired in the famous “Dinosaur Death Trap” featured by National Geographic. Yet while scientists were able to identify it as a ceratosaur, one of the early groups of theropod dinosaurs, it was like no other ceratosaur they had ever seen. Instead of packing a mouthful of sharp teeth, like Ceratosaurus, Limusaurus did not have a tooth in its entire mouth! A pile of stones was found in its stomach region that probably ground up food inside its gut, and it is likely that this theropod dinosaur was actually a herbivore.

What is making headlines, though, is that Limusaurus had at least one feature that is very important to understanding how avian dinosaurs (i.e. birds) evolved.  Since we know that theropod dinosaurs evolved from five-fingered ancestors, it has long been assumed that, to end up with digits I, II and III, they lost two fingers: their pinky and ring fingers (or digits IV-V). In this way the fingers were reduced and lost, probably due to changes during embryological development, from the outermost finger moving in. What Limusaurus shows, though, is that after some dinosaurs lost their pinky they began to lose their thumb.

This is not what would have been expected, but it is clear that Limusaurus has a greatly reduced thumb and an enlarged second digit. In this way the second finger functionally became like a thumb, but what if Limusaurus was just an oddball? We can’t know if it was directly ancestral to any other dinosaurs, but the paleontologists then looked at the hands and fingers of other dinosaurs more closely related to birds (the coelurosaurus) and found their answer not in the finger bones, but in the wrist bones. The finger bones of these later dinosaurs alone might make it hard to tell if they were really I-II-III or II-III-IV, but the wrist bones provided a clearer picture. The wrist bones of dinosaurs more closely related to birds did not change as much as the fingers. They retained signs that the modified finger bones they were attached to were really II-III-IV, and this finally makes sense of both the fossil and embryological evidence.

Now keep in mind that Limusaurus is probably not directly ancestral to the dinosaurs that gave rise to birds. It is not a “missing link” (and the phrase “missing link” itself is more confusing than helpful when thinking about evolution).  What the skeleton of Limusaurus suggests, though, is that there was a significant shift in hand shape going on among ceratosaurs during the Jurassic, and Limusaurus provides a window into how this change occurred. If the hypothesis of the authors is correct, and there is much reason to think it is, then we should expect to find other theropod dinosaurs with similar hand anatomy that link some ceratosaurs to tetanuran dinosaurs, the group to which coelurosaurs (and hence birds) belong.

There is much more to discuss about Limusaurus than any one blogger can cover, though, so have a look at what some other science bloggers have to say about this new find:

Archosaur Musings

Chinleana

The Loom

When Pigs Fly Returns