Imagine an apatosaurus with a long, elephant-like snout. Plenty of people have. That's because the nostril placement on sauropod dinosaurs is, in some ways, remarkably similar to that of trunked animals that live today. In both cases, the nostrils are large, and they're located up around what we'd call the forehead, kind of smack between the eyes.
On the one hand, this is one of those things that it's really hard to ever know for certain. We don't have preserved soft tissue, so when we make models of what dinosaurs might have looked like we're really going on clues from the bones and comparisons to living animals with similar bone structure. Because of that, it is somewhat reasonable to suggest that hey, maybe, sauropods really did look like grumpy diplodocus in the image above. It's fun to speculate.
But not all speculations are created equal. In a fascinating post at the Tetrapod Zoology blog, Darren Naish explains why a superficial similarity to trunked animals isn't enough to counteract the much-more prevalent evidence against sauropod trunks. One of the more interesting lines of evidence he points out is the fact that dinosaurs apparently lacked the facial which form the trunk in living animals. We know this partly because muscles leave their signature on bone, and Naish says there's no evidence sauropods had the right facial muscles. It's further bolstered by the fact that the animals most closely related to sauropods don't have those facial muscles, either.
Naish's piece reminds me of the last time we talked about sauropod biology here. That, too, dealt with the fact that superficial similarities aren't enough to infer that two animals must have identical biology. Only, in that case, we were talking about the differences between the long necks of giraffes and the long necks of sauropods.
I'm at the National Association of Science Writers conference this weekend and, in a panel on creating narrative in journalism, author George Johnson mentioned something absolutely fascinating. Johnson is currently writing a book about cancer and he told the audience a story about traveling out to see specimens that showed a metastasized cancer in the fossilized bones of a dinosaur.
I think Johnson just sold me a copy of his book, but I also wanted to look up this phenomenon right now. I'd honestly never heard of dinosaur cancer, but it turns out that there are several examples of this, including a fossilized brain tumor discovered in 2003. That said, there does seem to be some debate on the subject. While that brain tumor was found in the skull of a relative of the T. Rex, another study published the same year found that only duck-billed dinosaurs seemed to have had much of a risk of cancer. In that study, scientists x-rayed 10,000 specimens. They only found cancer in the duck-billed hadrosaurs.
Now, on the one hand, this might not be totally representative of all cancer risk. After all, what you're seeing in fossils are cancers of the bone, or cancers that have metastasized to the bone. On the other hand, if this is an accurate reflection of the nature of cancer in dinosaurs, it's a pretty interesting finding, which suggests that genetics played a huge role in determining which dinosaurs got cancer and which didn't. Either that, or duck-billed dinosaurs were exposed to some kind of environmental risk factor that didn't affect other species. (Which isn't a totally crazy idea. For instance, we know that hadrosaurs grazed heavily on conifers. And, according to the 2003 paper, they may have been the only dinosaurs who preferred that diet.)
There's lots of good stuff to read on this:
Edit: Yesterday, I said David Quammen was the author writing a book about cancer. That was incorrect. It is fixed now.
• Read the full 2003 study on the epidemiology of cancer in dinosaurs
• In 1999, the same researchers published a short report on bone cancer in dinosaurs. You can read that online, too
• A 2007 paper compared rates of bone cancer in dinosaurs with those in modern vertebrates. According to this research, the rate of bone cancer hasn't changed.
• A 2010 paper looked at modern cancer treatments in the context of what we know about cancer in ancient times — both in dinosaurs and in human mummies
Edit: Yesterday, I said David Quammen was the author writing a book about cancer. That was incorrect. It is fixed now.
With their big, bitey teeth and teeny, ineffectual arms, it can be difficult to picture how Tyrannosaurus Rex actually managed to eat anything. After all, all of our personal experience with eating involves an awful lot of gripping with the forearms. Some new research, takes a stab at understanding T. Rex table manners. The results are pretty neat — and they highlight the similarities between dinosaurs and birds — but I want to make a bit of a bigger deal out of the methodology.
Several times on this blog, we've talked about the importance of the vast archives of archaeological and paleontological specimens that are sitting around in storage at museums and universities. Some of these things have never even been removed from the matrix of burlap and plaster used to secure them for shipping. Some have sat there for decades, enjoying only a cursory glance from researchers. But when scientists finally start sifting through these unseen specimens, they often find fascinating things.
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At The Dinosaur Tracking blog, Brian Switek is starting a cool, new series meant to highlight the lesser-known dinosaurs that the public as long ignored. Sure, it's a bit easier to pronounce Tyrannosaurus, but Agujaceratops and Zalmoxes still deserve their 15 minutes of fame.
The alphabetical series kicks off today with the aforementioned Agujaceratops. Found in Texas, Agujaceratops is distinctly different, in several ways, from its cousins that have been found in the northern part of North America. In fact, writes Switek, Agujaceratops is so different, that it's making paleontologists reconsider ancient North American geography.
At the species and genus levels, the southern dinosaurs are different. The big question is, why? Paleontologists know that a shallow, vanished seaway separated dinosaurs on eastern and western subcontinents for millions of years, but on that western subcontinent called Laramidia, there was apparently some other kind of barrier that isolated northern and southern dinosaur populations.
The hypothesis relies on basic evolutionary theory. Isolate populations of an ancestor species in different regions, and through factors such as natural selection and genetic drift, those populations will evolve in different ways. The fact that Agujaceratops, Kosmoceratops and Utahceratops are so different from Chasmosaurus and other northern cousins are a sign that such a barrier was in place. No one has found it yet, though, and a great deal of work remains to be done on whether all these dinosaurs were really contemporaries or reveal a much more complex evolutionary pattern. As these investigations continue, though, Agujaceratops will continue to play an important role as a symbol of isolation and evolution.
Follow along with the Dinosaur Alphabet at the Dinosaur Tracking blog
Yesterday, I posted about Pegomastax africanus, a parrot-like dinosaur whose fossil was discovered not in a remote waste in some far corner of the world, but in a rock that had sat in storage at Harvard University for 50 years.
In the post, I tried to explain why something like that could happen. The simple fact of the matter: A successful archaeological or paleontological dig will produce far more material than the original scientists have time (or money) to sort through, process, and examine. So lots of stuff ends up sitting in storage.
That led BoingBoing reader Matt Fedorko to some interesting speculation:
"...This seems like a perfect opportunity to exploit 3D scanning technology to put the shapes of fossils, at least, into some kind of digital storage area where other researchers could look at a dig's haul and start to work with them spatially, or beside any of the other data that is collected in the field or logged during the cataloging procedure."
Now, Charles Q. Choi, a journalist who wrote about the discovery of Pegomastax africanus, says that Matt's idea isn't all that far-fetched. In fact, scientists already do something like this with the fossils that do get closely examined.
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This is an artists' rendition of Pegomastax africanus, a 200-million-year-old dinosaur that is the subject of a new peer-reviewed research paper out this week in the journal ZooKeys.
It's a great face, and a fascinating species. Couple of things here that I think are worth highlighting:
First, despite the fang-y teeth Pegomastax africanus is sporting, the scientists who wrote the paper think this animal was actually a vegetarian. Or, at least, mostly a vegetarian. At LiveScience.com, the researchers told journalist Charles Q. Choi that the dinosaur had a parrot-like beak, its fangs weren't positioned well for cutting through meat, and its back teeth look like the kind of chompers plant-eaters use to slice through leaves and roughage. All of which suggest Pegomastax africanus ate more seeds, nuts, and fruit than flank steak.
The other cool thing has to do with when Pegomastax africanus was found. While the paper describing the fossil was published online today, the fossil itself was pulled out of the ground in the 1960s. In fact, the paper's main author — paleontologist Paul C. Sereno — first noticed the neglected fossil in 1983, and only recently got around to examining it more closely. Think of it this way, a successful dig might come out with lots of potentially cool rocks and fossils. The fact is that there are often more artifacts than there is time for one team to closely work with all the artifacts. The researchers who did the digging will focus on the ones that are most interesting to them. The rest get catalogued. Maybe the original researchers come back to them; maybe they don't. Maybe somebody else picks up the catalogued fossils; maybe it takes 50 years for that happen. But what this reminds us is that there are cool things waiting to be discovered in storage ... not just in the ground.
Read the full paper, which puts Pegomastax africanus into context as a member of a family of dinosaurs called heterodontosaurids.
FlippyCat's animated 3D domino depiction of the comet-strike extinction of the dinosaurs is both poignant and exciting, and the setup/blooper-reel that follows the main action is a real nail-biter.
Also known as domino-saurs
This took 38.5 hours of setup time, over about 2 weeks.
This project contains several smaller projects that I have wanted to do for a long time...the earth being hit and spreading out (since I did this with flags), the eggs revealing something behind them, a fossil/skeleton and a domino-saur!
The Fall of the Dinosaurs (Thanks, Fipi Lele!)
The correct answer is, of course, Ankylosaurus.
We think of giraffes as long-necked creatures, but compared to ancient sauropod dinosaurs (a family that includes the brachiosaurus and apatosaurus) even the longest-necked giraffe may as well be nicknamed "Stumpy". In a paper published online at arXiv site, two paleontologists analyzed the biology of sauropods in an attempt to figure out which features allowed the dinosaurs to grow necks six times longer than giraffes.
Turns out, there are some distinct differences — especially in the anatomical architecture of the vertebra closest to both animals' skulls — that really stand out. As this helpful slide shows, a sauropod with the vertebra of a giraffe would be in very bad shape, indeed.
This paper, by the authors' own account, began life "as a late-night discussion over a couple of beers", which means it's basically the paleontology equivalent of "Who would win in a fight: Darth Vader or Superman?" Which is awesome. Better yet, the paper is quite easy to read and the information is organized in a way that will probably make more sense to you than the typical scientific research paper. So dig in! It's worth it! Here's one short excerpt taken from a part discussing some of those differences in the cervical vertebra (the aforementioned vertebra closest to the skull):
Many groups of animals seem to be constrained as to the number of cervical vertebrae they can evolve. With the exceptions of sloths and sirenians, mammals are all limited to exactly seven cervicals; azdarchids are variously reported as having seven to nine cervical vertebrae, but never more; non-avian theropods do not seem to have exceeded the 13 or perhaps 14 cervicals of Neimongosaurus, with eleven or fewer being more typical.
By contrast, sauropods repeatedly increased the number of their cervical vertebrae, attaining as many as 19 in Mamenchisaurus hochuanensis. Modern swans have up to 25 cervical vertebrae, and as noted above the marine reptile Albertonectes had 76 cervical vertebrae. Multiplication of cervical vertebrae obviously contributes to neck elongation.
Via Bora Zivkovic
There are many forms of art –- still life, abstract, landscape, digital, cubism, marine, aviation, splatter, modern, photography etc but chances are, few people know what "paleoart" is. Well, simply put, it is the illustration of prehistoric life. Its practitioners combine an understanding of such broad disciplines as anatomy, geology and botany to open windows onto the ancient past, bringing to life as best they can organisms from across the planet’s four billion-year history. Everything from jellyfish to trilobites to mammoths to the first single-celled organisms – and, of course, dinosaurs.
Dinosaur Art is a collection -- and celebration -- of some the finest purveyors of paleoart. My primary reason in assembling this host of talent was to give them a voice. Generally their work is seen in books running the gamete from children’s to the most serious academic volume; from National Geographic’s website to illustrating a report on a BBC News feature. However, I couldn’t help but notice they rarely got to talk about themselves and their art. I hoped to rectify that and in doing so bring together a collection of amazing art that you don’t need to be a dinosaur enthusiast to enjoy -- although that helps!
Here’s a selection of some of my favorite images, from the book. -- Steve White, editor of Dinosaur Art
I love the lighting on this. What filmmakers call ‘the Magic Hour’ – beautiful twilight colours. It is also preludes the event that heralded the demise of the dinosaurs (and untold other species) – the impact of a massive object, in this case illustrated as an asteroid but possibly a comet or meteor, that slammed into the area of what is now Mexico’s Yucatan Peninsula, unleashing a global catastrophe.
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"As a biologist, seeing this fossil represents something of a pilgrimage," says Bryan, "[Visiting this museum is] a journey that all biologists would benefit from making."
Snip from his blog post:
This particular sample was found in the Solnhofen limestone formation in Bavaria and is the basis for the link between the dinosaurs and the feathered birds. Archaeopteryx itself is a feathered theropod, but is though of as the oldest documented bird dating back approximately 150 million years ago.
The fossil was found in 1874 by Jakob Niemeyer who traded it to Johann Dorr for a cow. Johann then sold the fossil to Ernst Haberlein for 2,000 German Marks. This sale was then turned around to the founder of Siemens, Werner von Siemens for 20,000 German Marks for the University of Berlin which has provided this specimen to scientists around the world as the best preserved specimen found with elegant feathers and an exquisitely preserved skull.