A cautious Camptosaurus approaches a resting Allosaurus. Even though the carnivore undoubtedly hunted the herbivore at times, the two weren’t constantly at war with each other. Art by John Conway, from All Yesterdays.

The dinosaurs I grew up with were both intensely exciting and incredibly dull. They were creatures unlike anything I had ever seen, but their drab, scaly flesh was always fit snugly to their bones with little embellishment. For decades, this has been the paradox of prehistoric restorations. Reconstructed skeletons are gloriously magnificent and introduce us to strange creatures that we never could imagined if we did not already know they existed. Yet the art of reviving these organisms has often been incredibly conservative. Dinosaurs, in particular, have often been “shrink-wrapped”–their skin tightly pulled around a minimalist layer of muscle distributed over the skeleton. This may be part of why dinosaur restorations look so weird. As John Conway, C.M. Kosemen, Darren Naish and Scott Harman argue in their new book All Yesterdays, no living lizard, fish, bird or mammal adheres to such a limited “skin on the bones” fashion. Dinosaurs were not only skeletally distinctive, but they undoubtedly looked stranger and behaved more bizarrely than we have ever imagined. The recently-published Dinosaur Art started to realize these possibilities, but All Yesterdays goes even further in melding science and speculation about dinosaur biology.

On a superficial level, All Yesterdays is a gorgeous collection of speculative artwork. Divided into two sections–the first featuring Mesozoic life in new or little-seen vignettes, and the second imagining how we would restore modern animals if we only had partial skeletons to work from–the book features some of the most wonderful paleoart I’ve ever seen. Scott Hartman’s crisp skeletal reconstructions form the framework from which Conway and Kosemen play with muscle, fat and flesh, and, following Naish’s introductory comments, Kosemen provides scientific commentary about how each illustration is not quite so outlandish as it seems. A curious Camptosaurus approaching an Allosaurus at rest is a reminder that, much like modern animals, prey and predators were not constantly grappling with each other, just as a snoozing rendition of the Tyrannosaurus “Stan” shows that even the scariest dinosaurs had to snooze. The gallery’s feathered dinosaurs are especially effective at demonstrating the fluffy weirdness of the Mesozoic. Conway’s peaceful scene of feather draped Therizinosaurus browsing in a tree grove is the best rendition of the giant herbivore I’ve ever seen, and his fluffy, snowbound Leaellynasaura are unabashedly adorable.

The second half of the book continues the same theme, but in reverse. How would artists draw a cat, an elephant or a baboon if we only had skeletons or bone fragments? And what would those scraps suggest about the biology of long-lost animals? If there are paleontologists in the future, and they have no other source of information about our world, how will they restore the animals alive today? They might have no knowledge of the fur, fat, feathers and other structures that flesh out modern species, creating demonic visions of reptilian cats, eel-like whales and vampire hummingbirds.

Working in concert, the two sections will give casual readers and paleoartists a jolt. While some might gripe about Todd Marshall adding too many spikes and dewlaps to his dinosaurs, or Luis Rey envisioning deinonychosaurs at play, the fact of the matter is that dinosaurs probably had an array of soft tissue structures that made them look far stranger than the toned-down restorations we’re used to. As All Yesterdays presents in various scenes, maybe sauropods liked to play in the mud, perhaps hadrosaurs were chubbier than we ever imagined and, as depicted in one nightmare-inducing panel, Stegosaurus could have had monstrous genitals. None of these scenarios are supported by direct evidence, but they are all within the realm of possibility.

The cover of All Yesterdays, a visual celebration of speculative paleontology.

More than a gallery of speculative art, All Yesterdays is an essential, inspirational guide to any aspiring paleoartist. Those who restore prehistoric life are limited by the evidence at hand, this is true, but “more conservative” does not mean “more accurate.” Using comparisons with modern animals, artists have far more leeway than they have ever exercised in imagining what prehistoric life was like. We’ve seen enough Deinonychus packs tearing apart Tenontosaurus, and far too many malnourished dinosaurs. We need more fat, feathers, accessory adornments and scenes from quieter moments in dinosaur lives that do not involve blood and spilled viscera. Professional paleoartists are beginning to embrace these ideas–Jason Brougham’s recent restoration of Microraptor is an appropriately fluffy, bird-like animal rather than the flying monster Naish and collaborators decry–but All Yesterdays is a concentrated dose of prehistoric possibilities that are being artistically explored.

Some of the book’s restorations may turn out to look quite silly. As lovely as Conway’s rendition is, I still don’t buy the “bison-back” idea for high-spined dinosaurs such as Ouranosaurus. Then again, depending on what we discover in the future, some of the illustrations might seem quite prescient. The important thing is that All Yesterdays demonstrates how to push the boundaries of what we imagine while still drawing on scientific evidence. The book is a rare treat in that each section explicitly lays the inspiration for each speculative vision, providing references for those who want to dig deeper.

If anything, All Yesterdays shows that we should not be afraid of imagination in science. Even though we know far more about dinosaur biology and anatomy than ever before, there are still substantial gaps in our understanding. In these places, where bones might not have much to tell us, science meets speculation. The result is not anything-goes garishness, but an exploration of possibilities. Somewhere within that murky range of alternatives, we may start to approach what dinosaurs were truly like.

You can purchase All Yesterdays in any of its various formats here.

Seeing a hadrosaur alive would be a fantastic sight. Or any non-avian dinosaur, for that matter. As lovely as today’s avian dinosaurs are, it’s their distant, extinct cousins that fire my imagination. Sadly, despite the speculations of theoretical physicist Michio Kaku, I don’t think my dinosaur dreams are going to come true.

In a Big Think video posted last week, Kaku rhapsodized about the possibility of resurrecting extinct species through genetic techniques. I’m not as optimistic as he is, especially since Kaku glosses over some essential steps in his confused editorial.

Kaku spends most of the video talking about Neanderthals and woolly mammoths. These species went extinct so recently that, in some cases, researchers can extract DNA from their remains and go about reconstructing their genomes. Pretty cool science. Whether I’ll ever be able to cuddle a fuzzy baby woolly mammoth is another matter. (I’ve heard promises ever since I was a child. I’m still waiting.) But non-avian dinosaurs obviously present a different problem. They went extinct about 66 million years ago, and, given the circumstances required for genetic preservation, there’s no hope of ever obtaining Mesozoic dinosaur DNA.

But, Kaku says, “we have soft tissue from the dinosaurs.” He makes it sound as if dinosaur skeletons are saturated with bits of prehistoric flesh. “If you take a hadrosaur and crack open the thigh bones, bingo,” he says, “You find soft tissue right there in the bone marrow.”

Kaku’s going far afield from what science has actually revealed. Since 2007, paleontologists and molecular biologists have been tussling over the possibility that some non-avian dinosaur fossils might preserved the degraded remnants of soft tissue structures such as blood vessels. A Tyrannosaurus femur kicked off the debate, which has since extended to the hadrosaur Brachylophosaurus, as well.

Even though researchers Mary Schweitzer, John Asara and colleagues have hypothesized that they’ve detected preserved proteins from remnants of dinosaur soft tissues, their results have been heavily criticized. The supposed dinosaur leftovers may be microfossils created by bacterial biofilms that broke down the creature’s bodies, and the protein analysis–which placed the supposed T. rex protein close to bird protein–might have suffered from contamination. As yet, there’s no definitive proof that non-avian dinosaur soft tissues or proteins have actually been recovered, and the debate is set to go on for years to come. Contrary to what Kaku says, you can’t simply break open a dinosaur skeleton and start scooping out marrow.

Not that preserved protein would bring us closer to resurrecting Tyrannosaurus or Brachylophosaurus, anyway. The biomolecules could tell us a bit about dinosaur biology, and possibly become another way to test evolutionary relationships, but we’d still lack dinosaur DNA. And even if we could reconstruct a dinosaur’s genome, that doesn’t mean that we could easily clone one. Much like Michael Crichton before him, Kaku skips over an essential and complicated step–the development of the embryo inside the mother. How do you go from a genetic map to a viable embryo? And how can we account for interactions between the embryo and the surrogate mother–a member of a different, living species–that could influence the experimental animal’s development?

Studying the genetics and biomolecular makeup of prehistoric organisms is a fascinating area of research. And even though the dinosaur protein issue remains contentious, the debate has the potential to refine a new way to look at dinosaurs. That’s where the real value of this science is. Non-avian dinosaurs are long gone, and I don’t believe that we’ll ever be able to bring them back to life. But the more we understand about their biology, the better we can reconstruct dinosaurs in our scientific imagination.

Richard Milner's 'Charles R. Knight: The Artist Who Saw Through Time.'

There has never been a more influential paleoartist than Charles R. Knight. He wasn’t the first to illustrate prehistoric life, and he certainly was not the last to do so with great skill, but, for a time, he envisioned dinosaurs and other ancient creatures with such loving detail that he seemed to be sending back snapshots from lost eras only he could visit.

Science writer Richard Milner recounted Knight’s story in his visual and textual mix-tape of the artist’s work, Charles R. Knight: The Artist Who Saw Through Time. The book is not a straight biography. Even though Milner composed a detailed summary of Knight’s life for the book’s introductory section, the bulk of the glossy volume is a showroom of Knight’s art and quotes from his books and articles. A set of closing chapters covers Knight’s legacy, from efforts to restore cracking murals to the artist’s dream of a scientifically accurate dinosaur theme park, but the greater portion of the volume is a portfolio of Knight’s range and skill.

I did not know much about Knight before reading Milner’s biographical section. I imagined that Knight was simply a passionate observer of nature who committed his imagination to canvas and paper. As Milner ably demonstrates, Knight’s cherished body of work is the fruit of multiple struggles, both physical and vocational, from the time of his birth in 1874. Born with severe nearsightedness, a playtime accident when Knight was a young boy virtually robbed him of sight in his right eye. His vision continued to deteriorate during his entire life. Knight was legally blind by the end of his career, and he had to hold his face only inches from the canvas to see what he was painting.

Knight was also a finicky and often cantankerous artist who had a difficult relationship with his primary sponsor, the American Museum of Natural History. Although Knight’s initial love was illustrating living animals—he designed a bison for a 30 cent stamp and created sculptured visages of animals for the Bronx Zoo that can still be seen on some of the old buildings—in 1894 he was asked to restore the fossil mammal Entelodon for AMNH scientist Jacob Wortman. Wortman and his colleagues were thrilled with the result. It was a triumph for Knight, who had learned a great deal of anatomy from taxidermists at the museum, and paleontologist Henry Fairfield Osborn desperately wanted Knight to be the museum’s chief restorer of prehistoric creatures.

Neither Knight nor Osborn were easy men to work with. Knight refused to have collaborators and rejected almost all criticism. He wanted to hear only scientific corrections from Osborn, and he frequently argued with Osborn about critiques others made of his paintings. And, despite Osborn’s wishes, Knight repeatedly refused to become a museum employee. He wanted to stay a freelance artist, and this created new problems. Osborn had to raise additional funding for Knight’s work, and to do this he often wanted sketches or samples to convince patrons. Knight, however, would not budge on the work until funding was secured and his terms regarding criticism were agreed upon. Knight needed Osborn because the artist was almost perpetually broke or in debt due to poor money handling, and Osborn needed Knight because there was no finer animal artist anywhere. This was a tense alliance that almost completely broke down when Knight created a series of prehistoric murals for the better-funded Field Museum—a project similar to one Osborn had been planning to execute with Knight for the AMNH dinosaur halls. Still, the two eventually overcome their pride and remained friends, albeit ones frequently frustrated by each other.

Knight also showed off his cantankerous nature in numerous editorials. He hated news and magazine articles that made animals seem overly cute or especially vicious, although Knight probably reserved most of his hatred for modern art. Knight loathed the popularity of artists such as Henri Matisse and Pablo Picasso. Knight thought their works were “monstrous and inexplicable creations masquerading in the name of art.” Matisse, according to Knight, couldn’t even accurately draw a bird. Knight believed that the modern art movement was primarily the product of savvy art dealers and advertisers. There was a bit of sour grapes about this. As modern art gained in popularity, Knight had an increasingly difficult time selling his own work. People were just not interested in realistic paintings of animals.

Knight’s successes were hard-won, but, as Milner’s biography illustrates, the artist could not have done anything else. Knight’s undeniable passion was painting prehistory into life. A few snippets in the book provide some insights into Knight’s process. For dinosaurs, at least, Knight would often study the mounted skeletons of the animals and then, on the basis of this framework, create a sculpture. He could then study this three-dimensional representation for the play of shadow across the body under different conditions, and from this model Knight would then begin painting. In the case of his murals, though, Knight designed the art but did not paint the actual, full-size pieces himself as Rudolph Zallinger did with the Age of Reptiles. Instead, Knight created a smaller version of the mural which was then expanded according to a grid system by painters. Knight added only touch-up details to the murals.

Those murals and various other paintings continued to inspire artists and scientists after Knight’s death in 1953. After seeing images of absolutely atrocious, cut-rate dinosaur sculptures at a park in South Dakota, Knight wanted to create his own, scientifically accurate garden of dinosaurs and appropriate, Mesozoic-type flora somewhere in Florida. Knight never attracted the investors necessary to create the park, but the idea was carried on by his friend Louis Paul Jones in the form of Sinclair Dinoland at the 1964 World’s Fair in New York. Likewise, Knight’s cutting comments about prehistoric mammal sculptures at the La Brea asphalt seeps in Los Angeles led the institution to eventually commission new, better sculptures after Knight’s style. Even ripoffs of Knight’s work influenced culture. When Arthur Conan Doyle’s The Lost World initially ran in serial form, illustrations based heavily on Knight’s paintings accompanied the text, and the film version of the story featured a now-defunct horned dinosaur genus, Agathaumas, that was clearly based on a painting Knight created with some tips from an ailing Edward Drinker Cope.

Knight was a brilliant and taciturn artist. He constantly battled his boss, artistic society and his own eyesight to create intricate scenes inspired by old bones. In doing so, he elevated realistic, scientific representations of life through the ages into a lovely artistic hybrid. Even as new discoveries about dinosaurs, prehistoric mammals, and other creatures make some of Knight’s illustrations seem dated, his paintings still carry the reflection of someone who joyfully reveled in the story of life.

Just a small part of the huge bonebed which is Dinosaur National Monument's quarry wall. Photo by the author.

Two summers ago, I visited Dinosaur National Monument for the first time. The park was one of the most beautiful places I had ever seen, but, I have to admit, I left a little disappointed. Ever since I was a dinosaur-crazed kid I wanted to see the famous quarry wall strewn with hundreds of bones representing some of the most famous Late Jurassic dinosaurs. But when I arrived, the building that housed the bones had already been closed for three years. The geology of the site worked against the edifice by expanding and contracting by minute amounts over and over again—so much so that parts of the building had shifted dramatically and put the entire structure at risk of collapse.

Not long before my initial visit, though, it was announced that the park would receive more than $13 million to restore the building and welcome visitors once more. I couldn’t wait for the grand re-opening, especially after I spent more than a week and a half looking for new fossils at the monument with the Natural History Museum of Utah field crew this past summer. I saw the quarry building from the road every day I was in the field, but I had to wait until October 4, 2011 for the doors of the quarry to once again open to the public.

As it stands now, the famous quarry wall is only a portion of what once was. The site once extended about 100 feet to either side of the current quarry face, and the bonebed also extended upwards to a higher hill that paleontologist Earl Douglass and his co-workers removed during the early 20th century. Many of the fossils they discovered in those parts of the quarry can now be seen at museums such as the Carnegie Museum of Natural History in Pittsburgh. (Those old bones were recently refurbished in a new dinosaurs exhibit I got to see during last year’s SVP conference.) Nevertheless, the quarry face is still a beautiful site. Partially articulated limbs, a sauropod skull situated on the end of a vertebral string, parts of various spinal columns and numerous isolated bones can be seen poking out all over the rock face. That’s how they will remain—prep work has stopped on the fossils, and they will stay in their place as a lesson about life and death 149 million years ago.

An Allosaurus munches on a baby Stegosaurus in the new DNM mural created by Bob Walters and Tess Kissinger. Photo by the author.

The bones are the main draw, of course, but the new museum also boasts some impressive extras. Several skeleton casts on the lower level introduce visitors to some of the charismatic creatures seen scattered over the quarry wall, and a beautiful mural by artists Bob Walters and Tess Kissinger fleshes out Late Jurassic dinosaurs such as Stegosaurus, Torvosaurus, Dryosaurus and Apatosaurus, in addition to the many small mammals and reptiles that lived alongside them. Make sure you turn around to look at the mural behind the baby Stegosaurus cast when leaving the building—I don’t think I have ever seen an illustration of an Allosaurus chomping down on a baby Stegosaurus before.

More updates and improvements are scheduled but were not ready at the time of the big unveiling. The museum will include virtual displays that will explain how so many dinosaurs came to be accumulated in one spot, as well as what bones on the quarry wall correspond to which dinosaurs. Even without those extras, though, the new quarry wall is a fantastic testament to deep time, evolution and a lost world we are still striving to understand.

For more details about Dinosaur National Monument, see the Dinosaur National Monument Quarry Visitor Center Project blog. The blog is written by Dan Chure, the park’s paleontologist.

The Second Jurassic Dinosaur Rush by Paul Brinkman.

Many visitors to natural history museums—especially children—come to see just one thing: dinosaurs. No major institution can be without a hall of enormous Jurassic and Cretaceous animals (with the smaller, lesser-known Triassic dinosaurs taking their places along the margins), but the American occupation with the biggest and baddest Mesozoic creatures is relatively new. Even though dinosaurs captured the public’s imagination relatively early on —appearing in cartoons, poetry and other bits of pop culture in the 1820′s—they were still almost entirely absent from American museums at the close of the 19th century. Even at the height of the infamous “Bone Wars” between the academics O.C. Marsh and E.D. Cope, public museum displays typically boasted little more than a few teeth and a limb bone or two.

As historian and paleontologist Paul Brinkman illustrates in his new book, The Second Jurassic Dinosaur Rush, today’s spectacular dinosaur displays have their roots in the turn-of-the-20th-century contest to see who could obtain the most impressive sauropod dinosaur. The American Museum of Natural History, the Carnegie Museum and the Field Museum competed to find the most complete Jurassic dinosaur specimens possible (skeletons that are still prominently on display in each institution to this day), yet this second “dinosaur rush” was a bit different from the rough-and-tumble expeditions of Cope and Marsh. Rather than actively try to savage one another’s reputation, teams from each of the institutions tried to lure away members of opposing groups and kept a watchful eye on what their competitors were doing, with whatever controversies erupted being a result of museum politics instead of Wild West antics. They did not always get along, but they had common goals, and so many of the paleontologists working at that time hated Marsh that each team was trying to find its own way of showing that America’s former leading paleontologist was not as brilliant as he thought he was.

Much of Brinkman’s book records the movements and activities of the paleontologists employed by the various museums as they scouted Jurassic-age dinosaur sites in the American West. There are quite a few famous names to keep track of —H.F. Osborn, John Bell Hatcher, William Diller Matthew, Barnum Brown, Elmer Riggs, Olaf Peterson, J.L. Wortman and others—and a number of them switched institutions during the period in question. At times it is easy to get confused about who was working for whom, but this is less the fault of Brinkman’s clear prose than of the politics and dealings of early-20th-century paleontologists.

Although I would have preferred a little more analysis of how discoveries in the field were translated into academic and popular images of dinosaurs—something discussed primarily in the conclusion, in relation to the role of paleontology in large museums—Brinkman’s work fills in a considerable gap in our understanding of the history of paleontology. Every paleontologist worth his or her salt is familiar with the names Osborn, Hatcher, Riggs and the like, but few have paid much attention to the details of how these researchers collected specimens and kept paleontology thriving during a time when their discipline was being superseded by genetics and other biological sciences in universities. Had large museums not been so interested in fostering their paleontology programs—programs with great potential to collect specimens that would bring in hordes of patrons—the science may very well have stagnated. Although paleontologists sometimes found themselves caught up in red tape or working for finicky institutional administrators, both museums and paleontology benefited from the close collaboration.

If I have any significant criticism of Brinkman’s work, it is that the book should have included a glossary or appendix explaining the present nomenclature for many of the dinosaurs discussed in the book. Frequent references are made to the sauropod Morosaurus, for example, which was considered a valid name at the turn of the 20th century but has since been synonymized with Camarasaurus. Those steeped in the esoterica of dinosaur paleontology will have no problem with such details, but other readers may be puzzled to see so many unfamiliar dinosaur names.

[Editor's Note: We have been informed by the author that an appendix on dinosaur classification IS included in the final copy. Our apologies for the mix-up and confusion.]

There are a few major gaps in the history of paleontology that, for one reason or another, have not yet merited a major investigation. Brinkman’s The Second Jurassic Dinosaur Rush has now filled in one of those gaps in a comprehensive and accessible manner. From daily camp life to museum politics, Brinkman has ably documented a time of major change in dinosaur science, one that provides the context for paleontology as we know it today.

A cross section of a generalized limb bone denoting the different structures. Fossil bone often preserves these internal structures, too. From Wikipedia.

When I was a child, one of my uncles gave me what he said was a real dinosaur bone. The little black object certainly looked like some sort of bone, and I kept it in my little collection of shark teeth and other fossils in my closest. After a while I almost completely forgot about it, but when I took a college course on dinosaurs I remembered the little thing. I took it to my professor to ask what kind of animal it might have come from.

It was not a fossil at all, my professor told me. The “dinosaur bone” was really a concretion, or a small lump of mineral that had formed around some bit of detritus. A broken part of the object made the identification easy. The exposed internal structure was compact, uniform, and smooth. It entirely lacked any sign of internal bone structure that a real dinosaur bone would exhibit.

Paleontologists respond to dozens of similar queries each year. Many people find concretions or vaguely bone-shaped rocks and bring them in to ask what kind of dinosaur the “bones” came from and if the museum would be interested in buying them. Needless to say, most of those people leave a bit disappointed that they have not uncovered the find of the century in their backyard, but these common experiences bring up a simple question: how can you tell fossil bone from stone?

There is no single hard-and-fast rule for distinguishing rock from bone, but there are a few principles that can definitely help you tell the difference. One of the simplest is that you need to know where to look for fossils. If you spot a “dinosaur egg” in the soil while mowing your lawn the chances are pretty good that is is just a rock. Real fossils will be found in particular rock formations which geological maps and even some state-specific booklets can help you identify. Before you grab your pick and shovel, though, you will have to familiarize yourself with the type of land those deposits are on and what the rules are about collecting fossils. If you just walk to a formation and pick out a fossil without filling out the right paperwork and being absolutely certain of where you are, you are probably breaking the law (not to mention the fact that trained paleontologists are much better qualified at properly documenting and excavating fossil sites).

But let’s assume that, regardless of how it was acquired, you have what you think is a piece of fossil bone. Out of its geologic context it is impossible to compare it to the surrounding rock (fossils are often different in color and smoother than rocks from the same deposit), but if there is a break on the specimen you may be able to check its internal structure. A rock or concretion, like the one I showed to my professor, will be solid, and the inside of the rock will look like the outside. Fossil bone, on the other hand, will probably preserve the internal bone structure. In a fossil bone you will be able to see the different canals and webbed structure of the bone, sure signs that the object was of biological origin. You can even try a tongue test. The porous nature of some fossil bones will cause it to slightly stick to your tongue if you lick it, though you might want to have a glass of water handy if you feel compelled to try this.

By following these guidelines it becomes easier to determine whether or not you have really found a fossil bone. It does not take a Ph.D. education; just some attention to detail and common sense.

The skeleton of Sinosauropteryx, complete with preserved feathers. From Wikipedia.

At one point or another, almost every general book about dinosaurs I have ever seen has said the same thing: we cannot know what color dinosaurs were. Scientists have found the skin impressions of some specimens, but as far as we know these traces contain nothing that might tell us what color those dinosaurs were. As described in this week’s issue of the journal Nature, however, scientists have been developing a technique that may allow us to see the colors displayed by some dinosaurs, and it is thanks to their connection with birds.

Last year the journal Biology Letters published the results of a study that identified preserved microstructures related to color in the feather of a fossil bird. The scientists could not say for sure what colors the feather exhibited in life, but they were able to document minute differences in the feather that are seen in living birds, meaning that evidence of color was preserved in the fossil even if it could not be fully understood yet. Now a different team of scientists has published a new study that has accomplished a similar task, but this time for two feathered dinosaurs and one of their bird relatives.

What the scientists behind the Nature study were looking for were melanosomes. These are color-carrying structures found inside pigment cells and are partially responsible for the colors we see in many organisms. The paleontologists found them in abundance in the feathers of the dinosaurs Sinosauropteryx and Sinonithosaurus, as well is in the preserved plumage of Confuciusornis. The structures were not preserved bacteria or some other remnant. Instead they were the preserved vestiges of dinosaur cell structure.

Clearly these animals had color-carrying cells in their feathers, but what color were they? That is a more difficult question to answer. The fossils that were examined contained two types of melanosomes: eumelanosomes and phaeomelanosomes. From the study of living organisms we know that eumelanosomes are associated with dark colors (i.e. black) while phaeomelanosomes are associated with lighter colors (i.e. yellowish to red). They cannot tell us specifically what color the dinosaurs were, but they can help us confirm color patterns and be used create hypotheses. The tail of Sinosauropteryx, for example, contains  bands of feathers stuffed with phaeomelanosomes, and so the authors of the new paper suggest that it might have had bands of rich, reddish tail feathers. This hypothesis will require more evidence to confirm, however, especially since scientists are still learning how melanosomes are involved in producing particular colors.

The new research is a step closer to understanding what colors some dinosaurs were, and it is another piece of evidence confirming that the structures preserved around dinosaurs like Sinosauropteryx and Sinornithosaurus really are feathers. The melanosomes are contained entirely inside the feathers, just like in living birds, and there no longer can be any reasonable doubt that these animals were feathered dinosaurs. Even better, this line of inquiry has only just begun, and perhaps in a few years we will be able to tell with greater certainty whether dinosaurs were as colorful as their living relatives.

Zhang, F., Kearns, S., Orr, P., Benton, M., Zhou, Z., Johnson, D., Xu, X., & Wang, X. (2010). Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds Nature DOI: 10.1038/nature08740

Portrait of Mary Anning (via wikimedia commons)

We don’t usually give much thought to who discovered a fossil. Museums rarely include much more information than species name and the state or country where the remains were found.

The exception, in several museums in England at least, is fossils found by Mary Anning in the early 19th century. And two new books, one biography and one novel, bring her story to life.

Mary was born in 1799 in Lyme Regis, on the southern coast of England. Her father was a cabinetmaker who preferred to hunt for fossils, but neither occupation brought the family much money. When he died in 1810, he left behind a pregnant wife, two children and a large debt. Mary and her brother took to fossil hunting for survival.

Her brother found what he thought was a crocodile head in 1811 and charged Mary with removing it from the rock and searching for the rest of the skeleton. (Mary often gets credit for the discovery, though that is not technically correct.) She eventually dug out the skull and 60 vertebrae, selling them to a private collector for the handsome sum of £23. But it was no common crocodile. It was an Ichthyosaurus, a “fish-lizard,” and the first of many amazing finds.

A plesiosaur, Rhomaleosaurus cramptoni, found by Mary Anning and on display in London's Natural History Museum (via wikimedia commons)

Mary’s brother would become an upholsterer, leaving fossil hunting to his sister. She would become one of the most prolific fossil hunters of the time, discovering more ichthyosaurs along with long-necked plesiosaurs, a pterodactyl and hundreds, perhaps thousands, of other fossils.

Though she had little formal education, Mary taught herself geology, paleontology, anatomy and scientific illustration. She corresponded with, provided fossils for and sometimes hunted with well-known scientists of the time, such as William Buckland and Richard Owen (who would coin the word “dinosaur” in 1842). Her finds were key to the reconstruction of Earth’s past and the development of the theory of evolution (as well as the development of several scientists’ careers).

But Mary never published a scientific paper of her own—men wrote up her finds. Even if she had written one, it was unlikely that it would have been published because she was female. Mary was never wealthy. Until a friend convinced the British Association for the Advancement of Science to provide her with an annuity of £25 per year, she was always one accident away from total destitution. And though the Geological Society marked her 1847 death from breast cancer a year later in a president’s address (a rare honor), the organization didn’t admit its first female member until 1904. Even today many of her finds will never be associated with her name, the records lost long ago.

Mary is now emerging from history. The Natural History Museum in London, for instance, has made her and her finds the main attraction of their Fossil Marine Reptiles gallery. The Lyme Regis Museum stands on the site of her birth. She is the subject of several children’s books. And the Geological Society has placed one of her ichthyosaur skulls and a portrait of her and her dog in their front reception hall.

A new biography, The Fossil Hunter by journalist Shelley Emling, tells Mary’s story in detail for the first time. The book is detailed and well researched, drawing on Mary’s own diaries when possible. And the story is captivating enough to forgive Emling for the slightly annoying habit of reconstructing her subject’s hypothetical thoughts and feelings.

Mary truly comes alive, though, in a novel published today: Remarkable Creatures, by Tracy Chevalier, author of Girl With a Pearl Earring. Chevalier imagines Mary’s life into her twenties, told through both her own point of view and that of a friend, the older Elizabeth Philpot. There are conceivable explanations for mysteries of Mary’s life, such as why she never married and how one collector comes to sell all of his fossils and give the proceeds to Mary and her family. Chevalier knows how to tell a good tale, and her story of Mary is definitely that.

A restoration of Aardonyx. From the Proceedings of the Royal Society B paper.

The sauropod dinosaurs were the largest animals to have ever walked on the earth. They were so incredibly huge, in fact, that they had to move about on four legs—but since the earliest dinosaurs were bipedal, paleontologists have long known that the ancestors of giants like Brachiosaurus and Apatosaurus actually trotted about on two legs. A dinosaur just described in the Proceedings of the Royal Society B sat close to this major transition in sauropod evolution.

Recovered from Early Jurassic (about 183 – 200 million year old) rock in South Africa, Aardonyx celestae was an approximately 20-foot-long dinosaur that combined elements that are both strange and familiar. It had a small head, a long neck, a large body, and a long tail, but it still had relatively short forelimbs compared to its hind legs. While it could occasionally walk on four legs, its limbs indicate that it primarily walked around on two , and an evolutionary analysis that was part of the new study placed it relatively close to the earliest sauropod dinosaurs (thus fitting Aardonyx within the larger category of dinosaurs called sauropodomorphs).

Aardonyx was not actually ancestral to the larger,  four-feet-on-the-floor sauropods—it lived during a time when such dinosaurs already existed—but it preserves some of the transitional features that we would expect to find in the actual ancestor. (Contrary to a headline published by the BBC, it is not a “missing link” and the entire concept of “missing links” is a hopelessly out-of-date idea that was discarded by scientists long ago. The phrase goes back to a time when life was viewed as proceeding from “lower” forms to “higher” ones in a straight line, and scientists have rightly rejected it in favor of a branching bush of evolutionary diversity.)

While not a direct ancestor of dinosaurs like Diplodocus, this new dinosaur will help us better understand how sauropod dinosaurs evolved. If you would like to know more about it check out the blog of the lead author of the new description, Adam Yates, where he summarizes the important details about Aardonyx. It is good to see working paleontologists take a more active role in communicating their discoveries to the public, and I hope that other dinosaur specialists will follow the example made by Yates and others.

The exceptionally-preserved skeleton of Darwinius. From PLoS One.

This week news services were all a-twitter about a 47-million-year-old fossil primate from the famous Messel deposits of Germany. Named Darwinius masillae and described in the journal PLoS One, the lemur-like primate was heralded as being a transitional form between a group of extinct primates called adapids and anthropoid primates (monkeys and apes). As it turns out the fossil may not be all it has been cracked up to be, but it is still a spectacular find that represents one branch of the primate radiation that occurred after the mass extinction that killed off the dinosaurs at the end of the Cretaceous. Creatures like Tyrannosaurus perished, but primates survived.

Tracing the record of the earliest primates is a challenge. Since primates started off small and lived in forested habitats their fossils are extremely rare, and most fossils that are found are teeth. This can make comparisons between these creatures difficult, and the relationships among early primates or primate-like creatures are controversial. The fact that some molecular studies places the origin of primates even further back in the Cretaceous, about 85 million years ago, makes things even more complicated as no verifiable primate fossils have yet been found from that age. Despite these complexities, however, scientists do have a broad outline of early primate evolution.

One of the earliest primate-like creatures was Purgatorius, a tree-shrew-like mammal that lived right around the end of the Cretaceous 65 million years ago. Whether it was one of the first primates or only closely related to the first primates is still controversial, but it does seem to represent what the ancestors of primates were like during the time that dinosaurs were the dominant land-dwelling vertebrates.

After the mass extinction, mammalian evolution exploded. Mammals were no longer under the feet of dinosaurs, and among the groups that diversified were primate-like creatures called plesiadapiformes. Whether these creatures were true primates or just very primate-like is still being debated, but they underwent a boom and bust during the Paleocene (about 65 to 55 million years ago). In many ways these creatures were somewhat squirrel-like, with clawed hands and eyes on the sides of their heads, but at the very least they seem to be the closest extinct relatives to other primates.

The creatures that are regarded as “true” primates flourished during the Eocene (about 55 to 33 million years ago), and can largely be placed into two groups: the adapids and omomyids. The adapids were lemur-like primates, while the omomyids closely resembled living tarsiers, but both had forward-oriented eyes and adaptations to life in the trees. Both these groups are relevant to yesterday’s big announcement.

According to the new paper, Darwinius is an adapid, and many scientists presently regard this group as being more closely related to modern lemurs and lorises than to monkeys or apes. Many paleontologists who study extinct primates favor omomyids and ancient tarsiers as being closer to monkeys and apes, but the authors of the new paper don’t think so. In the paper itself they claim that Darwinius belongs to the same large group of primates, haplorrhines, as tarsiers, monkeys, and apes, thus placing adapids in a position to potentially become our ancestors. This conclusion has caused the scientists involved in the study and the popular media to herald it as a “missing link” that connects us to other primates.

Unfortunately, however, the scientists who wrote the paper did not conduct a detailed evolutionary analysis of the new fossil or its relationships to other primates. The fossil is spectacular, the first fossil primate to be find in such a state of exceptional preservation, but it has been oversold by the History Channel (who organized the media hype) and the scientists involved in the study. They simply did not do the work to support the conclusions they drew from the fossil, and the real relationship of Darwinius to other primates will have to wait for further studies.

A pair of Iguanodon on a riverbank, from Current Literature.

Outside of Hollywood films, dinosaurs like Tyrannosaurus and Triceratops never coexisted with humans, and no case can be made that The Flintstones is an accurate depiction of prehistory. That has not stopped young-earth creationists from maintaining otherwise, though, and this has led to some rather silly statements.

Attempts to squeeze paleontology into a literal interpretation of Biblical timelines have a long history. A 1912 issue of Current Literature featured some excerpts from a book about paleontology called Evolution in the Past by H.R. Knipe. The article itself is not terribly interesting, but the captions accompanying the article’s illustrations are. Several dinosaurs and extinct mammals are featured and each caption explains the benefits or dangers these animals would have posed to early humans. The caption beneath a pair of Iguanodon reads:

THE TERROR OF THE RIVERBANK IN THE GEOLOGICAL PAST

The iguanodonts [sic] fought with their tails, and in the course of the combat rendered life precarious in the vicinity for all living creatures. It is difficult to see how prehistoric man could have made his abode along the main streams while these monsters flourished.

In truth, early humans had nothing to fear from Iguanodon. The herbivorous dinosaurs had been extinct for about 114 million years by time the earliest humans evolved in Africa. To suggest otherwise would require some startling evidence indeed! It should be noted that the tone of some of the captions makes it seem like they are not to be taken seriously, but even if this is true they are not out of line with what many creationists truly believe. (Don’t even get me started on their ideas about what Tyrannosaurus would have eaten in the Garden of Eden.)

If humans did live alongside dinosaurs, though, it does raise the question of how our kind survived. Why wouldn’t our species have been consumed by a horde of hungry tyrannosaurs, or our early attempts at agriculture destroyed by herds of sauropods? There is simply no record of any kind of Dinotopia, and most of the “evidence” creationists offer are like Rorschach tests; they see what they want to see. Watching humans flee from dinosaurs might make for exciting cinema, but it is absolutely awful history.

A few months ago my colleague Mark Strauss mentioned the controversy surrounding the state dinosaur of Texas. Previously the state’s patron dinosaur was the sauropod Pleurocoelus, but this has turned out to be a mistake. Pleurocoelus was initially named for bones found in Maryland and the same name was applied to fossils from Texas. As it turns out, however, the Texas bones are distinct enough to merit a different genus name, Paluxysaurus.

The change should have been relatively simple. Texas was not really getting a new dinosaur; the name of the fossils were just being changed. Things got complicated, however, when ten-year-old Shashwatch Murphy petitioned to have the state dinosaur changed to Technosaurus. It was a valiant effort, but unfortunately for Murphy, Technosaurus was actually not a dinosaur at all and could not be considered for the honor of state dinosaur.

Paluxysaurus looked like a shoe-in for the “new” state dinosaur, but the Texas representatives decided to use the opportunity to engage in a little legislative theater. Some of the primary supporters of the resolution, like representatives Mike Hamilton and Mark Homer, put on dinosaur suits to show their support for the name change (even if Hamilton mixed up the words “extinct” and “instinct”). Some of the other representatives gave them a hard time, though. Representative Dan Gattis made known his opposition to the bill as “In accordance with the international fourth-grade spelling bee and grammar rules … the author [of the bill] cannot even spell or pronounce all the words in his resolution.”

If Gattis opposed the bill, he was the only one. The measure passed by a vote of 132 to 1 (even though it still has to pass through the state senate). Unless there are any more shenanigans to be played out, it looks like Paluxysaurus is the new state dinosaur of Texas.

A skeleton of Gorgosaurus. From Wikipedia.

It may never be possible to create a real-life Jurassic Park, but if I were given the task of picking which dinosaurs to bring back to life, there are a few that would be at the top of my list. I would love to be able to see all dinosaurs in the flesh, of course, but here are five (in no particular order) that I would like to see more than most any others.

1) Amargasaurus

The first time I heard about it I almost couldn’t believe it. A sauropod with sails on its neck? It might sound like a fantasy cooked up by an over-imaginative paleontologist, but the early Cretaceous sauropod Amargasaurus really did have two parallel rows of long spines on its neck. The question is whether these spines were “naked” or carried sails, and something that is difficult to figure out without seeing the living animal.

2) Epidexipteryx

This is a “new” dinosaur, having been described only in October of 2008, but it is one of the most bizarre. It was a small, feathered theropod with a set of teeth organized into a scoop, and four long feathers sticking out of its stumpy tail. As strange as it was, though, it may be one of the dinosaurs most closely related to birds, and has the potential to shake up current hypotheses about bird evolution.

3) Gorgosaurus

Gorgosaurus might not be as strange as the previous two dinosaurs, but I do have a soft spot in my heart for it. One of the first dinosaur skeletons I ever saw was the Gorgosaurus mount at the American Museum of Natural History, and this tyrannosaurid has been a favorite of mine ever since. It might not be as famous as its cousin Tyrannosaurus, but it was a much sleeker animal. It would probably be best to view this one from a distance, though.

4) Baryonyx

I know this list is getting a little theropod-heavy, but it is hard to resist Baryonyx. At the time it was discovered it represented a new kind of predatory dinosaur with heavy forelimb claws and a crocodile-like snout. Its relative Spinosaurus was discovered first, but it was only when Baryonyx was found that some previously enigmatic theropod fossils began to make sense. Given that it was probably a fish-eater, it might be a little safer to observe, too.

5) Pachyrhinosaurus

Horned dinosaurs were my favorites when I was a kid, and none seemed as odd as Pachyrhinosaurus. With the huge flattened bosses of bone, it stood out against more familiar forms like Triceratops, and there seemed to be a vigorous debate over whether it had a huge nose horn or a more flattened nose ornament. It seems that the latter hypothesis is more likely, but it still would have been an impressive creature to see!

There are plenty of other dinosaurs I would like to see, but these five are among my favortes. What are yours?

The cover of Fantastic Four #345. From Cover Browser.

I was cleaning out some old boxes yesterday when I happened upon dinosaurs in an unexpected place. A few years ago a cousin of mine gave me all of his old comic books, most of which wound up in a box for safe keeping. When I dug up the dusty old container yesterday, I noticed that some of Marvel’s most famous superheros once fought dinosaurs.

The 345th issue of Fantastic Four might have held a shock for fans of the super-powered team. On the cover of this issue was a Triceratops draped in the torn suits of Mr. Fantastic, the Invisible Woman, the Human Torch, and the Thing with the words “Fantastic Four No More!” Could a herbivorous dinosaur really have been the end of the heroes?

As you might expect, the answer is “no.” Due to a time travel glitch, the Fantastic Four wound up on a mysterious island where American soldiers were already battling it out with dinosaurs. (Gee, that’s an original idea.) The superheros and the soldiers manage to evade the dinosaurs with few casualties, but in order to distract a rampaging Triceratops Mr. Fantastic has to strip to his skivvies. Thankfully he is provided with an extra uniform soon afterwards.

The next issue, #346, picks up the storyline. After fending off a Tyrannosaurus the survivors head out to sea on a wooden raft, and as is comic book convention there is something hungry waiting in the water. Somehow the humans manage to fend off the Kronosaurus and make it back to their own time. I am a little weary of the “dinosaurs on a mysterious island” storyline, though. Why can’t someone think of something a little more original, like “Dinosaurs on a Plane“?

A child poses next to the skeleton of a hadrosauroid dinosaur. From Flickr user Clover 1.

Time is running out for paleontologists studying a Cretaceous fossil site in North Arlington, Texas. As reported by CBS 11, paleontologists from the University of Texas only have about five months to finish their work before they will have to make way for a huge development project. This is unfortunate, especially because the site may hold the remains of a mystery dinosaur.

The 1,700-acre site was discovered in 2003 by Art Sahlstein and his daughter Olivia. It seemed like a promising place to dig, conveniently placed for University of Texas students, but it took about four years before paleontologists received permission to excavate. When they were finally able to search the locality, the paleontologists found that most of the bones belonged to a hadrosauroid dinosaur, perhaps Protohadros. They have yet to find a skull, however, and researchers working the site have stated that finding one is essential to knowing whether these dinosaurs were Protohadros or something new. They only have the summer to find out.