How Sue Died

Photo by mharrsch, via flickr

If you've seen Sue, you may have seen those holes on her jaw (as shown above) and wondered what caused them. While they superficially look like bite marks, they have been attributed to a bacterial infection called Actinomyces. But a new study led by Ewan D. S. Wolff of the University of Wisconsin and published by PLos ONE arrives at a new, intriguing conclusion: The holes are caused by a disease similar to one called Trichomonas which is found in modern birds.

This story has a couple of interesting aspects to me. First, it's another piece of circumstantial evidence linking dinosaurs and birds - the authors believe that the parasite that causes the disease may be an ancestor of the one that infects modern birds. Second, the authors note that it sheds further light into the behavior of the Tyrannosaur clan. From the paper:

Given the ways in which Trichomonas infection is spread among extant birds, the occurrence of a similar disease in tyrannosaurids suggests five possible scenarios for transmission: water-borne transmission, feeding of tainted prey to nestlings, consumption of infected prey, cannibalism, and snout to snout contact during face biting between adults or between infected adults and nestlings.

The authors strike water-borne transmission and tainted baby food straight away, because the fossil record doesn't allow us to explore these options - we've never found a tyrannosaur nest, and even if we did, it's possible that a baby would die well before such large lesions could develop. Consumption of infected prey is eliminated as well, as we've never found evidence of the infection in any of the species tyrannosaurids are known to have preyed upon.

This leaves two methods of transmission observable in the fossil record: snout to snout contact during face-biting and cannibalism. These are both known to be part of tyrannosaur lives; while the bite marks of smaller tyrannosaurids such as Daspletosaurus and Albertosaurus are harder to distinguish, those left by T. rex are unmistakable. And they left them on each other often. They appear to have been aggressive towards one another, using this face-biting behavior to spar over territory, mating rights, carrion or felled prey, or some other contentious aspect of tyrannosaur life. This behavior probably helped spread the disease.

Once infected, the Trichomonas-like parasite would have resided as a film in the tyrannosaur's throat. A badly infected, lesion-bearing individual, as Sue seems to have been, would find swallowing difficult, eventually falling to starvation.


Illustration by Chris Glen of The University of Queensland, via the PLoS ONE paper

Make Me This

Let's imagine that there's a parallel me whose tastes and interests were combined into a sort of mushy goo with those of my grandma.

That me would want this on his wall.



Come to think of it, this me kind of wants it, too.

Anchiornis

Anchiornis huxleyi, from the Nature paper.

A strong piece of evidence for the theropod origin of birds was announced last week, in an early online version of the current issue of Nature (click for original paper by Xu et al). From the fertile Jurassic strata of northeastern China comes Anchiornis huxleyi. This extravagantly feathered theropod of the troodontid family predates the earliest known bird, Archaeopteryx, and is a blow to the "temporal paradox" argument against the theropod origin.

There are three groups that make up the clade Paraves. The Troodontids, which include this new find; the Avialans, which include Archaeopteryx and later birds; and the Dromaeosaurids, which include those dinosaurs popularly regarded as the "raptors." Paleontologist Xing Xu and colleagues note that with this discovery, basal members of each of these groups have been found which feature a "four-winged" body plan. It appears that long feathers first evolved on the outer (distal, in anatomical terminology) end of the limbs, meaning that the scales we see on the feet of most modern birds was a later adaptation.

In all this further points to the idea that the first flying vertebrates evolved from an arboreal, gliding ancestor. I'm interested to see if a future study extends the climbing function recently attributed to Cretaceous dromaeosaur sickle claws to earlier, Jurassic maniraptors.

Dinosaurigami

Cool!


These origami ornithodires were made by Nicolás Gajardo Henríquez.



More members of his paper menagerie are featured on his Flickr photostream. Way cool!

Carnotaurus by Sideshow

From Sideshow:

Over 60 million years ago, the once-lush jungles of what would later be known as Patagonia have withered, the dry ground cracked and thirsty. Food has become scarce for the prehistoric beings that roam these lands, and as the day comes to a close, the Carnotaurus has yet to find sustenance. With the sun setting, the young bull becomes agitated and wrestles in his hunt.

This dynamic maquette captures the grace and power of this ancient animal of the Cretaceous Period. Designed with the insight of renowned paleoartists, each piece is cast in high-quality polystone, hand finished and hand painted to exacting standards.

I can't really even imagine dropping almost two hundred dollars for something like this right now. First in line would be the Vasque Sundowners I've been eyeing for a while. But if four hundred dollars was handed to me, with the stipulation is must be spent on fun stuff, well, you'd soon find me wearing some fine hiking boots and figuring out where to place my new carnotaurus maquette. Sick.

Hat tip to the Dinosaur Toy Blog! Go there to see some fantastic close up photos, which show incredible detail.

Gertie

I picked up this little dude earlier this summer at a Bedford, Indiana antique mall. Little ceramic sauropod. Sort of reminds me of Gertie, a little bit.

You know, Gertie:

Into Action!

It's almost Halloween, and someone needs our help. Anyone with a high level of skill working with textiles, I beseech thee: help this woman! "I am seeking, she says, "a Dinosaur costume (triceratops!)that is a dress with a tail and preferrably lil claw mittens."

What's more, her friend needs help, too! One person can't fix the economy. Or settle this darned American health care debate. But one person does have the power to make this halloween the very specialest for one, dare I say both, of these women.

If either of these fine ladies happens to bop on over to this humble blog, a couple words of advice, if I might be so bold. How about something a little less vanilla? How about the spiked sauropod Amargasaurus? An azhdarchid pterosaur? Oviraptor? A colorful, feather-adorned dromaeosaur? A downy baby tyrannosaur? Parasaurolophus with actual honking crest? Becrowned Styracosaurus? Imagination ladies! Halloween comes around one precious day each year!

My Belt Buckle

I can't believe its taken this long for me to show this off! It's the best piece of dinosaur paraphenalia I own, and I wear it every day. My gorgeous wife, Jennie, bought me this exceptionally awesome and cool tyrannosaurus belt buckle for my birthday this year. She found it on eBay, and as far as I know, it's a unique piece.

From the Golden Book Encyclopedia

I've collected old kid's books, especially those colorfully illustrated childrens' encyclopedias, for the last twelve years or so. They're fun for the strange things we used to teach children as well as the sometimes wonderful art by the illustrators. Here's a dinosaur image I recently found in the 1983 version of The Golden Book Encyclopedia Volume 5 (con-dy). It's credited to a Robert Frank who apparently drew for the Artist Network. It's hard to find any more information than that on the web - I ran across a few references to him, but there are other artists and photographers with similar names. So this may be the one and only piece of the man's work on the web. Apologies for the white bar; that's where the book folded. Click for a much larger view.

Illustration by Robert Frank, from The Golden Book Encyclopedia, copyright 1983 Western Publishing Company, Inc.

The book gives a hint to its age by the photo of the "Stenonychosaurus" model, which now is known to be a species of Troodon. I like this illustration. It is a bit cartoony, with almost a Don Bluth feel, and Compsognathus is anachronistic to the late Cretaceous scene. It's also either a huge version, or the Euplocephalus, Triceratops, and corythosaurs are juveniles. But the drawing does have a nice, solid weight to it. Had I come across this page as a first- or second-grader, I would have lingered on this for a good, long time.

I've got a couple other old dinosaur books on hand that I'll feature in the near future, and I'll keep looking for new ones.

UPDATE: Image now clickable!

Shawty Got Loh, Loh, Loh, Loh, Loh, Loh, Loh, Loh

Photo by MiranC, via flickr

This morning I experienced one of those odd moments that likely gave birth to the idea of "psychic powers." As I scanned my ever-expanding list of Google Reader subscriptions for new morsels of mesozoica, I wondered if any of the science podcasts I subscribe to had hit upon dinosaurs recently. Indeed, the latest item in The Loh Down on Science, "Long Necks," dealt with sauropod neck posture. I don't make a habit of listening to the Loh Down very often, for the simple and shallow reason that Sandra Loh's voice just kind of annoys me. But it was dinosaur related, so I figured I needed to hear what she had to say about the ongoing sauropod neck posture debate.

Not much, naturally, as their scripts are limited to 125 words or so. The episode dealt with Roger Seymour's hypothesis that the sauropod heart could not have possibly supplied its brain with blood if its head was held high - therefore, it is more likely that sauropods held their necks roughly parallel to the ground, feeding over a wide area rather than at the tree tops. I guess what's odd to me is that the original paper was published almost ten years ago, and this issue has been active this year with the SV-POW crew's dissenting paper on neck posture a few months ago. It's a topic that probably deserves a lot more than 125 words to discuss right now, while other recent discoveries, such as the new Australian species, or the discovery of melanosomes preserved in fossil feathers, could be discussed pretty easily in such a medium.

PS. I know, I know. Cool it with the Hip Hop and R&B parodies in my titles...

Raptorex, Raptorex

Whoa! News outlets and the paleoblogosphere have blowed up mightily over last 24 hours with the news of the new tyrannosaurid Raptorex kriegsteini. Brian Switek wrote a thorough description at Dinosaur Tracking. Chinleana's Bill Parker took a detour from his Triassic stomping grounds to mention it. At DinoGoss, Matt Martyniuk poked fun at its silly name. Beyond the dino-blog world, Jerry Coyne wrote it up on Why Evolution Is True and PZ Myers nodded his head Raptorex's way at Pharyngula. Sports Illustrated hasn't commented on it yet, but the NFL season just started, and there's that NL wild card race to keep an eye on--their plate is pretty full.

Raptorex by Todd Marshall

There's a reason Paul Sereno and his team at the University of Chicago picked a name like "Raptorex," and it was to garner the kind of immediate sensation that causes CNN.com to feature the story on its front page, as it did yesterday. Like the name or not - it strikes me a bit Saturday-Morning-Cartoony - it certainly caused a splash, and in a much more tasteful way than the Ida debacle. So what is the big deal about what appears, on the surface, to simply be another small, basal tyrannosaurid from the early Cretaceous?

Raptorex, as noted by Sereno, is almost exactly proportioned like its late Cretaceous relative, Tyrannosaurus rex. Unlike other early tyrannosaurids found in China, Dilong and Guanlong, Raptorex bears the signature stubby, two-fingered arms that have been amusing us since the discovery of T. rex. Previously thought to be a later development, this indicates that it was an adaptation that had use for small predators as well as the giant tyrannosaurids to come.

PS. It helps if you sing the title of this post to tune of "Birthday Sex" by Jeremih. Weird Al, you have your marching orders. Hop to.

More on Velociraptor Feet

I love the outdoors. I love rocks, big and small. I like feeling them, and I like clambering over them. But to see someone scaling a sheer wall, hundreds or thousands of feet in the air, seizes my breath. I can't imagine possessing the kind of focus it would take to perform such a feat. A common occurence in my dreams is a terrible weakness in my hands - I throw a punch and it's no more than a bop from a pillow. Something in me doubts the power in my hands, and I can't help but think they would fail me, lose grip on whatever fissure or outcrop they were holding, and I'd fall to the ground, vulture food.

Image copyright American Museum of Natural History

The above fossil, a national treasure of Mongolia, is such a rare thing that to even imagine it seems unimaginable: an actual interaction between animals, fossilized. It's a protoceratops and a velociraptor, fighting. It's believed that in the midst of their struggle, the pair were either buried in a collapsed sand dune or overtaken in a sand storm.

In the recent paper on dromaeosaur claws, Manning et al add another possible factor in the death grip. They cite a characteristic I had no idea modern perching birds possessed. And in light of the mild neurosis I mention in the opening paragraph, I'm envious.

I've always taken it for granted that some birds sleep while perched. They just do. I've never given it a second thought. It turns out that the bird doesn't have to give it any thought, either. They land on a limb, their foot grasps it. No special effort needed. The tendons that flex their toes are modified so they automatically lock the foot around the branch. If I possessed a similarly built pair of hands, well, I wouldn't need to worry about losing my grip. I'd grab a handhold, my hand would lock on it, and I could doze off. I'm sure my adrenaline would prevent me from falling asleep, but I wouldn't fear falling from the rock face as I vainly counted (bighorn) sheep.

This paper suggests that dromaeosaur feet were adapted similarly, as they have a ridge on the bones that make up their sickle-claw toe. When a pack of them ambushed an Edmontosaurus, that fearsome claw on their second toe would just lock into it. They would go about their bloody business without giving thought to maintaining a hold on their prey.

Perhaps the Velociraptor in Mongolia's treasure was literally locked to that protoceratops. The proto had its attacker's arm in its beak. They'd fought each other to a stalemate. The raptor had nowhere to lock its jaws. As Manning writes, "Unable to reposition its limbs, it was impossible for the Velociraptor to deploy its jaws and finish the attack, like two boxers hugging each other and unable to throw a punch."

Cowboying Up to Science

As I noted in an introductory post when I started this blog, I'm not an "armchair paleontologist," or even a "footstool paleontologist." I'm basically a dude whose childhood enthusiasm for dinosaurs never wore off. Rather, it metastasized into a love of natural history. I was lousy (or was it just lazy?) at math in school. Thus, I withered when it came time to really "cowboy up" and get into the nitty-gritty of science. I pity Mr. Cline, my poor chemistry teacher. And my lab partners, who shouldered the burden of presentations while I did the visual aids.

So I haven't read much in the way of scientific papers, the heavy sort that appear in journals. Until yesterday, when media accounts of the "climbing raptor" story left me feeling that there was something lacking. So I hopped over to The Anatomical Record online and dug into Biomechanics of Dromaeosaurid Dinosaur Claws: Application of X-Ray Microtomography, Nanoindentation, and Finite Element Analysis.

And you know what? Not so scary. Not at all. So much so, it kind of makes me even more angry that journalists - especially science journalists - so frequently get this stuff so wrong. I'm not sure how many of them actually read the papers they report on, once they figure out their angle and run the abstract through the cuisinart of their brain. These are people who are paid to do this stuff. Or in the case of freelancers, whose accuracy is important to their reputations, and therefore their future work.

The formulas used to describe the biomechanics of Velociraptor's claws are, I'll admit, opaque to me. But it certainly isn't my intent to offer a rebuttal on the fine points of the hypothesis. What interested me about this story was the way it took on a popular conception of an extinct animal and looked beyond it. Reading the abstract, discussion, and conclusions, my main difficulty was in vocabulary. But that is easy to learn. It's just a matter of looking it up, which takes mere seconds on the web.

I'm heartened by this little development. I feel more confident that I may be able to make a contribution to the Open Dinosaur Project, for example. We'll see if time permits.

And I hope that what I can do in the future is not just link to a cool story, or paraphrase it with a pithy comment or two of my own thrown in. My intention is to look at popular stories, look at the papers themselves, and maybe provide some extra meat to chew on, stuff other people may have left on the ground. I'll scavenge it, to stretch the metaphor further.

The image of a raptor using that fearsome claw to rip open a larger beast's guts and spill its viscera all over the dusty ground is a pretty picture, I'll admit. Tomorrow, I'll flesh out the newer idea Phil Manning introduces, and how something cool I learned about the feet of extant avian theropods (in fewer letters, "birds") may teach us something about the feet of Velociraptor and its kin.


Image by Olli72, via flickr

Raptors Don't Grow On Trees

A few years ago, Phil Manning at the University of Manchester used a robotic simulation of the dromaeosaur sickle claw to determine how it may have been used - he wanted to test the assumption, popularized by Jurassic Park, that it was a disemboweling tool, perfect for slashing through the bellies of prey dinosaurs. The robo-claw wasn't actually able to slash through the flesh of a pig's carcass; rather, it punctured it. This led to the conclusion that raptors most likely used the claws to maintain a grip on their larger prey while ripping them up with their teeth, leading to a pretty awful, painful death by bleeding.

Manning is continuing to explore the use of dromaeosaurs' claws, and a recent study of the claws of their hands, published in the newest, dino-centric issue of the Anatomical Record, suggests that they could have supported their weight when climbing. In particular, the paper discusses the manual (hand) claws of Velociraptor mongoliensis, whose inner curve had an arc of 127 degrees, which falls between the upper limits of perching bird claws and the lower limits of trunk-climbing bird's claws. Manning also refers back to a 1969 study of Deinonychus antirrhopus, another small dromaeosaur; their pedal (foot) claws had an arc of 160 degrees, which is in line with the upper range of today's trunk-climbing birds, like woodpeckers or the nuthatches which frequent my suet block. Further studies will be devoted to Deinonychus foot claws, of which we have more good specimens than those of Velociraptor.

So the dromaeosaurs, at least the smaller ones, may very well have used their claws to climb trees as well as hang on to their dinners. Lacking any proper paleoart depicting this fascinating new idea, here's an incredibly crappy, dashed-off, proportionally inaccurate one from yours truly.

Image by me, via flickr

Off-Registry Dinosaur Goodies

As mentioned on Friday, I headed to a craft fair this weekend with the wife - the Renegade Craft Fair in Chicago, which was sort of a hipster mecca. I also had intended to get to the Field Museum, but my Cairn Terrier, Gregory, decided to get a case of the barf n' squirts, and it seemed inadvisable to leave him at the parents' house. So I'll have to get back there as soon as I can, and I will document it properly. The Field has been my "home museum" since I was little. It's still a great feeling to walk into the main hall.

The craft fair was packed to the gills and the sun was big, yellow, and relentless, so we didn't hang out too long there. There were a few dinosaurian crafts, intermingled among the ever-popular "cute monsters," ninjas, robots, and woodland creatures, but nothing that blew my top. I decided to take a look at etsy and find see what kind of dinosaurian goodness there was to see. After scanning fifty pages of results for the search term "dinosaur," these two items stood out:

The first is this nifty T. Rex print by Berkeley Illustrations. They do a lot of portrait-style drawings of animals in dapper clothing, and put the most famous dinosaur in a nudie suit.


This Etsy seller creates "make yourself" pop-up card and model kits, including a dinosaur series. Here's the Triceratops greeting card.


Nothing else dinosaur-related really grabbed me by the cajones, though there is certainly a lot of it. One exhibitor at the fair whose work I'm familiar with was Jay Ryan, the Chicago-based poster maker. He had a diptych of two Elasmosaurs (which are marine reptiles) done in his usual style. He was swarmed with people when I stopped by his booth, so I didn't get to speak with him. Unfortunately, the diptych is not displayed on his website, but his poster for the recent Pitchfork Music Festival features a generic sauropod. So that'll do.

Oh, before I go, the title refers to a term I learned from some soon-to-be-bride or another at the fair. Apparently, buying a gift that the blissful couple hasn't specifically registered for is called "going off-registry." As in, "oh yeah, I'd totally go off-registry for that." Just so you know.

Party Hard in the Mesozoic

My lovely wife Jennie sent me an email this morning to tell me, in her words, that "our blog worlds have collided!" At first it was a bit of a surprise, but it actually makes plenty of sense. A party planning blog she follows featured a "Dino Dig" party theme. You know, for kids! This is no surprise, indeed; as has been well-documented, kids love them their dinosaurs.

So, the gist is, you gather some kids up under whatever auspices are appropriate. After hours of preparation on your part, they'll don little $10 hats and throw themselves into digging for "fossils" in sand, making their own "fossils" with plaster, cracking geodes, and so on. Apparently, today's child expects and demands this level of party entertainment. Certainly a fine idea, but it becomes a positively super idea if you include an intense session of natural history education. It would be a good time, for instance, to distinguish between archaeology and paleontology (a spelling lesson ain't gonna hurt, either).

Another of the activities suggested by the good folks at Gala Goose is the papier maché volcano. Volcanoes and dinosaurs are one of those classic pairings in pop culture. In my mind, I connect dinosaurs much more with towering conifers and cycads. But I think I understand the connection. Volcanoes seem to conjure feelings of the primordial - the violent earth releasing its tormented materials in childish tantrums. It seems to be part and parcel with the old idea of the benighted dinosaurs sluggishly dragging their tails across a foreign, inhospitable, fume-belching world. It's a hard image to eject from the public consciousness, I suppose. Popular media like The Flinstones and the comic BC have accustomed us to dinosaurs being pictured next to smoking pillars of rock, portents of their doom. Of course they died: they lived in a world of constant explosions!

On the whole, there was a lot of geological activity during the dinosaur's time: At the beginning of the Triassic, the Earth bore one continent, Pangaea. By the end of the Cretaceous, the continents we know today were pretty well set in place. There were three major extinction events. But that's over 150,000,000 years. Over the course of a human lifetime, even over the span of human history, the dinosaur's world was basically as "stable" as ours. Cataclysmic events happened, but any period of time has its disruptions. Just because you wreck your car today doesn't make it a daily occurence.

Keeping with today's subject here, Jennie and I will be hitting both a craft fair and a museum this weekend. I'll keep an eye out for paleo-centric items at the former, and I'll be sure to fully document the latter, with a report to come next week. Anyhow, enjoy the weekend. Throw a dinosaur party!

The Open Dinosaur Project

So let's say you're interested in studying the ornithischian family tree. Particularly, you're interested in the ways they moved about and how they arrived at them. You've got a large group of dinosaurs who all share a bipedal ancestor, yet three divergent groups independently adopted quadrupedal locomotion: the stegosaurs and ankylosaurs, the ceratopsians, and the duckbills. It's a lot of convergent evolution for this sprawling dinosaur clan. It's a lot of data to collect for human paleontologists. A lot of work.

Solution? Open up the data-collecting end of the research. Thus, the Open Dinosaur Project is born. Using the internet, gather interested people who are willing to wade into the scientific literature to collect measurements of ornithischian limbs.

Living, accessible science. Cool.

The Carls, Buell and Zimmer

Image by Carl Buell, via flickr

Revered natural history artist Carl Buell doesn't do a lot of dinosaur art, but his flickr photostream is definitely worth a look. Some of the pieces are to be featured in The Tangled Bank, a new textbook on evolution by the fine science writer Carl Zimmer. It looks beautiful. Zimmer recently showed off some photos of the printed book on his Discover blog, The Loom. It includes a spread featuring a chart of theropod-bird evolution and a Buell painting of Archaeopteryx.

Zimmer also appeared on the season premiere of RadioLab, talking about one of his favorite subjects, parasites. And he discusses The Tangled Bank on the New York Academy of Sciences' podcast, Science and the City.

Dinosaur Train

Here's something called a "sizzle reel" for a new PBS kids show called "Dinosaur Train."

Sure, maybe we can't say for sure that corythosaurs used their crests to communicate, though it's very reasonable to assume so. But you can't make a kid's show and qualify every single statement with disclaimers. And heck, when I was a kid everything I read or watched about dinosaurs stated conjectures as facts. The important part: it's a really nice looking show that has a good chance of getting tykes hooked on science. And stating a theory like that of the corythosaur's crests plants a seed that gets kids thinking about evolutionary adaptations. The song at the end of the clip is pretty shrill, but I do like how the theme song harkens back to the train songs that made up such a substantial portion of early rock and roll. Nice touch. Some of the folks here have good taste.

Also on the kid's entertainment front: They Might Be Giants is back with a new album and DVD for kids called Here Comes Science. It includes a tune called "I'm a Paleontologist." As an old school TMBG fan, I wouldn't count it among their golden classics, but what the heck. Good on 'em for writing it. Kids should dig it heartily. Read about it at Dinosaur Tracking.

Have a hell of a weekend. Now. Go.

Compsognathus longipes

Photo by chris 9, via flickr

Here's a doozy of a fossil. It's Compsognathus, a small theropod of the Jurassic. This specimen is a female who apparently liked eating lizards. There's one in her tummy there. This is frameable, isn't it?

T-Rexterminator!

From artbyper.com, copyright 2008 Per Haagenson

Is that not one of the most completely boss things you've seen all week? It's by freelance artist Per Haagenson. Check out a big version of it here. It was a freelance piece done for an insecticide company called Orthene. I can only imagine it hanging behind the glowering, icy-eyed CEO of the company.

Tip of the pith helmet to Matt Tames, who happens to be on my production team at the publishing house where I work! He is, coincidentally enough, a paleoartist who has done work for the Indianapolis Children's Museum. He keyed me in on this painting, and it is also his desktop background.

More Threadless Dino-Love

Contributors to Threadless love their dinosaurs! Hot on the heels of the lovely pinata-ceratops and the "USA is Dino-Mite" designs comes "Jurassircus" by Florent Bocognani. Clicky-click the image to see the shirt's page, and if you're so inclined, exchange legal tender to acquire it!

Dinosaurs in Slate

You don't get too many dinosaur stories in the webzine Slate, but it happened on Friday, in an entry of the Explainer column titled "Will we ever run out of dinosaur bones?" The answer in part:

Since humans started searching for dinosaur bones in 1824, it's estimated that we've found remnants from 29 percent of these types, mostly in the last 20 years (a jump largely attributable to increased manpower and discoveries in Argentina and China). If we keep at the current pace of new discovery, it's likely that we'll hit something like "peak dinosaur," with 50 percent of all dinosaur genera discovered, by 2037. Within the next 100 to 140 years, we will have found 90 percent.

I didn't find much in the piece that seemed wrong to my layman's eyes, though I think it's a little weird to say that "paleontologists are always stumbling across new skeletal remains." From what I've read, they usually pick promising or proven sites for digs, and it's usually a rancher or hiker or other everyday bloke who "stumbles" across a bone.

Bad joke time! With a name like Slate, you think they'd have a lot more paleo-content.